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Biodegradable films are considered ideal alternatives to polyethylene films because of their advantages in increasing crop yield and controlling soil pollution. However, the influences of biodegradable film mulching on soil physicochemical environments and water productivity after long-term mulching remain poorly understood. Therefore, a field experiment after long-term mulching (since 2016) was conducted to explore the effects of black biodegradable film (BB), transparent biodegradable film (TB), and traditional polyethylene film (PE) on soil physicochemical environments, aboveground biomass accumulation, grain yield, evapotranspiration, and water productivity (WP) of maize in the 2021 and 2022 in the North China Plain. The results showed that polyethylene films and biodegradable films had a similar ability to preserve soil moisture, promote maize growth, reduce evapotranspiration, and increase WP. Moreover, the performances of BB were more equivalent to PE, and there was no significant difference on WP and yield under BB and PE. Compared with traditional flat planting without mulching (CK), BB and PE significantly increased yield (9.5 % and 12.7 % in 2021; 5.25 % and 6.37 % in 2022) and WP (11.54 % and 21.47 % in 2021; 24.28 % and 23.42 % in 2022). Film mulching treatments increased the soil organic carbon sequestration rate, and the content of soil organic carbon, microbial activity, and urease activity in the 0–20 cm soil layer compared with CK. According to structural equation modeling, the increasing soil water storage because of films mulching positively influenced yield by enhancing enzyme activities which were related to soil nutrients. Over all, these results showed that black biodegradable film is an ideal replacement for polyethylene films under long-term mulching conditions because of its comparable agronomic performance and influence on soil physicochemical environments in the North China Plain.

Integrating water and nitrogen (N) management is critical to addressing contemporary challenges in agricultural development. This research explored using multispectral sensors mounted on unmanned aerial vehicles (UAVs) to monitor N demand via the normalized difference red-edge (NDRE) vegetation index and consequently schedule fertigation. The experiment included eight treatments with four fertilizer levels under both excessive and full irrigation. The four fertilizer levels comprised: high reference treatment based on commercial lab soil tests, sensor-based treatment triggered by an NDRE saturation threshold of 0.95, deficit treatment with base rate at pre-plant and side-dress, and a control treatment without any N application. The performance of each treatment was evaluated through a comprehensive comparison of yield, water productivity (WP), and nitrogen use efficiency (NUE). The sufficiency index (SI) of sensor-based treatment plots reached a threshold of 0.95, allowing spatially variable adjustment of N application for optimal yield with reduced total N input. Reducing N fertilizer in sensor-based treatments resulted in a substantial reduction of 50 %-60 %, though it led to a yield loss up to 12 %. However, NUE parameters such as partial factor productivity, agronomic efficiency, recovery efficiency, and physiological efficiency improved with sensor-based treatments, alongside reduced N leaching. Combining sensor-based treatment with full irrigation demonstrated the best ecological return, showing relatively lower yield reduction but significant improvements in NUE and WP. Further research into economic returns, saturation threshold algorithms for SI, adaptability to diverse environments, and virtual saturation reference is recommended for the widespread adoption of UAV-based N split management among growers.

Optimizing the nitrogen (N) fertilization level and cropping system is critically important for achieving good production performance with low environmental pollution. However, there is a knowledge gap on the relationship between crop production sustainability, water and nitrogen consumption, greenhouse gas (GHG) emission under the change in N application rate under cereal and legume mixed systems. A 3-year field experiment with two cropping systems [sole forage sorghum (SS) and forage sorghum/lablab mixed cropping (SL) with four N fertilizer application rates (N0, 0 kg N ha−1; N90, 90 kg N ha−1; N180, 180 kg N ha−1; and N270, 270 kg N ha−1)] was conducted. Results obtained showed that mixed cropping combined with N fertilization enhanced forage biomass and crude protein yield by 34.0 % and 51.1 %, respectively, particularly in mixed cropping combined with the N180 treatment compared with the N0 level in the sole cropping system. Similar improvements were observed for yield stability and sustainability (2.97 % and 0.95, respectively), which reached maximum values at N180 in the mixed cropping system. In addition, mixed cropping increased the water productivity of dry matter yield (WPDM) and water productivity of crude protein yield (WPCPY) by 17.2 % and 27.6 %, respectively, at 180 kg N ha−1 compared with the corresponding treatments of the sole planting system. Furthermore, mixed cropping combined with appropriate N application significantly improved N physiological efficiency (PEN) and reduced GHG intensity (GHGI), where N application of 180 kg ha−1 N increased PEN by 21.3 % and reduced GHGI by 17.6 % compared with the corresponding monoculture in the mixed cropping system. This study demonstrated that reducing N fertilization in cereal–legume cropping systems can promote forage productivity by optimizing water and N management while decreasing environmental pollution. Therefore, forage sorghum mixed with lablab and fertilization at 180 kg N ha–1 is a preferable approach for sustainable agricultural production in the Northwest arid region of China.

Various water-saving irrigation (WSI) practices (e.g., dry cultivation, intermittent irrigation, controlled irrigation, shallow-wet irrigation, and rain-gathering irrigation) have been applied to rice cultivation mitigate water scarcity in China. However, in previous studies, these WSI practices have shown different water savings and yield increases, mainly due to different application conditions. A meta-analysis was applied to investigate the responses of the actual evapotranspiration (ETact), irrigation water (IW), rice yield (Y), and water productivity (WP) to WSI practices in different conditions, and 956 data sets were selected from 108 published papers. The results showed that, compared to traditional flood irrigation, rain-gathering irrigation decreased ETact and IW by 25.41 % and 55.7 % respectively, and increased WP greatly by 14.26 % while having a slight decrease in Y. Except for dry cultivation, all WSI practices increased WP by 4.72–14.26 % compared to traditional flood irrigation. The effects of different soil qualities on rice water consumption and production vary; medium soils with high organic content and a pH below 6.5 are better for rice growth. As for rice seasons, WSI practices had the least impact on ETact in middle rice, with an average reduction of 5.84 %, followed by early rice (–12.66 %) and late rice (–18.81 %). Higher mean annual temperature and more precipitation led to more Y under WSI practices. Differences in the effects of mean annual temperature and mean annual precipitation on WP were not significant. Our meta-analysis provides more insight into the effects of water-saving irrigation practices on rice water consumption, yield, and water productivity at various experimental sites. In general, there is considerable variation in the responses of Y and WP to different water-saving irrigation practices, and more evaluation of aspects such as rice seasons, soil properties, and meteorological conditions is needed for optimizing WSI in practice.

In order to explore the efficient use of water and nitrogen for winter wheat under irrigation with micro-sprinkling hose, two-season field experiments were conducted to evaluate the effects of irrigation levels and nitrogen application rate on yield, water productivity (WP) and nitrogen partial factor productivity (NPFP). Three irrigation levels were 60 %, 65 %, and 70 % field capacity (FC) during the reviving to jointing stage, 65 %, 70 %, and 75 % FC after the jointing stage, referred to as W1, W2 and W3, respectively. The irrigating water quota is 30 mm. The five N topdressing period treatments were reviving period + booting stage (N1), jointing + booting stage (N2), reviving period (N3), jointing stage (N4), and booting stage (N5). The results showed that the water consumption, leaf area index, plant height, biomass, grain yield, and NPFP increased with an increase in irrigation amount, and the WP decreased with an increase in irrigation amount. Nitrogen applied during the reviving period was beneficial for increasing grain yield, WP, and NPFP under the irrigation level W1; nitrogen applied during the jointing period was beneficial for increasing grain yield, WP, and NPFP for winter wheat under the W2 and W3 irrigation levels. The W3N2 treatment resulted in the highest grain yield (8.98 t·ha−1), but it was not significant difference from W2N2 (average of 8.92 t·ha−1). After a comprehensive evaluation based on grain yield, WP and NPFP, the appropriate modes of irrigation and nitrogen is the treatment of W2N2 (65 % and 70 % FC irrigation treatments during the reviving to jointing stage and the stages after jointing stage, respectively; the nitrogen topdressing during jointing + booting stage) for winter wheat using micro-sprinkling hose irrigation in North China.

Maize-soybean intercropping systems are widespread in North China. However, the combined effects of supplementary irrigation and different nitrogen (N) application rates on the productivity, water use efficiency (WUE), and N use efficiency (NUE) of such systems remain unclear. A field experiment was conducted in a semi-humid drought-prone region in Northwest China in 2022 and 2023 to assess the interaction effects of supplemental irrigation and different N application rates on the crop yields, WUE, and NUE of a maize-soybean intercropping system and a monoculture system. Three cropping systems were used: maize-soybean intercropping, maize monoculture, and soybean monoculture, with two irrigation treatment scenarios (rainfed and supplementary irrigation at 30 mm) and three N fertilizer rates for maize (240, 180, and 120 kgN ha−1). The land equivalent ratio (LER), ∆water productivity (WP), ∆N harvest index (NHI), and ∆N partial factor productivity (NPFP) of the maize-soybean intercropping system ranged from 1.06 to 1.11, 1.03–1.11, 1.17–1.34, and 1.16–1.28, respectively, demonstrating higher yields and resource of the intercropping system Supplementary irrigation significantly improved yield and resource use by improving the N complementarity effect and increased the economic by 17.24–31.16 %. A 25 % reduction in the N application rate (180 kgN ha−1) for maize increased the NPFP without decreasing the crop yield and WP whereas, a 50 % reduction (120 kgN ha−1) significantly decreased the crop yield and the economic benefits. In summary, supplementary irrigation can improve the productivity and resource use efficiency, and appropriate reduction of N fertilizer will not reduce the yield of intercropping system. This study provides practical insights for enhancing sustainable agriculture by improving water and N use efficiency in maize-soybean intercropping systems in the semi-humid arid-prone regions of China.

Appropriate nitrogen (N) fertilization and planting density management are critical for efficient production of grain maize (Zea mays L.) and for environmental protection. However, the optimal N fertilization and planting density is still not established for forage maize that is cultivated to promote its vegetative growth and utilized for the above-ground vegetative mass. A two-year field experiment was conducted in the rainfed semiarid region of the Chinese Loess Plateau during the 2021 and 2022 growing seasons. The effects of N application rates and planting densities on the dry matter yields and the water- and N-use efficiencies of forage maize were studied. The experiment includes four N application rates (0, 90, 180, and 270 kg ha−1) and three plant densities (70000, 90000, and 110000 plants ha−1), covering the conventional practices of local farmers. The treatments were organized in a randomized complete block design with four replications. Averaged over the three plant densities, N application rate of 180 kg ha−1 resulted in the maximum average aboveground dry matter yield (18.6 t ha−1), crop N accumulation (228.5 kg ha−1), dry matter water productivity (51.9 kg ha−1 mm−1), and dry matter precipitation productivity (62.9 kg ha−1 mm−1) over the two years. Moreover, increasing N application rates significantly increased the soil nitrate-N accumulation (0–200 cm) but reduced the partial factor productivity of applied N fertilizer. Across the three plant densities, the two-year average soil nitrate-N accumulation was 12.6, 32.1, and 75.7 % higher with 90, 180, and 270 kg N ha−1 compared to no N treatment, respectively. The highest soil nitrate accumulation under 270 kg ha−1 N application rate in 2021 (229.5 kg ha−1) and in 2022 (329.7 kg ha−1) may cause severe nitrate leaching loss and potential soil water contamination, driven by intensive rainfalls. Averaged over the four N rates, planting density of 110000 plants ha−1 increased the crop N accumulation and PFP by 21.2 % and 15.8 % in 2021, compared to 70000 plants ha−1, respectively. The interaction of N application and planting density significantly affected the aboveground dry matter yield, crop water consumption, dry matter precipitation productivity, and crop N accumulation in 2021, but the effect was non-significant in 2022. Based on these findings, application of 180 kg N ha−1 and planting density of 110000 plants ha−1 are suggested as an efficient management strategy for improving productivity of forage maize and soil water and N resources utilization in the arid region of the Loess Plateau and similar areas.

