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Improving the water-use efficiency (WUE) of crops is the most effective way to increase yields in semi-arid regions. Field research was carried out based on a long-term experiment initiated in 2001, aimed to explore the mechanisms of different tillage practices effects on grain yield and WUE of spring wheat. Tillage practices in the research including conventional tillage (CT), no tillage with no straw mulching (NT), conventional tillage with straw incorporation (TS), and no tillage with straw mulching (NTS). The effects of tillage practices on soil's physical and chemical properties, dry matter accumulation, grain yield, dynamics of stress-related substances, and WUE were observed. Soil and plant samples in this research were collected in 2020 (wet year), 2021 (dry year), and 2022 (dry year). The results indicated that NTS improved the soil's physical and chemical properties. The NTS treatment had the lowest soil bulk and pH and the highest total N, NO3--N, and available P. Throughout the whole growth stage, soil water content in the NTS and TS treatments were significantly higher than that of CT by 8.77–20.40% and 2.19–18.83, respectively. Averaged catalase (CAT), peroxidase (POD), and soluble protein across the three years with NTS and TS were significantly increased by 1.26–25.52% compared to CT. Meanwhile, the NTS treatment had the lowest malondialdehyde (MDA) content among the different tillage practices. NTS maintained the highest dry matter accumulation throughout the whole growth stage among different treatments; it was increased by 10.47–73.33% compared with CT. The average grain yields and WUE of NTS across the three years were 6.09–30.70% and 6.79–40.55% higher than other tillage practices, respectively. It is concluded that NTS influences dry matter accumulation and water-use efficiency during the whole growth stage of spring wheat by improving the soil's physicochemical properties and modulating spring wheat substances related to stress, which in turn promotes yield formation. [ABSTRACT FROM AUTHOR]

Increasing water and nitrogen use efficiencies (i.e., WUE and NUE) in dryland agroecosystems to maintain high agricultural output with lower environmental costs, such as minimal soil water depletion and nitrate-N residue, are key responsibilities to assure food security for a growing global population. The impact of N rate on soil water balance, soil nitrate N residue, grain yield, WUE, crop N recovery efficiency (REN), agronomic use efficiency of N fertilizer (AE), and net economic return were examined on maize production on the rainfed Loess Plateau during 2011–2018. Field treatments included four N application rates (N0, no N fertilizer applied; N100, 100 kg N ha−1; N200, 200 kg N ha−1; N300, 300 kg N ha−1). Results showed that compared with N0, grain yield increased by 56, 110, and 115% under N100, N200, and N300, respectively, with corresponding improvements in net economic return of 5497, 10,878, and 11,088 RMB ha−1 yr−1, respectively; no significant difference was detected between N200 and N300. Compared to N0, N fertilization significantly increased WUE through improving photosynthetic WUE (i.e., transpiration efficiency), but there was no significant difference between N200 and N300. Compared to N100, the REN was gradually decreased as N rates increased, AE was not significantly changed under N200 and significantly decreased under N300 due to a decreased leaf photosynthetic NUE. Compared to original soil water storage at 0–300 cm soil depths, after seven years of continuous experiments, treatment of N0 enhanced soil water storage by 52 mm and treatment of N100 had no effect on soil water storage, but treatments of N200 and N300 depleted soil water storage by 73 and 109 mm, respectively. Our findings showed that 200 kg N ha−1 improves WUE and NUE with less environmental cost and should be regarded as the economically optimal N rate on the semiarid western Loess Plateau of China for sustainable maize production. [ABSTRACT FROM AUTHOR]

In the new era of Internet development, short video media has emerged and become the second largest network application in China. While bringing opportunities for the propaganda work of civic and political science, short video also brings difficulties and challenges such as complex network information interfering with the attention of netizens, fragmented communication method not conducive to systematic communication, and algorithmic recommendation technology causing barriers to the reception of information by netizens. In the case that the media short video and the political work need to be constantly updated, we should deal with the short video challenge brought by the media, effectively avoid its negative impact, actively deal with the period of time since the media, and make use of the short video to carry out various forms of educational reform. Facing these challenges, this paper focuses on helping the development of political work in the new era from the aspects of talent training, content optimization, brand building, algorithm standardization, etc. [ABSTRACT FROM AUTHOR]

Due to depleting water supplies and the cultivation of high water-demanding crops such as lucerne, the effect of water deficits in crop production has become a major concern, especially in semiarid regions of China. A six-year field experiment (2012–2018) was conducted to evaluate soil water recovery and soil fertility after lucerne-to-crop conversions on the western Loess Plateau of China. Six rotation treatments (lucerne initially grew from 2003 to 2012 followed by the rotation of other crops or fallow until assessments in 2018) were: (1) lucerne (Medicago sativa L.)–lucerne (L-L); (2) lucerne–fallow (L-F); (3) lucerne–wheat (Triticum aestivum L.) (L-W); (4) lucerne–corn (Zea mays L.) (L-C); (6) lucerne–potato (Solanum tuberosum L.) (L-P); and (6) lucerne–millet (Setaria italica) (L-M). The same crops were grown each year after cultivation during 2013–2018. According to the findings, all rotation types gradually increased the soil water content, with the 0–110 cm soil layer experiencing the maximum soil water replenishment rate, followed by the 110–200 and 200–300 cm soil layers. After converting lucerne to crops, the amount of organic carbon, total nitrogen, and mineral nitrogen in the soil decreased, whereas total phosphorus and accessible phosphorus increased. Soil bulk density was reduced under rotation treatments. Soil water absolute restoration index was the highest under L-F, followed by L-C, L-W, L-P, and L-M. The rate of soil water recovery was 39.5, 33.0, 33.7, 33.5, 29, and 8.2 mm yr−1 under L-F, L-W, L-C, L-P, L-M, and L-L, respectively. The net economic return was greatest under L-C, followed by L-L, L-W, L-P, and L-M. From the analysis of the long-term experimental results, this study shows that the effect of soil water restoration is greatest when continuous alfalfa is converted into wheat, corn, and potato or fallow after 9 years. When the economic benefits and soil moisture recovery are considered comprehensively, corn sown in a ridge–furrow system with fully plastic film annual mulching is the most suitable field management practice after lucerne-to-crop conversion on the western Loess Plateau of China. [ABSTRACT FROM AUTHOR]

Bacterial diversity and its functions are essential to soil health. N fertilization changes bacterial communities and interferes with the soil biogeochemical N cycle. In this study, bacterial community and soil physicochemical properties were studied in 2018 after applying N fertilizers (0, 52.5, 105, 157.5, and 210 kg N ha−1) for a long (2003–2018) and a short (2003–2004) duration in a wheat field on the Loess Plateau of China. Soil bacteria were determined using 16S rRNA Illumina-MiSeq®, and the prediction function was analyzed through PICRUSt. The study showed that N fertilizer significantly changed the diversity and abundance of bacterial communities. The phyla Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi were most abundant, accounting for 74–80% of the bacterial community abundance. The optimum rates of N fertilizer application (N105) maintain soil health by promoting soil microbial diversity and abundance. The bacterial population abundance was higher after short-term N application than after N application for a long duration and lowest with the high N-fertilizer treatment (N210). High N enrichment led to more heterotrophic N-fixing microorganisms (Alphaproteobacteria), in which metabolism and genetic information processing dominated, while cellular processes, genetic information processing, metabolism, and organismal systems were the main functional categories under low N. The phyla Gemmatimonadetes, Actinobacteria, Bacteroidetes, and Chloroflexi were the key bacteria in the co-occurrence network. The genus Saccharimonadales of the superphylum Patescibacteria has a more significant impact under low N treatment. Long-term N fertilization affected the soil pH, NO3-N, and other physicochemical properties, and soil NO3-N was the highest indicator, contributing 81% of the bacterial community function under different N fertilizer treatments. [ABSTRACT FROM AUTHOR]

This study aimed to examine the effect of nitrogen (N) application rate and time on yield, grain filling, starch metabolizing enzymes, and hormones of maize based on a long-term field experiment initiated in 2012. The total N fertilizer dose [(0 (N0), 100 (N1), 200 (N2), and 300 (N3) kg N ha–1] was split into two (T1, one-third at sowing and two-thirds at the six-leaf stage) or three (T2, one-third each at sowing, six-leaf, and eleven-leaf stage) times application. The results showed that the highest yield was obtained under N3T2, N2T1, and N3T2 in 2018, 2019, and 2020, which was 222.49, 185.31, and 194.00% than that of N0 in each year, respectively. N2 and N3 significantly increased the yield through enhancing ears ha–1, grains per plant, and 100-grain weight; however, N2 and N3 did not show a significant difference in yield and above-yield components. In addition, N application time did not significantly change yield under the same N rate. N0 limited the activities of starch metabolizing enzymes, resulting in insufficient accumulation of sucrose and starch. The contents of indole-3-acetic acid, cytokinin, abscisic acid, and gibberellin were decreased under N0 during grain filling. The average grain-filling rate and maximum grain-filling rate (G max) and grain weight increment achieving G max increased under N2 and N3, and the grain-filling parameters were positively correlated with 100-grain weight. In conclusion, 200 kg N ha–1 with one-third application at sowing and two-thirds application at the six-leaf stage is a suitable N supply way to improve starch metabolizing enzymes, regulate hormone content, and enhance grain-filling rates, and thus increasing the maize yield in the semiarid Loess Plateau of China. [ABSTRACT FROM AUTHOR]