The current scenario of water scarcity leads to a seek for new irrigation strategies that maintain agricultural productivity while reducing the pressure on freshwater resources, especially in the Mediterranean region, which has a structural deficit of water sources. In this study, the effects of irrigation with water from different origins were assessed over six consecutive years in soil salinity indicators, tree physiology and yield of mandarin trees in south east Spain. The following treatments were considered: i) freshwater from the “Tagus-Segura” water-transfer canal (TW or Control); ii) reclaimed water from a wastewater-treatment plant (RW); iii) irrigation with TW, except in stage II of fruit development when RW was used (TWc); and iv) irrigation with RW except in stage II when TW was used (RWc). Soil salinity indicators increased in all treatments with respect to Control, except for TWc in winter. However, this increase only led to reductions in net photosynthesis and stomatal conductance in the RW treatment, while gas exchange parameters of trees from TWc and RWc were not negatively affected. Tree vegetative growth was only affected in the long-term, with trees from the RWc treatment having greater canopies. Yield was increased in the TWc and RWc treatments by 23.1 % and 29.5 %, respectively; while it was reduced by 23.5 % in RW when compared to TW. Likewise, differences among treatments in fruit quality traits were also detected. Our results suggest that combining water from different sources could be a viable alternative for irrigating mandarin trees under semiarid conditions with savings of approximately 50 % of fresh water, although the sustainability of soil health should be ensured. In addition, further research is needed to adapt these strategies to other species and cultivar-rootstock combinations.

Water stress is the most important factor limiting crop production in arid and semiarid regions. Cultivating crops using a plastic film mulch can significantly increase crop yields by optimizing soil hydrothermal conditions in semiarid agroecosystems. Therefore, clarifying root adaptability to plastic film mulch cultivation is crucial when attempting to produce stable and high maize yields. A two-year experiment was conducted to investigate the effects of two treatments, no mulching (NM) and plastic film mulching (FM), on the yield, water productivity (WP), and root morphology of spring maize on the Loess Plateau. The results showed that the FM yield (14.31–15.02 t ha–1) significantly increased by 18.6–29.7 % compared to NM (11.03–12.66 t ha–1). The FM treatment also significantly increased dry matter (51.0–61.6 %), leaf area (19.7–25.7 %), and WP (28.8–46.3 %), but decreased ET (8.6–12.8 %). In addition, soil water storage in the FM surface soil layer significantly increased compared to that of NM. Film mulching also produced more robust roots and promoted the convergence of roots towards the surface of the soil, whereas NM roots tended to grow downwards to obtain water from the lower soil layers. The regression analyses indicated that root length (R2 = 0.725, P < 0.01) and biomass (R2 = 0.736, P < 0.01) were positively correlated with grain yield. The results suggested that maize adapts to changes in root morphological behavior under FM. These changes contribute to soil water and nutrient capture and shoot development, which subsequently support the high yields produced under plastic film mulching. Therefore, film mulching is a promising strategy for improving yield and WP and for optimizing root morphology in dryland agriculture.

A thorough understanding of how crops respond to water stress is essential for effective irrigation management under changing climate conditions and declining water resources. Amongst the various methods of irrigation, crop water stress index (CWSI)-based irrigation is popular due to its non-invasive techniques that require less data and can precisely indicate the severity of crop water deficiency. The present study focuses on establishing the upper- and lower-baselines of canopy-air temperature difference (Tc-Ta) for the estimation of the CWSI and to determine the CWSI threshold for maize and wheat crops. The upper- and lower-baseline of (Tc-Ta) was established using the relationship between (Tc-Ta) and vapor pressure deficit (VPD) for different irrigation treatments such as 60 %ETc, 70 %ETc, 80 %ETc, 90 %ETc, and 100 %ETc with irrigation interval of 1-day, 2-days, and 3-days. The study showed that the baselines varied with the growth stages of the crop and with irrigation treatments and reached the maximum in Anthesis and Silking growth stage for wheat and maize, respectively. The threshold of CWSI was estimated by developing a relationship between the normalized values of grain yield (GY) and irrigation water productivity (WPI). For the Rabi wheat, a quadratic correlation was identified between CWSI and WPI (r2 = 0.89), and GY (r2 = 0.93). Similarly, for Kharif maize, a quadratic relationship was noted between CWSI and both WPI (r2 = 0.75) and GY (r2 = 0.85). From the study, it was found that the CWSI thresholds of Rabi wheat and Kharif maize are 0.29 and 0.31, respectively. Based on the study, it can be concluded that by utilizing the thresholds for a winter wheat-summer maize cropping system, high GY and WPI can be achieved.

Intercropping has been widely recognized to have great advantages in terms of increasing yield, controlling pests and diseases, and saving land, particularly in developing countries. Regulated deficit irrigation reduces water consumption and improves water productivity (WP). However, it is unclear whether the combination of intercropping and deficit irrigation could improve crop yield and WP simultaneously. In this experiment, three planting modes, including forage maize (Zea mays L.) monoculture (M), lablab bean (Lablab purpureus L.) monoculture (L), and maize-lablab bean intercropping (ML) were used. Six irrigation modes were set for each planting mode, including severe water deficit (W1), late water deficit (W2), alternate water deficit (W3), late moderate water deficit (W4), early moderate water deficit (W5), and full irrigation (W6). Results showed that compared with M, the ML treatment significantly increased the fresh forage yield (9.8%–17.0%), hay yield (9.5%–13.1%), crude protein yield (22.9%–25.9%), and WP (7.8%–8.7%). The W5 treatment achieved similar fresh forage yield, hay yield, and crude protein yield as that of the W6 treatment but reduced irrigation water by 25% and increased the WP (21.9%–24.8%). Intercropping achieved a high-water equivalence ratio (WER;1.52–1.81) and land equivalence ratio (LER;1.56–1.84), indicating its advantages over monocultures. The W6 treatment had the lowest WER and LER, suggesting that excessive irrigation can reduce the efficiency of utilizing land and water resource in maze-based forage production. Among all treatments, ML–W5 achieved the highest net income and output to input ratio. Overall, intercropping of forage maize and lablab bean with moderate deficit irrigation at an early stage could be used as a high-yield and efficient forage production system in the arid areas of northwest China.

In both arid and semi-arid regions, adopting field mulching can effectively optimize soil moisture distribution, enhance crop yields, and improve water productivity. While acknowledging its advantages, field mulching seems insufficient for maintaining high crop productivity due to the increasing frequency of extreme weather. Furthermore, drought often coincides with critical crop growth stages, necessitating the implementation of agricultural irrigation to ensure normal crop growth. Accordingly, we conducted a three-year field experiment from 2021 to 2023 including three typical field mulching methods (no mulching, NM; straw mulching, SM; plastic film mulching, FM) and three supplementary irrigation strategies (irrigated at the branching stage (V4), W1; irrigated at the pod-filling stage (R2), W2; irrigated at both the V4 and R2 stage, W3). Throughout the entire growth period, we monitored soil moisture conditions for each treatment, measured leaf physiological parameters at crucial growth stages, and assessed soybean yields and water productivity (WP). Our findings indicated that, relative to SM and NM, FM maintains optimal soil moisture balance, augments chlorophyll content, and enhances photosynthesis, resulting in an average yield increase of 17.0% and 38.3% over three growing seasons. Additionally, supplementary irrigation also significantly affects the growth and seed yield of soybean. FMW2 achieved the higher seed yield (4307.5 kg ha−1, 3-year averaged), had insignificant difference with the highest seed yield of 4568.6 kg ha−1, both significantly higher than other treatments. Similarly, the leaf area index, chlorophyll content, net photosynthetic rate (Pn) and transpiration rate (Tr) also presented insignificant difference between FMW2 and FMW3, while WUEleaf (Pn/Tr) of FMW2 obviously higher than that of FMW3. As a result, FMW2 achieved the highest WP of 12.2 kg ha−1 mm−1 over the three growing seasons, compared to the three-year average of the other treatments, the increase ranges from 5.6% to 46.7%. In summary, the FMW2 treatment optimized water distribution to meet the water demands of soybeans during the reproductive growth stages, achieving a beneficial balance between soybean seed production and WP by regulating leaf functional parameters. Future research will explore more specific irrigation scheduling techniques (e.g., precision irrigation, deficit irrigation, and sensor-based irrigation management systems) while integrating innovative agricultural film materials (e.g., biodegradable films) to further enhance crop resilience and productivity under evolving climatic conditions.

Context: Deficit drip irrigation is an advanced agricultural technology widely promoted and applied around the world to maintain/increase yield and quality while simultaneously minimizing water consumption. However, there is still a lack of comprehensive research on the effects of deficit drip irrigation at different stages on apple yield, water productivity, and quality. Objective: The aim was to investigate the effects of deficit drip irrigation treatments (DDITs) on apple yield, quality, and water productivity (WP), and optimize the deficit drip irrigation strategy for apples in the Loess Plateau of China. Methods: a two-year field experiment was conducted with 17 irrigation treatments, including a control treatment (CK, full irrigation (FI)) and four DDITs (D15%, D30%, D45%, D60%) during the bud burst to leafing stage (I), flowering to fruit set stage (II), fruit expansion stage (III), and fruit maturation stage (IV). The optimal irrigation management was determined using the fuzzy Borda combined model, which was based on four different single evaluation models of the TOPSIS method, principal component analysis (PCA), grey correlation analysis (GCA), and membership function analysis (MFA). Results: The DDITs at stage IV decreased midday leaf water potential (Ψs) by 2.57–20.00% compared with CK, and the difference of Ψs between IV-D30%, IV-D45%, IV-D60%, and CK were significant in two years (P

Intercropping has great potential for alleviating arable land competition, improving land output and promoting sustainable agricultural development. However, the applicability of maize-soybean strip intercropping under drip fertigation in arid northwest China remains unclear, especially under various row configurations. A two-season (2022 and 2023) field experiment was performed in the Hexi Region of northwest China to investigate the responses of plant growth, yield performance, water-land productivity and economic profit of drip-fertigated maize-soybean strip intercropping systems to eight row configurations. The results showed that intercropping significantly reduced aboveground biomass accumulation of maize and soybean by 18.77% and 47.81% on average compared to monocropping, respectively. Intercropping significantly decreased the 100-grain weight, ear length and ear width of maize, and reduced the 100-grain weight and pod number of soybean, resulting in reduced grain yields of intercropped maize and soybean (by 13.08% and 48.73%, respectively), but two rows of maize alternating with four rows of soybean (M2S4), three rows of maize alternating with four rows of soybean (M3S4), four rows of maize in wide and narrow rows alternating with four rows of soybean (M4S4-MN), and four rows of maize in wide and narrow rows alternating with six rows of soybean (M4S6-MN) produced greater population grain yield compared to monocropping. Among all intercropping systems, the largest water-land productivity and economic profit occurred in M2S4 (1.61 in 2022 and 1.42 in 2023 for land equivalent ratio; 29.23 kg ha−1 mm−1 in 2022 and 28.22 kg ha−1 mm−1 in 2023 for water productivity; 23,965 CNY ha−1 in 2022 and 23,059 CNY ha−1 in 2023 for economic profit), followed by M4S4-MN (1.53 in 2022 and 1.36 in 2023 for land equivalent ratio; 27.11 kg ha−1 mm−1 in 2022 and 26.58 kg ha−1 mm−1 in 2023 for water productivity; 22,327 CNY ha−1 in 2022 and 22,224 CNY ha−1 in 2023 for economic profit). The M2S4 is thus the optimal row configuration for drip-fertigated maize-soybean strip intercropping systems in terms of grain yield, economic profit and land productivity, while the M4S4-MN is recommended by further considering the efficiency of mechanized sowing and harvesting.