Wheat grain yield and nitrogen (N) content are influenced by the amount of N remobilized to the grain, together with pre-anthesis and post-anthesis N uptake. Isotopic techniques in farmed areas may provide insight into the mechanism underlying the N cycle. 15N-labeled urea was applied to microplots within five different fertilized treatments 0 kg ha–1 (N1), 52.5 kg ha–1 (N2), 105 kg ha–1 (N3), 157.5 kg ha–1 (N4), and 210 kg ha–1 (N5) of a long-term field trial (2003–2021) in a rainfed wheat field in the semi-arid loess Plateau, China, to determine post-anthesis N uptake and remobilization into the grain, as well as the variability of 15N enrichment in aboveground parts. Total N uptake was between 7.88 and 29.27 kg ha–1 for straw and 41.85 and 95.27 kg ha–1 for grain. In comparison to N1, N fertilization increased straw and grain N uptake by 73.1 and 56.1%, respectively. Nitrogen use efficiency (NUE) and harvest index were altered by N application rates. The average NUE at maturity was 19.9% in 2020 and 20.01% in 2021; however, it was usually higher under the control and low N conditions. The amount of 15N excess increased as the N rate increased: N5 had the highest 15N excess at the maturity stage in the upper (2.28 ± 0.36%), the middle (1.77 ± 0.28%), and the lower portion (1.68 ± 1.01%). Compared to N1, N fertilization (N2–N5) increased 15N excess in the various shoot portions by 50, 38, and 35% at maturity for upper, middle, and lower portions, respectively. At maturity, the 15N excess remobilized to the grain under N1–N5 was between 5 and 8%. Our findings revealed that N had a significant impact on yield and N isotope discrimination in spring wheat that these two parameters can interact, and that future research on the relationship between yield and N isotope discrimination in spring wheat should take these factors into account. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is the most limiting nutrient for maize, and appropriate N fertilization can promote maize growth and yield. The effect of N fertilizer rates and timings on morphology, antioxidant enzymes, and grain yield of maize (Zea mays L.) in the Loess Plateau of China was evaluated. The four N levels, i.e., 0 (N0), 100 (N1), 200 (N2), and 300 (N3) kg ha−1, were applied at two timings (T1, one-third N at sowing and two-thirds at the six-leaf stage of maize; T2, one-third applied at sowing, six-leaf stage, and eleven-leaf stage of maize). The results show that N2 and N3 significantly increased the plant height, stem and leaf dry weight, and leaf area index of maize compared with a non-N-fertilized control (N0). The net photosynthetic rate, transpiration rate, stomatal conductance, and leaf chlorophyll contents were lower, while the intercellular carbon dioxide concentration was higher for non-fertilized plants compared to fertilized plants. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased with N rate, but the difference between 200 and 300 kg ha−1 was not significant; further, the isozyme bands of POD and SOD also changed with their activities. Compared with a non-N-fertilized control, N2 and N3 significantly increased grain yield by 2.76- and 3.11-fold in 2018, 2.74- and 2.80-fold in 2019, and 2.71- and 2.89-fold in 2020, and there was no significant difference between N2 and N3. N application timing only affected yield in 2018. In conclusion, 200 kg N ha−1 application increased yield through optimizing the antioxidant enzyme system, increasing photosynthetic capacity, and promoting dry matter accumulation. Further research is necessary to evaluate the response of more cultivars under more seasons to validate the results obtained. [ABSTRACT FROM AUTHOR]

• Long-term continuous production of alfalfa resulted in severe depletion of soil water in the Loess Plateau of northwestern China. • Long-term continuous production of alfalfa reduces soil available phosphorus. • To maintain high land productivity, supplementary irrigation, P fertilization, or crop rotation are needed after nine years of alfalfa production in the semiarid Loess Plateau of China. Water availability is a major constraint for crop production in the Loess Plateau of China; thus, improving water use efficiency (WUE) is a main research target. The impact of alfalfa (Medicago sativa L.) growing age on forage yield, WUE, soil water storage, and soil fertility were examined in a 15-yr study in the western Loess Plateau of China. The results of this study indicate that long-term continuous production of alfalfa aggravated the soil water deficit and reduced soil available phosphorus (AP) and the ratio of soil organic carbon to soil total nitrogen, but increased soil organic carbon, soil total nitrogen, and the ratios of soil organic carbon to soil available phosphorus and soil total nitrogen to soil total phosphorus. After the ninth year of alfalfa production, the greatest soil water storage deficit degree was found in the 0–80 cm soil layer (63 %), followed by the 200–300 (57 %) and 80–200 cm (55 %) soil layers. Forage yield and WUE of alfalfa reached their greatest values following six- to nine-yr-old stands, and then decreased gradually. These results suggest that the yield decline with long-term stands of alfalfa may be related to reductions in soil water storage and AP, and their interaction, and the optimal alfalfa growing age should not extend beyond nine years in semiarid conditions. [ABSTRACT FROM AUTHOR]