The water-intensive conventional winter wheat–summer maize (WM) double cropping system in the North China Plain (NCP) has significantly decreased the groundwater table. To address this issue, we undertook a two-year field experiment to explore the potential and mechanisms of water-saving and yield increase of five newly designed diversified crop rotations incorporating spring crops (sweet potato, soybean, peanut, spring maize, and millet) into cereal crops compared with the conventional WM (as control). The results revealed that the five diversified crop rotations significantly decreased annual actual crop evapotranspiration by 7–12% and net groundwater use by 21–31% compared to the conventional WM. Sweet potato and peanut-based rotations significantly enhanced annual average equivalent yields up to 32% and economic benefit (+50%, +7%) while improving water productivity by 24–68% compared to WM. Shallow-rooted crops (sweet potato, soybean, peanut, and millet), when used as the preceding crop, improved soil water storage in the 0–180 cm soil layer at the start of the succeeding wheat planting season by 3–9% compared to the conventional WM. These shallow-rooted crops mainly concentrated their root systems in the 0–120 cm soil water, particularly the top 80 cm, complementing the deeper root systems of wheat, which extended down to 180 cm. Consequently, this optimal soil water use regime in diversified crop rotations increased the leaf area index and aboveground biomass of the succeeding wheat and maize crops, increasing total grain yields by 4–11%. Thus, introducing shallowed-root annual crops as preceding crops to the current WM rotation is beneficial for decreasing irrigation inputs, enhancing overall crop productivity, and mitigating groundwater table decline in the NCP.

Drought or/and salinity stress significantly impact maize water use and production. However, comprehensive investigations into the genotype × environment interactions (water or/and salinity) on maize growth, water use, and water productivity (WP) and the physiological controlling factors governing maize production remain lacking. In the present study, we rigorously investigated the effect of water or/and salinity on leaf physiological and morphological characteristics, evapotranspiration (ET), yield and its components (kernel number, KN; thousand kernel weight, TKW) for two genotypes (XY335 and ZD958) over two years, and revealed the mechanisms of yield response to these traits. We found that stomatal conductance (gs) and net photosynthesis rate (A), aboveground biomass (AGB), ET, and KN were higher in XY335 compared to those in ZD958 in both years. Water and salinity stress reduced gs, A, leaf area (LA), the fraction of canopy radiation interception (fPAR), AGB, ET, yield, and KN, while increasing intrinsic water use efficiency. Simultaneous water and salinity stress exhibited an antagonistic effect on WP. Yield was modulated by both ET and yield components. ET was mainly regulated by LA, and only KN was driven by A under salt-free condition. However, under salinity stress, ET was jointly regulated by gs and fPAR, and both gs and A affected KN and TKW. Importantly, a decrease in ET induced by stress did not always lead to yield reduction, provided the reduction remained below about 20% of the maximum value. Thus, mildly regulated deficit irrigation or adapting to low-concentration soil salinity stress was preferable for sustaining yield and improving WP. Nevertheless, a combination of both approaches diminished the water-saving benefits of individual farmland management practices. This study filled the knowledge gap regarding the physiological mechanisms of driving yield variations and offered valuable insights for effective crop water management in drought and soil-salinized regions.

The North China Plain (NCP) is a remarkable agricultural area with severe water scarcity and uneven precipitation, especially in wheat season. Optimizing irrigation strategies to increase water productivity (WP) and achieve higher yield in winter wheat-summer maize rotation is urgently needed and has been a persistent challenge. A four-year field experiment was conducted to explore the impact of irrigation on yield and WP of wheat and subsequent maize under different precipitation year types (dry and normal years, categorized based on the cumulative precipitation from sowing to jointing stage of wheat (P1)). Four irrigation strategies (W0, no irrigation; W1, pre-sowing irrigation; W2, pre-sowing + jointing irrigation; and W3, pre-sowing + jointing + anthesis irrigation) were adopted for wheat, and identical field operations were applied for maize. Results showed that wheat yield was affected by P1 rather than total precipitation. Irrigation improved wheat yield by enhancing evapotranspiration, spike number, grain number, and 1000-seed weight. The water-limited gap in yield and WP between W2 and W1 was significantly higher than those between W1 and W0, and between W3 and W2, implying that W2 was the suitable irrigation strategy in wheat production. Different irrigation in wheat season had no effect on subsequent maize in normal years, but W1 increased maize yield and WP by 13.2–29.3% and 16.1–41.8% compared with other treatments through decreasing soil water storage before maize sowing in dry years. Therefore, we recommended W2 to achieve higher annual yield, WP, and net income in normal years (37.6 mm < P1 < 79.9 mm); and W1 to lower irrigation water consumption and achieve higher WP and economic benefits in dry years (P1 < 37.6 mm), respectively. Overall, optimizing irrigation under different precipitation conditions is an effective strategy to cope with water resource shortages and increase crop yield and WP in the NCP.

The complexities of water issues, in which human factors directly affect the qualitative and quantitative indicators of water resources in a variable, extensive, and undefined manner, make social interactions necessary for the water resources sustainable development. In this situation, local government admins (local divisions of the Water Institutions and Ministry of Agriculture) (LGA) can play a fundamental role in attracting the participation of independent farmers in sustainable agriculture and preserving water resources by modifying support policies. In this study, an agent-based simulation model of social interactions and economic interests of farmers is presented along with different scenarios of support policies as well as random supervision and training by LGA agents to evaluate its impact on the independent decision making of farmers in the form of a complex adaptive system. Questionnaires and expert interviews were used to determine the data and scenarios. Farmers’ adaptation for development technology in irrigation management (DTIM), simulated output of WP, field application efficiency (FAE), and their adaptation speed are influenced by input factors such as assumed cost of sustainable water supply (SWS), mean government expenditure (subsidy count), and the level of supervision and training by LGA. The results showed that the assumed cost of SWS and government supervision and training are the most influential indicators of the farmer agent’s propensity to DTIM with F-value=4375.59 and F-value=1055.10, respectively. The results confirm that appropriate policies in strengthening LGA supervision and training and increasing farmers’ awareness of the importance of long-term water resource sustainability can help achieve more adaptability.

Increases in irrigated crop acreage and frequent droughts during the growing season have caused continual groundwater decline of the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta region. A field experiment was conducted from 2019 to 2021 to determine if combinations of irrigation scheduling thresholds and cover crops (CCs) could improve corn (Zea mays L.) production, water productivity (WP), irrigation water use efficiency (IWUE), and net returns. The irrigation thresholds used for irrigation scheduling were a wet threshold (−40 kPa), a dry threshold (−90 kPa), and no irrigation. The CC treatments were cereal rye (Secale cereale L.), hairy vetch (Vicia villosa R.), wheat (Triticum aestivum L.)-radish (Raphanus sativus L.)-turnip (Brassica rapa L.) mix, and no cover crop. In 2020, CCs reduced corn yield by 9–26% compared to no cover crop. In 2021, wet irrigation threshold treatments had 8% and 9% higher corn yield than no irrigation and dry irrigation threshold treatments, respectively. No irrigation treatments showed higher WP than dry and wet irrigation thresholds, while hairy vetch had higher in WP among CC treatments in year two of this study. Hairy vetch under the dry irrigation threshold had higher IWUE than all other treatments. The no-CC treatments generated $167, $340, and $58 ha−1 more under the wet, dry, and no irrigation treatments, respectively, when averaged over both years. Water conservation was affected by CC selection and irrigation management.

This comprehensive two-year field study investigates the transformative potential of sub-surface drip fertigation (SSDF) as a sustainable alternative to traditional surface flood irrigation coupled with manual nutrient broadcasting in the cotton-wheat cropping system (CWCS). The field experiment was laid out in a split-plot design with combination of two lateral depths (25±2.5 and 30±2.5 cm) and two emitter spacings (30 and 40 cm) in main plots and four fertigation schedules [100% Recommended nitrogen (RDN)-112.5 kg N ha−1) and 125%RDN in 10 &14 equal splits (cotton); 100% Recommended nitrogen and phosphorus (RDNP)-125:62.5 kg NP ha−1) and 80%RDNP in 08 & 10 equal splits (wheat)] in sub plots.Two additional control treatments i.e., C1[Surface flood (SF) irrigation with 100%RDN (105 kg N ha−1 for cotton), 100%RDNP (125:62.5 kg NP ha−1for wheat) applied through manual broadcasting] and C2[SSDF at 20±2.5 cm depth, 20 cm emitter spacing, and 100%RDN for cotton(112.5 kg N ha−1) in 10 equal splits, and 80%RDNP for wheat (100:50 kg NP ha−1) applied in 8 equal splits] were also studied.Results revealed an 18.6% improvement in CWCS productivity under SSDF, when cotton and wheat were fertigated with 125%RDN in 14 equal splits and 100%RDNP in 10 equal splits, respectively in comparison to 100%RDN in 10 equal splits (cotton) and 80%RDNP in 08 equal splits (wheat). Furthermore, lateral placement (25±2.5 cm) depth with emitter spacing (30 cm), and fertigation [125%RDN in 14 equal splits (cotton) and 100%RDNP in 10 equal splits (wheat)] improved crop, irrigationand total water productivity indices by 1.3, 3.1, and 2.1 folds, respectively as compared to SF (C1). Moreover, improvednet returns by 18.7–52.0%was also evident with a SSDF of 100%RDN in 14 equal splits and 80%RDNP in 10 equal splits in cotton and wheat.These findings elucidated that SSDF with drip lateral placement at 25±2.5 cm depth, having an emitter spacing of 30 cm, and fertigation of 125%RDN (140 kg N ha−1) in 14 equal splits(cotton); 100%RDNP (125:62.5 kg NP ha−1) in 10 equal splits (wheat) could be a novel water-savvy concept in sustaining the yield and water productivity of cotton-wheat cropping system under arid agro-ecosystems.

Long-term rotary tillage limit water infiltration and crop productivity in North China Plain (NCP). The practice of subsoiling to fracture plow pans has made beneficial impacts on soil surface structure and water infiltration. Further, appropriate irrigation method coupled with irrigation regime can improve crop productivity in subsoiling condition. A three-year field trial (2020–2023) was carried out to assess the effects of the irrigation regime and the method on winter wheat evapotranspiration (ET), grain yield (GY), water productivity (WP), partial factor productivity from applied nitrogen (PPFN), and economic analysis. The three irrigation regimes were irrigated when soil moisture levels decreased to 70%, 60% and 50% of the field capacity (referred as H, M and L) and two irrigation methods were the surface drip irrigation (SDI) and the micro-sprinkler irrigation (MSI). The traditional flood irrigation with 70% of the field capacity in subsoiling filed was CK. The results showed optimizing irrigation method and irrigation regime significantly influenced ET, GY, WP, PPFN, and net incomes. As the irrigation amount increased, the ET first increased while GY, WP, PPFN, and net incomes increased and then slightly decreased. Based on the three-year average, the maximum GY of 9454 kg ha−1 and the net income of 11089 yuan ha−1 was achieved in SDI-M, which had WP of 2.3 kg m−3 and PPFN of 39.4 kg kg−1. At the same time, SDI-M did not result in much increase of ET (average of 405.1 mm in three seasons). Considering comprehensively ET, GY, WP, PPFN, and net incomes, to irrigate when soil moisture decreases to 60% of the field capacity by surface drip irrigation was the optimal strategy in all aspects. These results will provide a scientific reference for irrigation management in subsoiling wheat field in NCP, as well as in similar production areas worldwide.

North China Plain suffers from the world’s most severe water scarcity and groundwater depletion due to intensive irrigation for agricultural production. It is imperative to reduce irrigation water consumption while safeguarding crop production and food security. This study conducted a quantitative analysis with deficit irrigation strategies for winter wheat using a water-driven AquaCrop model. After model calibration and validation with field experimental data, we analyzed the irrigation water demand, crop yield, and water productivity (WP) of winter wheat under various deficit irrigation scenarios. A set of optimal irrigation schedules were proposed for different climate years, which significantly mitigated irrigation water usage while sustaining high yields and WPs. The results indicated that despite the irrigation water demand of winter wheat under the future climate scenario was slightly higher than that in the historical period, their crop water sensitive periods (reviving, jointing, and flowering) remained the same. Therefore, we recommended adopting the same deficit irrigation schedules for the historical and future periods. In wet years, adopting a 50% deficit irrigation strategy only reduced crop yields by less than 5% compared with full irrigation, but it saved 1000–1100 m3 of water per hectare and contributed a WP higher than 1.88 kg/m3. While in normal and dry years, an optimal 25% deficit irrigation could sustain over 96% of the maximum yield, meanwhile it could save 650–800 m3/ha of water and achieve almost the same WP as full irrigation. These climate-smart irrigation strategies adapting to diverse climatic conditions largely mitigate agricultural water consumption while maximizing crop productivity and water use efficiency, which are essential for achieving precision irrigation and sustainable water management under a changing climate.

This study addresses the low water productivity (WP) of traditional flood irrigation (FI) and the mismatch between the wet zone of surface drip irrigation (SDI) and the root activity layer of fragrant pear. A fixed field experiment was conducted in Xinjiang, northwest China in 2021 − 2023. The experiment was designed as a two-factor, completely randomized trial with three lateral depths of Subsurface drip irrigation (SSDI) gradients set at 20 cm (D1), 30 cm (D2) and 40 cm (D3) and three irrigation gradients: W1 (3750 m³ ha−1); W2 (5250 m³ ha−1); and W3 (6750 m³ ha−1), using SDI (6750 m³ ha−1) and FI (9750 m³ ha−1) as the controls. The effects of these factors on soil moisture, crop water consumption (ETc), fruit quality, yield, WP and net profit were analyzed. The results revealed that the average soil moisture content increased with the lateral depth and irrigation amount. Principal component analysis determined D2W3 to be the treatments with the best overall quality in 2021–2023. On average, compared with SDI and FI, SSDI increased yield by 13.14% and 17.03%, and WP by 44.65% and 137.23%, respectively. A comprehensive Moisture-Yield-Quality-Efficiency evaluation model was established using the Projection Pursuit Classification model based on the Real Coded Accelerating Genetic Algorithm (RAGA-PPC). The comprehensive evaluation was optimized at the lateral depth of 30 cm and an irrigation amount of 6750 m³ ha−1. This study is a crucial reference for further research on perennial fruit trees to improve fruit quality and WP.

The oasis agricultural area of the Hexi Corridor in China supports industrial-scale seed maize production which depends on significant inputs of water and fertilizer, however, the effects of water-nitrogen interaction on seed maize yield and its components, and on water and nitrogen use efficiency in seed maize are unknown, making optimization of inputs impossible. Here, we conducted a study to address these unknowns. Specifically, we established a two-factor split-plot experiment in the Zhangye area of the Hexi Corridor with three irrigation levels of low, medium, and sufficient water supply (50%, 75%, and 100% of the local typical irrigation quota), and three nitrogen application rates of low (160 kg ha−1), medium (280 kg ha−1), and high nitrogen (400 kg ha−1); three irrigation levels without nitrogen fertilizer were used as the control. We found that there was a significant interaction between water-nitrogen combinations, all of which had a significant effect on seed maize yield and its components, and water and nitrogen use efficiency. The yield of seed maize increased with the increase in irrigation quota, but when the irrigation quota reached 100% of the traditional, yield exhibited an increasing and then decreasing trend with the increase in nitrogen application. During the 4-year test period, the maximum yield of seed maize was observed in sufficient water and medium-nitrogen treatment, reaching an average of 9509.38 kg ha−1. Lower nitrogen lowered water productivity, while lower irrigation quotas limited nitrogen utilization. The relationship between irrigation quota, nitrogen application, and seed maize yield was binary quadratic, and the coefficient of determination, R2, reached 0.963–0.985 indicating that the model predicted the yield of seed maize well. The main factor analysis of yield increase showed that the effect of irrigation quota was greater than that of nitrogen application. The optimal combination of water-nitrogen for the highest target yield was obtained with an irrigation quota of 100% of the local typical and a nitrogen application rate of 292.0 kg ha−1-383.2 kg ha−1. This result can be used as a reasonable water and fertilizer management guideline and a technical reference for the seed maize industry in the oasis agricultural area of the Hexi Corridor with objectives of stable and high yields, and reductions in the risk of nitrogen non-point source pollution.

Global population growth and water scarcity are raising concerns about agricultural systems' ability to meet future food, fuel, feed, and fiber demands. Water productivity (WP), the ratio of crop production to water use, is crucial for assessing agricultural resilience and sustainability. Yet, research on WP often lacks long-term observational data to understand the impact of management and climate variability. Long-term monitoring of crop yield and water use, using Eddy Covariance technique, allows for accurate assessment of crop performance and their response to climate change in major cropping systems. In this study, we used data collected over a 20-year period (2001–2020) to investigate the interannual variability in yield (Y), crop evapotranspiration (ET), and water productivity (WP, ratio of Y and ET), and their response to management and climate in three major cropping systems located in Eastern Nebraska: irrigated continuous maize, irrigated maize-soybean rotation, and rainfed maize-soybean rotation. Our results showed significant differences (p < 0.05) in WP between irrigated and rainfed sites, mainly attributed to variations in Y rather than ET, while there was no significant effect of crop rotation on measured responses. WP was 18.4% higher in irrigated maize in rotation relative to the rainfed site. Water input (mm, sum of precipitation and irrigation) was the main management factor in rainfed maize WP (R=0.67, p = 0.05) and Y (R=0.79, p < 0.05). Vapor pressure deficit was negatively correlated with Y in rainfed maize (R=−0.72, p < 0.05) and therefore was considered a determinant in WP (R=−0.7, p < 0.05). For soybean, soil water content had the highest correlations with Y and WP (irrigated: R=−0.77; rainfed: R=0.49, only significant in irrigated sites). These findings can aid in formulating strategies to enhance water productivity and resilience in the US Corn Belt.

Unreasonable irrigation and nitrogen application reduce tomato yield and waste resources. This study explored the effects of water conservation and nitrogen reduction on tomato yield, dry matter, quality, water productivity and nitrogen use efficiency in Northeast China. Experiments were conducted during 2020 and 2021 at three irrigation levels (85–95 %, 75–85 %, and 65–75 % θFC) and three nitrogen application levels (120, 180, and 240 kg hm−2). The optimal water and nitrogen supply patterns were obtained by establishing a newly evaluated Entropy Weight Method−Technique for Order Preference by Similarity to Ideal Solution−Adversarial Interpretive Structure Model (EWM−TOPSIS−AISM). The results showed that the amount of irrigation and nitrogen application significantly affected tomato quality (P ≤ 0.5). Proper deficit irrigation improved tomato quality. Reducing the nitrogen application rate improved nitrogen use efficiency but decreased the tomato yield. Increasing the amount of irrigation increased tomato yield and nitrogen use efficiency. Tomato yield was negatively correlated with water productivity (R= −0.25 in 2020 and R= −0.37 in 2021) and nitrogen use efficiency (R= −0.30 in 2020 and R= −0.20 in 2021). The evaluation results showed that the best water and nitrogen supply mode for our experiment was irrigation at 75–85 % θFC and nitrogen application rate of 180 kg hm−2. The study could promote the sustainable production of greenhouse tomatoes in Northeast China.

On the Loess Plateau, unfavorable late-sowing conditions often arise due to late harvests from the previous season or excessive rainfall during the sowing season, which can delay seed germination, reduce tiller numbers, and decrease winter wheat yields. Few studies have explored whether plastic mulching (PM) can mitigate the adverse effects of late sowing. Consequently, we conducted a 3-year field experiment from 2017 to 2020 on the Loess Plateau combining two mulching conditions [PM and no mulching (NPM)] and three sowing times (normal, 10-day late, and 20-day late sowing). We investigated the combined influence of sowing time and mulching conditions on soil hydrothermal status, crop water productivity (WP), and yield. The results revealed that delayed sowing significantly prolonged emergence times and decreased tiller numbers, leaf area index (LAI), root biomass, and aboveground biomass (AGB). The PM increased soil temperatures, advancing wheat emergence and increasing tiller numbers. Plants under PM had higher LAI, root biomass, and AGB than those under NPM. Moreover, PM reduced ineffective transpiration by accelerating the degradation of ineffective tillers, resulting in higher yields without a corresponding increase in evapotranspiration. The beneficial effects extended to spike numbers, thousand-grain weight, and harvest index. Specifically, PM combined with 10-day late sowing increased yield by 12.8 % compared to NPM combined with normal sowing. Furthermore, under 20-day late sowing, PM mitigated yield losses, reducing them from a 28.7 % decline under NPM to a 12.8 % decline when compared to normal sowing under NPM. We conclude that PM completed compensated for the yield loss under 10-day late sowing and partially alleviated losses under 20-day late sowing. Therefore, combining 10-day late sowing (accumulated air temperature before winter > 430 °C d) with PM was the optimal approach for simultaneously improving yield and WP in winter wheat seasons with unfavorable late-sowing conditions.

Soil mulching has been widely used to improve crop productivity around the world, but how various mulching practices affect soil hydrothermal conditions, water-temperature-radiation utilization and finally grain yield of rainfed maize has been poorly understood. A two-season field experiment was conducted on rainfed summer maize in 2021 and 2022 on the Loess Plateau of China, with six soil mulching practices: flat planting with non-mulching (FPNM), flat planting with full straw mulching (FPSM), flat planting with full black film mulching (FPBF), flat planting with full transparent film mulching (FPTF), ridge-furrow planting with black film mulching on the ridge (RFBF) and ridge-furrow planting with transparent film mulching on the ridge (RFTF). The results showed that compared with the traditional FPNM, the five mulching treatments (FPSM, FPBF, FPTF, RFBF and RFTF) greatly regulated root-zone soil hydrothermal conditions and resulted in obvious soil drying-wetting alternation, which significantly changed the daytime average root-zone soil temperature in the 0 – 25 cm soil layer (by − 1.1 ℃, − 1.9 ℃, + 2.7 ℃, − 1.6℃ and + 0.8 ℃, respectively) and significantly reduced crop evapotranspiration. The five mulching treatments promoted the root growth, leaf area index and canopy light interception rate due to the improved soil water and/or temperature conditions. The structural equation modeling indicated that soil hydrothermal condition and water-temperature-radiation use efficiency could directly or indirectly explain 98% of the grain yield variation under various soil mulching practices; radiation use efficiency (RUE) determined maize production in the water-sufficient year (2021), whereas maize production was mainly determined by crop water productivity (WP) in the water-limited year (2022). The RFBF increased maize production most, followed by RFTF. Compared with FPNM, RFBF increased leaf area index by 45.4%, canopy light interception rate by 19.1%, aboveground biomass by 68.8%, 1000-grain weight by 15.1%, grain yield by 58.6%, WP by 71.8%, thermal time use efficiency by 64.6% and RUE by 30.5%. In conclusion, RFBF optimized the root-zone soil hydrothermal conditions for root growth, which in turn promoted aboveground growth and water-temperature-radiation use efficiency, and finally improved the gain yield of rainfed summer maize on the Loess Plateau of China. Therefore, RFBF was considered as a promising agricultural practice to improve rain-fed summer maize production and resource utilization efficiency on the Loess Plateau of China.

Precise water and nutrient regulation are the key to improving fruit quality and water productivity for kiwifruit orchards in Central Sichuan's hilly region where seasonal drought is becoming increasingly severe. Here, an experiment was set up to clarify how water-potassium coupling at different growth stages affects kiwifruit yield, water/potassium productivity and quality. A conventional fertigation was set as the control treatment (CK), and two water deficit treatments (60% and 80% CK, denoted as LW and HW, respectively) with three potassium (K) deficit levels (40%, 60% and 80% CK, denoted as LK, MK and HK, respectively) were applied at each growth stage of the cultivar “Jinyan” kiwifruit. The phenolic compounds and key enzyme activities were evaluated, in addition to the yield and traditional physical and nutritional properties. Results showed that the water and K deficit would reduce the yield of kiwifruit, however the yield of HWMK treatments at stages I and II showed no significant differences compared with CK (P > 0.05), HWMK treatment at stage III even increased the fruit yield. Water productivity (WP) and K partial factor productivity (KPFP) showed a trend of HW>LW, and reached the highest in HWMK treatment at all growth stages. The physical qualities were more affected by water, especially at stages I and II. HWMK treatments at stages I and II significantly increased fruit firmness by 30.20% and 21.56%, respectively (P 0.05). The correlation analysis revealed a highly significant correlation between fruit nutritional qualities and key enzyme activities (P

Water stress, improper fertilization practices, and agricultural waste pollution severely reduce soil fertility and limit agricultural sustainability on the Loess Plateau. Organic fertilizer application is an efficient method for improving soil water and nutrient availability and grain yield in semi-arid and arid areas. However, the impact of bio-organic fertilizer derived from agricultural waste on soil characteristics and wheat yield and the optimum bio-organic fertilizer substitution rate in semi-humid drought-prone areas remain unclear. A two-year field study was conducted to explore the effect of combined bio-organic and chemical fertilizer application on soil moisture, hydraulic properties, soil structure, soil organic carbon (SOC), total nitrogen (TN), grain yield, and water productivity (WP). Six different treatments were designed: no fertilization (CK), conventional chemical fertilization (CF), and bio-organic fertilizer treatments substituting 25% (OF25%), 50% (OF50%), 75% (OF75%), and 100% (OF100%) of the chemical N fertilizer. From the seedling to over wintering stage, the OF75% and OF100% treatments generally improved soil water storage (SWS) and soil water content (SWC) within the 0–100 cm soil layer compared to the CK and CF treatments across both growing seasons. Bio-organic fertilizer substitution significantly reduced soil bulk density by 4.0–5.6% and enhanced soil porosity by 4.2–5.9% in the 0–40 cm soil layer. Moreover, bio-organic fertilizer substitution significantly increased soil saturated hydraulic conductivity and water content, improved aggregate size distribution, and enhanced SOC and TN contents in both years. The OF75% treatment produced the highest aboveground biomass, yield components, grain yields, and WP, attributed to the improved soil physical environment and nutrient contents. Notably, the OF75% treatment increased the average wheat yield and WP by 21.1% and 24.9%, respectively, relative to the CF treatment across both growing seasons. The measured soil properties strongly correlated with wheat yield, yield components, and WP. Thus, the OF75% treatment is an appropriate and promising fertilization management strategy to alleviate water stress, improve soil properties, and promote crop production in semi-humid drought-prone regions.

Tomato (Solanum lycopersicum L.) is an important vegetable crop around the world, and water scarcity and soil salinization are two major unfavorable factors limiting the fruit yield and quality of greenhouse tomato in arid and semi-arid regions. The application of exogenous silicon has been reported to enhance tomato yield under salt or drought stress, but its effect under combined salt-drought stress remains unclear. A two-season (autumn 2021 and spring 2022) experiment was conducted with three irrigation levels (I1, 90%−100% θf, where θf is the field capacity; I2, 70%−80% θf; I3, 50%−60% θf), two soil salinity levels (S0, 0.1%, g/g; S1, 0.4%, g/g) and two silicon application rates (T0, 0 mM; T1, 2.4 mM) to explore their combined effects on leaf silicon content, photosynthetic parameters, fruit yield, nutrient yield, crop water productivity (WP), nitrogen uptake and utilization, nutrient water productivity (NWP) and economic benefit of drip-irrigated greenhouse tomato. The results showed that deficit irrigation and salt stress exerted significant inhibiting effects on leaf silicon content, photosynthetic parameters, tomato yield, and water-nitrogen productivity, but the inhibition was alleviated by silicon application, which increased leaf silicon content by 67.0%, net photosynthetic rate (Pn) by 25.3%, fruit yield by 12.3%, WP by 11.9%, nutrient yield by 10.0% (titratable acids) - 27.4% (soluble sugars) and NWP by 9.2% (titratable acids) - 26.1% (soluble sugars) on average. The average fruit yield over the two growing seasons was 66.01, 54.29 and 44.31 t ha−1 under I1, I2 and I3, and the silicon application increased average leaf silicon content by 71.9%, 65.2% and 63.0%, Pn by 11.1%, 12.9% and 7.6%, and fruit yield by 12.8%, 16.2%, and 8.1% at the three irrigation levels, respectively. Plant nitrogen uptake (NU) and nitrogen partial factor productivity (NPFP) increased but nitrogen use efficiency (NUE) tended to decrease with the increasing irrigation level, while silicon application improved NUE by 3.9% and 2.2% and NPFP by 13.8% and 11.7% in the two growing seasons, respectively. Silicon application significantly increased net profit by 24.3% and 17.7% in autumn 2021 and spring 2022, respectively. According to the principal component analysis, I1T1S0 ranked first in both growing seasons. The correlation matrix showed that fruit yield was positively correlated with leaf silicon content, Pn, stomatal conductance, WP, NU, NUE, NPFP, nutrient yield and net profit, while it had negative correlation with NWP. In conclusion, exogenous silicon application can improve the fruit yield and nutrient yield of drip-irrigated greenhouse tomato by enhancing leaf silicon content and photosynthetic capability under drought-stressed and salt-affected conditions.

This review emphasizes the significance of combining regulated deficit irrigation (RDI) with woody crops, as they have higher water productivity (WP) and are tolerant to mild water deficits. After conducting the analysis, it was found that for most woody crops, reducing irrigation water by 20.0–30.0% has a negligible impact on yield, typically within a variation range of 10.0%, and it leads to an increase in WP of 10.0–30.0%. When irrigation water is reduced by 40.0–50.0%, the impact on yield varies significantly depending on the species, but the WP generally approaches its highest value; in general, it can increase by 25.0% or more and sometimes even exceed 50.0%. However, when irrigation water is further reduced, it significantly affects yield, and there is a limited increase or even decrease in WP. Moreover, adjusting irrigation amounts during noncritical water demand periods minimizes the impact on yield and fruit size, enhancing water-saving effectiveness. Water-saving techniques trigger various plant responses, improving resistance to water deficits, promoting reproductive growth, and protecting against drought-related damage. Despite potential yield reductions, ongoing research demonstrates positive outcomes in WP, crop yield, and fruit quality in various woody crops. Water-saving techniques offer economic benefits through cost savings and pest reduction, while finding the appropriate balance between water use, yield, and quality is vital for agricultural success and sustainable water resource management. Moreover, water-saving techniques optimize nutrient uptake and heavy metal absorption in woody crop agricultural systems, addressing heavy metal stress, soil salinization, and emissions. Combining multiple irrigation methods, such as partial root-zone drying (PRD), shows immense potential in water conservation and impact on fruits. Integrating PRD with innovative techniques, such as precision irrigation or sensor-based systems, promises remarkable water savings and optimized crop yields, revolutionizing agricultural practices and addressing water scarcity challenges for sustainable irrigation management.

We sought to assess the impact on groundwater of using three types of saline waters to irrigate the halophyte Salicornia bigelovii Torrey in the hyper-arid United Arab Emirates. These were groundwater (GW) at 25 dS m−1, reverse-osmosis brine (RO) from a desalination unit at 40 dS m−1, and the aquabrine (AQ) effluent from land-based aquaculture in tanks filled with RO brine, also at 40 dS m−1. The three waters were applied through bubblers (BUB), pressure-compensated drippers (PCD), or subsurface irrigation tape (SUB). The yields of Salicornia fresh tips, harvest forage, and seed were greatest for AQ applied through BUB, being 650 g m−2. We found 2–2.6 kg m−2 for dry forage yield with AQ through BUB, compared with 1–2.3 kg m−2 for the other waters and emitter devices. The highest water productivities WPI (kg m−3) across all three crop-outputs came from Aquabrine applied by pressure-compensated drippers. We assessed the gross economic water productivity (GEWPI, $ m−3) based solely on gross revenue. The GEWPI was highest for AQ applied through PCD and SUB, namely 5.8–6.2 $ m−3. The value derives primarily from fresh tips. The GEWPl was well above the cost of desalination at $1.5 m−3. We measured drainage and leaching using fluxmeters. The greatest salt load to groundwater came from BUB, being 135–195 kg m−2. For PCD and SUB it was between 14 and 36 kg m−2. Mass-balance calculations of these salt loadings can predict the impact on the saline quality of aquifers. We used an exemplar loading of 75 kg m−2, and results in an annual salinity rise of 2.6 dS m−1 y−1 for an aquifer of saturated depth of 100 m. This significant rate of rise in the salinity of groundwater would represent a continuing deterioration in the utility of groundwater.

So far, many studies have examined the effects of surface (FF) and drip (DF) fertigation compared to surface (FC) and drip (DC) irrigation along with fertilization at different levels of fertilizer on crop yield indices, nutrient use efficiency (NUE), and irrigation water productivity (WP); however, each of them have been conducted under different conditions. Because of the scattered results and the lack of a general conclusion from the published results, conducting a meta-analysis as a structured method for arriving at an overall conclusion regarding the effects of different fertigation methods on different indices is essential. This study was conducted to examine the effects of surface and drip fertigation methods and different fertilizer application levels on crop yield, NUE, and WP. To this end, eight global databases of publications (e.g., Scopus and Web of Science) were reviewed. A total of 5494 studies were extracted, of which 32 studies met the entry criteria for the meta-analysis. To assess the effects of fertigation, each study was used to extract the effect sizes for each index. A total of 119 effect sizes were obtained for crop yield, 85 for NUE, and 84 for WP. The meta-analysis results showed that surface and drip fertigation methods increased the average yield by 20%. NUE and WP on an average increased by 26% and 51%, respectively. Based on the reported results, the optimal fertilizer application level is 75% of the recommended dose, which can reduce fertilizer use by 25% without significantly reducing the yield. In general, fertigation can be recommended as an effective operation for improving the proposed indices examined in both surface and drip fertigation methods.

Deficit irrigation has emerged as a viable approach to increase agricultural water productivity. The objectives of this study were to 1) develop water conservation strategies by investigating responses of green bean (Phaseolus vulgaris) and sweet corn (Zea mays var. saccharata) to four irrigation treatments and 2) evaluate the performance of the Decision Support System for Agrotechnology Transfer (DSSAT) model in simulating growth and yield responses of green bean and sweet corn under four irrigation treatments. A field experiment was conducted using 32 experimental plots, established under a linear move sprinkler irrigation system equipped with variable rate irrigation (VRI) technology, at the Tropical Research and Education Center (TREC), Homestead for two cropping seasons between November and March in 2020–2021 and 2021–2022. The experiment involved four irrigation treatments: full irrigation (FI) (T4), and three levels of deficit irrigation, 75% FI (T3), 50% FI (T2), and 25% FI (T1) with four replications arranged in a completely randomized block design (RCBD) for each crop. The average soil moisture content of the full irrigation treatments was maintained above the management allowable depletion (MAD). Field data collection included various parameters of the crops including plant phenology, plant height, canopy width, fresh and dry biomass, and yield. Results confirmed that all three deficit irrigation treatments did not significantly affect the yield and yield components of the two crops during both seasons compared to the T4. This finding revealed that the highest crop water productivity was achieved from T1, 38.3 and 41.4 kg m−3 for green bean and 54 and 53 kg m−3 for sweet corn during the 2020–2021 and 2021–2022 seasons and up to 75% irrigation water saving could be achieved without affecting plant growth and yield. The DSSAT model performed well in simulating yield and yield components for the two crops in response to the four irrigation treatments. Model evaluation results showed that the minimum mean absolute error (MAE) for green bean fresh pod yield simulation was 2.1 Mg ha−1 with an index of agreement (d-Stat) of 0.6, while for biomass, it was 0.24 Mg ha−1 with a d-Stat of 1. Similarly, for sweet corn, the model simulated fresh cob yield with a minimum MAE of 6.51 Mg ha−1 and d-Stat of 0.9 and biomass with MAE of 1.63 Mg ha−1 and d-Stat of 0.9. Overall, implementing deficit irrigation in green bean and sweet corn fields could result in considerable water savings while achieving acceptable crop yield. The DSSAT model could be also a useful tool to simulate green bean and sweet corn responses to different irrigation scenarios and aid water management decisions under South Florida conditions.

Around 90% of fresh renewable water is being used in Iran, indicating high water stress conditions across the country. Given that agricultural irrigation accounts for the majority of water use and consumption, any efforts to alleviate water stress must focus on enhancing agricultural water management. This paper aims to exhaustively compile the existing literature on the consequences and drivers of water insecurity, and to discuss the strategies balancing food and water security in the context of agricultural water management. Severe water scarcity can be largely attributed to governance gaps in Iran. In addition, inefficient water use, population growth, and warming/drying trends in the recent half a century are other major causes of the water scarcity. Groundwater over-depletion, quality deterioration of aquatic resources, decreased environmental flows and habitat destruction, and water conflicts are the significant consequences of improper water management in Iran. Several water productivity and conservation interventions, drawn from a rich literature, were suggested to improve agricultural water management in Iran. Furthermore, some water-food-energy nexus optimization methods, including changing cropping patterns, modifying energy tariffs, manipulating food diet, and reducing food waste, were discussed. Nexus-based strategies, which aim to achieve a balance between food production and water sustainability, are of high importance in reducing water consumption in the agricultural sector. While there has been a significant focus on improving water productivity and nexus-based measures, it is essential that policy-makers prioritize enhancing the water governance dimensions to effectively address water scarcity and its consequences in Iran. In other words, improving the water governance system is a prerequisite for adopting any strategy aimed at enhancing agricultural water management and coping with water security.

Deficit irrigation (DI) is widely recognized as an irrigation method to save water and increase/maintain yield. The objective of this study was to evaluate the effects of DI on yield and water productivity (WP, the ratio of yield divided by evapotranspiration (ET)) of woody fruits (apple, citrus, pear, peach), herbaceous fruits (strawberry, watermelon) and vine fruit (grape), and to identify the optimal irrigation management strategy for different fruit species groups. For this, we conducted a comprehensive meta-analysis with 591 observations from 56 peer-reviewed papers. Results showed that DI reduced the yield of woody, herbaceous, and vine fruits by 13.74%, 20.51%, and 9.03%, and increased WP by 13.34%, − 2.08%, and 9.89% compared with full irrigation (FI), respectively. Herbaceous fruits were more vulnerable to yield reduction than woody and vine fruits under DI. As for woody fruits, compared with FI, low degree (80%−100% irrigation amount of FI) DI performed better, increasing yield and WP by 0.87% and 9.77%. Woody fruits are suitable for DI in stage I and stage II (bud burst to leafing stage and flowering to fruit set stage), which can reduce the risk of yield reduction and significantly increase WP by 1.86%− 9.28%. Among irrigation methods, surge-root irrigation and sprinkler irrigation under DI performed better for woody fruits, increasing yield and WP by 1.81% and 11.89%, − 5.85% and 43.91%, respectively. In terms of herbaceous fruits, compared with FI, mild degree (60%−80% FI) DI declined the risk of yield reduction and significantly increased WP by 2.25%. DI at stage IV (fruit maturation stage) performed better, which can decrease the risk of herbaceous fruit yield reduction and improve WP by 0.37%. Among irrigation methods, furrow irrigation under DI performed better for herbaceous fruits, increasing yield and WP by − 0.66% and 2.29%. In terms of vine fruits, compared with FI, moderate degree (40%−60% FI) DI performed better, which can significantly increase yield and WP by − 8.05% and 13.87%. Vine fruits are suitable for DI in stage I, increasing yield and WP by 5.38% and 22.13%. For woody fruits, DI is suitable for higher seasonal precipitation (SP > 400 mm) and annual average temperature (AAT ≥ 10 °C). In contrast, for vine fruits and herbaceous fruits, DI is suitable for lower SP (< 200 mm) and AAT (< 10 °C). Our findings provide guidance for precise water deficit management of woody, herbaceous, and vine fruits.

Excessive water and nitrogen (N) input can lead to environmental problems in irrigated areas. By using acidified N loaded biochar with hydrophilic functional groups, it may be possible to reduce water and N usage in rice fields. Therefore, a two–year pot experiment was conducted in northeast China in 2019 and 2020, using a two–factor randomized block design with two irrigation regimes including alternate wet–dry irrigation (IAWD) and continuous flooding irrigation (ICF) as the first factor. The second factor was combinations of NH4Cl acidified N–loaded biochar (NB) and N reduction including the control (local practice, 100%NC0), 10 t ha−1 or 20 t ha−1 NB and 25% less N fertilizer (75%NC1, 75%NC2), and 10 t ha−1 or 20 t ha−1 NB and 50% less N fertilizer (50%NC1, 50%NC2). The effects of NB on N concentrations in surface water, water consumption, N use and water productivity (WP), yields and its components under different irrigation regimes were studied. Results show that exposed to 25% and 50% less N input, the grain yield of C2 was 2.96% and 3.74% higher than that of C1, respectively (two–year average), indicating that NB treatment improved the stability of yield. Stable effective panicles and increased grains per panicle were the main reasons of NB for stabilization of rice grain yield. Compared to the 100%NC0 treatment, 75%NC1 and 75%NC2 significantly reduced the total water consumption by 9.6% and 10.4%, respectively, across two irrigation regimes. The IAWD reduced water consumption during all growth stages, resulting in an average reduction of total water consumption by 10.5%. As a result, the 75%NC2 treatment (1.26 g kg−1, 64.76 g pot−1) had the highest statistical WP and yield. IAWD resulted in the highest increase in surface water ammonium N for the 75%NC1 and 75%NC2 treatments. Under IAWD, from 59 to 99 days after transplanting, the surface water ammonium N concentrations of 75%NC1 and 75%NC2 were 9.7% and 22.5% higher than that of 100%NC0, respectively. This effect was most evident in the later growth stages, resulting in a 5.9% increase in panicle N accumulation and a 10.7% increase in root N accumulation. In summary, using 75%NC2 combined with IAWD was the most effective way to save irrigation water by 10.4%, reduce N input by 25%, promote N uptake in panicles and roots while maintaining rice yield stability.

Increasing scarcity of irrigation water is threatening global winter wheat production and food security. As a major world food crop, irrigation has been pivotal in enhancing the sustainable production of wheat. To ensure food and water security, it is vital to better understand wheat irrigation demands during key growth periods to improve water productivity (WP). Here we combined precipitation and crop water requirements to analyze the impacts of crop water deficit (CWDI) on winter wheat growth periods in the main wheat planting belt of China. The results showed that wheat often had unbalanced water budgets, leading to serious and frequent CWDI in North China Plain (NCP) and Northwestern China (NW), especially during the pre-anthesis periods from greening to jointing and jointing to anthesis. Water deficit during these two phenological periods caused considerable yield reductions of 60% and 55%, respectively, compared to conditions of sufficient water supply. In contrast, in Xinjiang (XJ), extreme and frequent water deficit had a significant negative impact on yield during both pre- and post-anthesis periods. The contribution of different irrigation scenarios to wheat growth and yield was analyzed using the CERES-Wheat model in the Decision Support System for Agrotechnology Transfer (DSSAT). Results indicated that the critical irrigation scenario (CI) was pivotal to alleviating water deficit effects during key growth periods, enhancing wheat growth, and leading to a 51%−92% yield increase compared to rain-fed yields in NCP and NW. Moreover, CI could result in both high WP and high-yield water productivity (HYP) at most CWDI levels (except for extreme). Adding additional irrigation at heading to ensure post-anthesis water requirements were met can simultaneously increase WP and HYP while maintaining higher yields in the extreme water scarcity region XJ. These results imply that winter wheat responses to water deficit vary by growth periods and regions, making optimized irrigation strategies an effective practice to mitigate water shortage and ensure food safety.

Ridge-furrow planting, supplementary irrigation and density regulation are effective measures to improve crop yields in (semi-)arid and drought-prone regions around the world, but their interactive effects on crop evapotranspiration, plant nitrogen uptake, grain yield and its components, water productivity, nitrogen use efficiency and economic benefit of winter wheat are not fully understood. Field experiments were carried out on winter wheat in a semi-humid but drought-prone region of northwest China during 2020 − 2021 and 2021 − 2022. There were two planting patterns (P): ridge-furrow planting with plastic film mulching on ridges (RF) and conventional flat planting (F), two supplementary irrigation amounts (I): 30 mm supplementary irrigation at both overwintering and returning-green stages (I60) and no supplementary irrigation (I0), and three planting densities (D): 240 × 104 plants ha−1 (LD), 360 × 104 plants ha−1 (MD) and 480 × 104 plants ha−1 (HD). The results showed that significant interactive effects of P × I, P × D, I × D and P × I × D on grain yield and water productivity of grain yield (WPg) were obtained, and the interactive effects of P × I, I × D and P × I × D on partial factor productivity of nitrogen (NPFP) and net income (NI) were significant. Compared with F, RF increased grain yield by 10.4%, WPg by 11.9%, water productivity of biomass yield (WPb) by 6.2%, precipitation and irrigation water use efficiency (PIUE) by 10.4%, irrigation water use efficiency (IUE) by 12.0%, agronomic nitrogen use efficiency (ANUE) by 5.3%, NPFP by 10.6% and NI by 17.1%. Compared with I0, I60 increased grain yield by 13.5%, WPg by 7.8%, ANUE by 5.7%, NPFP by 13.7% and NI by 27.9%. Increasing planting density improved soil water consumption, population nitrogen uptake, effective number of panicles per unit area, WPb, PIUE, ANUE, NUtE and total income. Grain yield, WPg, NPFP and NI reached the maximum values at MD under RF, because the presence of plastic film in RF reduced the number of planting rows and resulted in excessive planting density in the plant row at HD compared to F. In summary, the optimized planting density (360 ×104 plants ha−1) combined with ridge-furrow planting and supplementary irrigation is more desirable for balancing grain yield, water productivity, nitrogen use efficiency and economic benefit of winter wheat in the semi-humid and drought-prone region of northwest China.

The knowledge of seasonal nutrient demand is necessary for maximizing potato yield and resources use efficiency under drip fertigation, and it also can effectively mitigate the risk of nutrient leaching caused by excessive fertilization. To explore the coupling effects of irrigation level and fertilization rate on drip-fertigated potato growth, nutrient accumulation and determine the multi-objective optimal irrigation and fertilization regimes, a two-year (2018 and 2019) field experiment was conducted in the sandy regions of northern China. The experiments included three irrigation levels (I60, 60% ETC; I80, 80% ETC and I100, 100% ETC, where ETc is the crop evapotranspiration) and five fertilization rates (N0P0K0, 0 kg ha−1; N1P1K1, 100–17.5–124.5 kg ha−1; N2P2K2, 150–26.2–186.7 kg ha−1; N3P3K3, 200–34.9–248.9 kg ha−1 and N4P4K4, 250–43.7–311.2 kg ha−1, where the ratio of N, P and K was 1:0.17:1.24). The results showed that N, P and K accumulated rapidly from 42th to 95th, 50th to 96th and 46th to 91th days after sowing, respectively. For producing 1000 kg tuber yield, the required amounts of N, P and K were 1.97–4.16 kg, 0.55–0.81 kg and 4.83–7.65 kg, respectively. The uptakes of N, P and K in 1000 kg tubers across all treatments were 1:0.18–0.34:1.61–2.59, with the average N:P:K ratio of 1:0.23:2.05. Besides, irrigation level, fertilization rate and their interaction had significant effects on potato leaf area index, biomass, N, P and K accumulation. Deficit irrigation reduced seasonal LAI, biomass, N, P and K accumulation, tuber yield and apparent fertilizer recovery (AFR), but increased water productivity. High fertilization rate was conducive to promoting nutrient absorption, plant growth and improving tuber yield, while it reduced the unit nutrient productivity. The AFR increased first and then decreased with the increase of fertilization rate. To simultaneously achieve high potato yield and resources use efficiency, a multi-objective optimization model was established using the binary quadratic regression analysis between tuber yield, net income, water productivity, AFR and water–fertilizer regimes, which showed that tuber yield, net income, water productivity, and AFR could obtained ≥ 90% of their maximum values simultaneously when the irrigation interval was 204–262 mm and fertilization (N-P-K) interval ranged from 200–24–248 to 247–42–306 kg ha−1. The findings can provide useful information for optimizing irrigation and fertilization regimes in sandy regions of northern China.

Water shortage caused by irrigation has been widely concerned around the world. Despite the application of various water-saving technologies to improve irrigation efficiency and water productivity, irrigation water consumption is still high or even rising in some regions due to land expansion. Similarly, China has substantially increased the application of water saving technology in recent decades but water shortage are still remained. The aim of this research is to clarify how water productivity and irrigated area expansion have affected irrigation water consumption and food production using satellite-based evapotranspiration and gross primary productivity data over the past decades. The results clarify the significant contribution of irrigated area expansion to the increase of irrigation water consumption and highlight the importance of water productivity in slowing down the increase of irrigation water. Spatially, the contributions of the two factors are different in each sub-region. In Northeast China, 65.10 % of the increase in irrigation water was caused by irrigated area expansion, while 27.97 %, 17.31 % and 12.95 % respectively in the upper and middle reaches of the Yellow River, Xinjiang and Southwest China, resulting in a significant irrigation water increase in these four sub-regions. Contrarily, in Huang-Huai-Hai Plain, although land expanded by 23.5 %, irrigation water consumption increased only by 4.1 % due to 44.7 % of increase in irrigation water productivity. For the whole China, from 1982 to 2017, driven by the 44.5 % increase in national irrigation water productivity, irrigation water consumption only increased by 34.8 %, while gross primary productivity increased by 94.8 %. This study illustrates the crucial role of water-saving technology and irrigated area expansion played in ensuring China's water and food security. It suggests that water saving and increasing water supply are equally important for China's future agricultural water management. • Improvement in water productivity can not offset irrigation water increase in China. • Increase in water productivity helps to reduce irrigation water consumption in most regions. • Expansion of irrigated area is the main reason of irrigation water increase. • Water productivity improvement results in 94.8 % increase in China's agricultural productivity with 34.8 % water increase. [ABSTRACT FROM AUTHOR]

Biodegradable films are considered ideal alternatives to polyethylene films because of their advantages in increasing crop yield and controlling soil pollution. However, the influences of biodegradable film mulching on soil physicochemical environments and water productivity after long-term mulching remain poorly understood. Therefore, a field experiment after long-term mulching (since 2016) was conducted to explore the effects of black biodegradable film (BB), transparent biodegradable film (TB), and traditional polyethylene film (PE) on soil physicochemical environments, aboveground biomass accumulation, grain yield, evapotranspiration, and water productivity (WP) of maize in the 2021 and 2022 in the North China Plain. The results showed that polyethylene films and biodegradable films had a similar ability to preserve soil moisture, promote maize growth, reduce evapotranspiration, and increase WP. Moreover, the performances of BB were more equivalent to PE, and there was no significant difference on WP and yield under BB and PE. Compared with traditional flat planting without mulching (CK), BB and PE significantly increased yield (9.5 % and 12.7 % in 2021; 5.25 % and 6.37 % in 2022) and WP (11.54 % and 21.47 % in 2021; 24.28 % and 23.42 % in 2022). Film mulching treatments increased the soil organic carbon sequestration rate, and the content of soil organic carbon, microbial activity, and urease activity in the 0–20 cm soil layer compared with CK. According to structural equation modeling, the increasing soil water storage because of films mulching positively influenced yield by enhancing enzyme activities which were related to soil nutrients. Over all, these results showed that black biodegradable film is an ideal replacement for polyethylene films under long-term mulching conditions because of its comparable agronomic performance and influence on soil physicochemical environments in the North China Plain. • Long-term biodegradable film mulching (BDM) significantly impacted soil structure. • The effects of long-term BDM on soil physicochemical environments were similar to PE. • Effects of BDM and PE on the maize production were determined after long-term mulching. • The BDM and PE increased yield through affecting soil physicochemical environments. • Agronomic performance of the black BDM was more similar to PE than transparent BDM. [ABSTRACT FROM AUTHOR]

Integrating water and nitrogen (N) management is critical to addressing contemporary challenges in agricultural development. This research explored using multispectral sensors mounted on unmanned aerial vehicles (UAVs) to monitor N demand via the normalized difference red-edge (NDRE) vegetation index and consequently schedule fertigation. The experiment included eight treatments with four fertilizer levels under both excessive and full irrigation. The four fertilizer levels comprised: high reference treatment based on commercial lab soil tests, sensor-based treatment triggered by an NDRE saturation threshold of 0.95, deficit treatment with base rate at pre-plant and side-dress, and a control treatment without any N application. The performance of each treatment was evaluated through a comprehensive comparison of yield, water productivity (WP), and nitrogen use efficiency (NUE). The sufficiency index (SI) of sensor-based treatment plots reached a threshold of 0.95, allowing spatially variable adjustment of N application for optimal yield with reduced total N input. Reducing N fertilizer in sensor-based treatments resulted in a substantial reduction of 50 %-60 %, though it led to a yield loss up to 12 %. However, NUE parameters such as partial factor productivity, agronomic efficiency, recovery efficiency, and physiological efficiency improved with sensor-based treatments, alongside reduced N leaching. Combining sensor-based treatment with full irrigation demonstrated the best ecological return, showing relatively lower yield reduction but significant improvements in NUE and WP. Further research into economic returns, saturation threshold algorithms for SI, adaptability to diverse environments, and virtual saturation reference is recommended for the widespread adoption of UAV-based N split management among growers. [ABSTRACT FROM AUTHOR]

Optimizing the nitrogen (N) fertilization level and cropping system is critically important for achieving good production performance with low environmental pollution. However, there is a knowledge gap on the relationship between crop production sustainability, water and nitrogen consumption, greenhouse gas (GHG) emission under the change in N application rate under cereal and legume mixed systems. A 3-year field experiment with two cropping systems [sole forage sorghum (SS) and forage sorghum/lablab mixed cropping (SL) with four N fertilizer application rates (N 0 , 0 kg N ha−1; N 90 , 90 kg N ha−1; N 180 , 180 kg N ha−1; and N 270 , 270 kg N ha−1)] was conducted. Results obtained showed that mixed cropping combined with N fertilization enhanced forage biomass and crude protein yield by 34.0 % and 51.1 %, respectively, particularly in mixed cropping combined with the N 180 treatment compared with the N 0 level in the sole cropping system. Similar improvements were observed for yield stability and sustainability (2.97 % and 0.95, respectively), which reached maximum values at N 180 in the mixed cropping system. In addition, mixed cropping increased the water productivity of dry matter yield (WP DM) and water productivity of crude protein yield (WP CPY) by 17.2 % and 27.6 %, respectively, at 180 kg N ha−1 compared with the corresponding treatments of the sole planting system. Furthermore, mixed cropping combined with appropriate N application significantly improved N physiological efficiency (PE N) and reduced GHG intensity (GHGI), where N application of 180 kg ha−1 N increased PE N by 21.3 % and reduced GHGI by 17.6 % compared with the corresponding monoculture in the mixed cropping system. This study demonstrated that reducing N fertilization in cereal–legume cropping systems can promote forage productivity by optimizing water and N management while decreasing environmental pollution. Therefore, forage sorghum mixed with lablab and fertilization at 180 kg N ha–1 is a preferable approach for sustainable agricultural production in the Northwest arid region of China. • Productivity increased by 21.1 % for mixed cropping combined with N fertilization. • Mixed cropping combined with N 180 treatment achieved the highest water productivity and N physiological efficiency. • Mixed cropping combined with moderate N inputs improves sustainability while reducing GHG emissions. [ABSTRACT FROM AUTHOR]

Various water-saving irrigation (WSI) practices (e.g., dry cultivation, intermittent irrigation, controlled irrigation, shallow-wet irrigation, and rain-gathering irrigation) have been applied to rice cultivation mitigate water scarcity in China. However, in previous studies, these WSI practices have shown different water savings and yield increases, mainly due to different application conditions. A meta-analysis was applied to investigate the responses of the actual evapotranspiration (ET act), irrigation water (IW), rice yield (Y), and water productivity (WP) to WSI practices in different conditions, and 956 data sets were selected from 108 published papers. The results showed that, compared to traditional flood irrigation, rain-gathering irrigation decreased ET act and IW by 25.41 % and 55.7 % respectively, and increased WP greatly by 14.26 % while having a slight decrease in Y. Except for dry cultivation, all WSI practices increased WP by 4.72–14.26 % compared to traditional flood irrigation. The effects of different soil qualities on rice water consumption and production vary; medium soils with high organic content and a pH below 6.5 are better for rice growth. As for rice seasons, WSI practices had the least impact on ET act in middle rice, with an average reduction of 5.84 %, followed by early rice (–12.66 %) and late rice (–18.81 %). Higher mean annual temperature and more precipitation led to more Y under WSI practices. Differences in the effects of mean annual temperature and mean annual precipitation on WP were not significant. Our meta-analysis provides more insight into the effects of water-saving irrigation practices on rice water consumption, yield, and water productivity at various experimental sites. In general, there is considerable variation in the responses of Y and WP to different water-saving irrigation practices, and more evaluation of aspects such as rice seasons, soil properties, and meteorological conditions is needed for optimizing WSI in practice. • Water consumption and yield of rice varied with water-saving irrigation practices. • Intermittent irrigation was superior in increasing yield and water productivity. • Lower pH favors rice growth but increases water consumption. • Early rice has the highest yield and late rice has the highest water productivity. • More mean annual precipitation and higher temperature led to more yield. [ABSTRACT FROM AUTHOR]

In order to explore the efficient use of water and nitrogen for winter wheat under irrigation with micro-sprinkling hose, two-season field experiments were conducted to evaluate the effects of irrigation levels and nitrogen application rate on yield, water productivity (WP) and nitrogen partial factor productivity (NPFP). Three irrigation levels were 60 %, 65 %, and 70 % field capacity (FC) during the reviving to jointing stage, 65 %, 70 %, and 75 % FC after the jointing stage, referred to as W1, W2 and W3, respectively. The irrigating water quota is 30 mm. The five N topdressing period treatments were reviving period + booting stage (N1), jointing + booting stage (N2), reviving period (N3), jointing stage (N4), and booting stage (N5). The results showed that the water consumption, leaf area index, plant height, biomass, grain yield, and NPFP increased with an increase in irrigation amount, and the WP decreased with an increase in irrigation amount. Nitrogen applied during the reviving period was beneficial for increasing grain yield, WP , and NPFP under the irrigation level W1; nitrogen applied during the jointing period was beneficial for increasing grain yield, WP , and NPFP for winter wheat under the W2 and W3 irrigation levels. The W3N2 treatment resulted in the highest grain yield (8.98 t·ha−1), but it was not significant difference from W2N2 (average of 8.92 t·ha−1). After a comprehensive evaluation based on grain yield, WP and NPFP , the appropriate modes of irrigation and nitrogen is the treatment of W2N2 (65 % and 70 % FC irrigation treatments during the reviving to jointing stage and the stages after jointing stage, respectively; the nitrogen topdressing during jointing + booting stage) for winter wheat using micro-sprinkling hose irrigation in North China. • Yield and nitrogen use efficiency of winter wheat increased with the amount of irrigation (≤180 mm). • N topdressing at jointing and booting stage under W2 irrigation treatment obtained the highest yield. • Water and N use efficiency improved through optimizing micro-sprinkling hose irrigation and fertilizer management. [ABSTRACT FROM AUTHOR]

Water resources worldwide are limited, especially in desert areas like Saudi Arabia. Therefore, the rational and sustainable management of irrigation water supply is an imperative requirement. This research aimed to assess how different irrigation systems, such as partial root-zone drying (PRD) and regulated deficit irrigation (RDI), would affect the growth of cucumber crops. The study specifically focused on comparing the impact of these irrigation techniques when implemented with surface (S) and subsurface (SB) drip irrigation methods. The research was conducted in both controlled environments and open-field settings in central Saudi Arabia. Additionally, the study aimed to promote the adoption of RDI and PRD irrigation systems among Saudi farmers as a means to conserve essential irrigation water resources. The treatments consisted of two groups: the drip irrigation group with a single line (RDI), which includes full irrigation and deficit irrigation, and the group with the (PRD) for the root zone with two lines with the same irrigation ratios as the first group. The productivity of the RDI-S regular drip irrigation treatment was considered 100 % as the control on which the results of all treatments are measured. The results showed that in terms of irrigation technique, the PRD-SB technique had the highest productivity during the winter season in a greenhouse, with an average of 13.8 kg m−2 for all irrigation levels, while the RDI-SB technique had the highest productivity during the summer season, with an average of 16.1 kg m−2. Regarding irrigation level results, the study showed that an irrigation level of 100 % is the highest yield in all irrigation techniques, with a general average of 14.9 kg m−2 for all irrigation techniques during the winter season and 16.4 kg m−2 during the summer. The study showed that irrigation with the PRD-SB system was the most productive in the open field at all irrigation levels, with an average of 7.3 kg m−2. It could be concluded that using PRD and RDI systems for indoor and outdoor cucumber production can save irrigation water in arid regions. • Determining the precise water requirement using a lysimeter before implementing deficit irrigation is crucial. • The study was conducted in greenhouse and open fields with surface and subsurface drip irrigation. • The study found that the most efficient irrigation method in open fields is (PRD) at 75% of the ETc. • The results showed that 25% water conservation can be maintained without losing yield. • Reducing the amount of water used can increase economic benefits by reducing the need for fertilizers and pesticides. [ABSTRACT FROM AUTHOR]

Appropriate nitrogen (N) fertilization and planting density management are critical for efficient production of grain maize (Zea mays L.) and for environmental protection. However, the optimal N fertilization and planting density is still not established for forage maize that is cultivated to promote its vegetative growth and utilized for the above-ground vegetative mass. A two-year field experiment was conducted in the rainfed semiarid region of the Chinese Loess Plateau during the 2021 and 2022 growing seasons. The effects of N application rates and planting densities on the dry matter yields and the water- and N-use efficiencies of forage maize were studied. The experiment includes four N application rates (0, 90, 180, and 270 kg ha−1) and three plant densities (70000, 90000, and 110000 plants ha−1), covering the conventional practices of local farmers. The treatments were organized in a randomized complete block design with four replications. Averaged over the three plant densities, N application rate of 180 kg ha−1 resulted in the maximum average aboveground dry matter yield (18.6 t ha−1), crop N accumulation (228.5 kg ha−1), dry matter water productivity (51.9 kg ha−1 mm−1), and dry matter precipitation productivity (62.9 kg ha−1 mm−1) over the two years. Moreover, increasing N application rates significantly increased the soil nitrate-N accumulation (0–200 cm) but reduced the partial factor productivity of applied N fertilizer. Across the three plant densities, the two-year average soil nitrate-N accumulation was 12.6, 32.1, and 75.7 % higher with 90, 180, and 270 kg N ha−1 compared to no N treatment, respectively. The highest soil nitrate accumulation under 270 kg ha−1 N application rate in 2021 (229.5 kg ha−1) and in 2022 (329.7 kg ha−1) may cause severe nitrate leaching loss and potential soil water contamination, driven by intensive rainfalls. Averaged over the four N rates, planting density of 110000 plants ha−1 increased the crop N accumulation and PFP by 21.2 % and 15.8 % in 2021, compared to 70000 plants ha−1, respectively. The interaction of N application and planting density significantly affected the aboveground dry matter yield, crop water consumption, dry matter precipitation productivity, and crop N accumulation in 2021, but the effect was non-significant in 2022. Based on these findings, application of 180 kg N ha−1 and planting density of 110000 plants ha−1 are suggested as an efficient management strategy for improving productivity of forage maize and soil water and N resources utilization in the arid region of the Loess Plateau and similar areas. • Effect of plant density on yield and resource use was less than that of N rate. • Dry matter yield and water productivity peaked at 180 kg∙ha−1 N rate. • N application of 270 kg∙ha−1 significantly increased soil nitrate-N accumulation. • Increased N application reduced the partial factor productivity of applied N. • N rate of 180 kg∙ha−1 and density of 110,000 plants∙ha−1 maintained efficient water-and N-use. [ABSTRACT FROM AUTHOR]

Maize-soybean intercropping systems are widespread in North China. However, the combined effects of supplementary irrigation and different nitrogen (N) application rates on the productivity, water use efficiency (WUE), and N use efficiency (NUE) of such systems remain unclear. A field experiment was conducted in a semi-humid drought-prone region in Northwest China in 2022 and 2023 to assess the interaction effects of supplemental irrigation and different N application rates on the crop yields, WUE, and NUE of a maize-soybean intercropping system and a monoculture system. Three cropping systems were used: maize-soybean intercropping, maize monoculture, and soybean monoculture, with two irrigation treatment scenarios (rainfed and supplementary irrigation at 30 mm) and three N fertilizer rates for maize (240, 180, and 120 kgN ha−1). The land equivalent ratio (LER), ∆ water productivity (WP), ∆ N harvest index (NHI), and ∆ N partial factor productivity (NPFP) of the maize-soybean intercropping system ranged from 1.06 to 1.11, 1.03–1.11, 1.17–1.34, and 1.16–1.28, respectively, demonstrating higher yields and resource of the intercropping system Supplementary irrigation significantly improved yield and resource use by improving the N complementarity effect and increased the economic by 17.24–31.16 %. A 25 % reduction in the N application rate (180 kgN ha−1) for maize increased the NPFP without decreasing the crop yield and WP whereas, a 50 % reduction (120 kgN ha−1) significantly decreased the crop yield and the economic benefits. In summary, supplementary irrigation can improve the productivity and resource use efficiency, and appropriate reduction of N fertilizer will not reduce the yield of intercropping system. This study provides practical insights for enhancing sustainable agriculture by improving water and N use efficiency in maize-soybean intercropping systems in the semi-humid arid-prone regions of China. • Supplementary irrigation improved the yields and resource use efficiency of the intercropping system. • Reduced nitrogen application did not decrease the yield and resource use advantage of intercropping. • The yield advantage of the intercropping was from the complementarity and selection effects. • The nitrogen uptake advantage of the intercropping was from the complementarity effect. [ABSTRACT FROM AUTHOR]