Soil physiochemical properties are regulated by cropping practices, but little is known about how tillage influences soil microbial community diversity and functions. Here, we assessed soil bacterial community assembly and functional profiles in relation to tillage. Soils, collected in 2018 from a 17-year field experiment in northwestern China, were analyzed using high-throughput sequencing and the PICRUSt approach. The taxonomic diversity of bacterial communities was dominated primarily by the phyla Proteobacteria (32–56%), Bacteroidetes (12–33%), and Actinobacteria (17–27%). Alpha diversity (Chao1, Shannon, Simpson, and operational taxonomic unit (OTU) richness) was highest under no-tillage with crop residue removed (NT). Crop residue retention on the soil surface (NTS) or incorporated into soil (TS) promoted the abundance of Proteobacteria by 16 to 74% as compared to conventional tillage (T). Tillage practices mainly affected the pathways of soil metabolism, genetic information processing, and environmental information processing. Soil organic C and NH4–N were the principal contributors to the diversity and composition of soil microbiota, whereas soil pH, total nitrogen, total P, and moisture had little effect. Our results suggest that long-term conservation practices with no-tillage and crop residue retention shape soil bacterial community composition through modifying soil physicochemical properties and promoting the metabolic function of soil microbiomes. [ABSTRACT FROM AUTHOR]

• Subsoiling could improve soil quality, reduce depletion of soil water. • Subsoiling could improve maize grain yield, WUE, and economic return. • Subsoiling is optimal tillage practice for sustainable intensification of maize production in a semi-arid environment. After widespread application of the fully mulched ridge-furrow system, maize (Zea mays L.) has become a newly dominant crop in the semiarid Loess Plateau of China. Maximization of water use efficiency (WUE) through optimal farming practice are of great importance for sustainable intensification of maize production in this region. In this study, the impact of different tillage practices on soil quality, soil water, grain yield, WUE, and net economic return in a fully mulched ridge-furrow system were examined in a five-year field experiment, to optimize tillage practice for maize production in the area. Four tillage practices (CT, conventional tillage; NT, no-tillage; RT, rotary tillage; SS, subsoiling) were assessed. Compared to CT, SS reduced soil bulk density and penetration resistance, and increased saturated hydraulic conductivity and the percentage of macro-aggregates (≥ 0.25 mm) in the 0–30 cm soil layers, but NT and RT had the opposite effects to above soil physical properties except for macro-aggregates. Tillage practice did not significantly affect soil water storage, evapotranspiration, but annual soil water balance was lowest under SS, followed by CT, NT, and RT. SS increased soil organic C, mineral N and available P at 0−30 cm soil layer compared to CT. Grain yield and WUE under SS were increased by 12 and 15 % compared to CT, NT and RT had no significant effect on grain yield and WUE. Net economic return under NT and SS were increased by 42 and 23 % respectively compare to CT. These results demonstrated that subsoiling could improve grain yield, WUE, and net economic return of dryland maize by improving soil quality and mitigating soil water depletion. In the long-run, although no-tillage increased net economic return, it may not be sufficient to maintain yield and WUE due to deteriorated soil properties and accelerated soil water depletion. Thereby, subsoiling is optimal tillage practice for sustainable intensification of maize production in the semiarid Loess Plateau of China. [ABSTRACT FROM AUTHOR]

In dry environments, potato (Solanum tuberosum L.) is grown under mulching for water conservation and improving tuber yield and nitrogen use efficiency (NUE). A meta-analysis was conducted to determine how mulching improved tuber yield and NUE in potato and how yield and NUE is influenced by fertilization, tillage practices, and growing environment in China. A search of peer-reviewed publications was performed to collect data on the effects of mulching on yield and NUE in potato grown in China. The data included were from field studies with a mulching and a no mulching treatment and data on tuber yield and NUE. A total of 169 publications (17 in English and 152 in Chinese) containing 1802 observations from 105 sites were compiled into the dataset. Mulching significantly increased both tuber yield and NUE by an average of 24% compared to no mulching, respectively. Plastic film mulching was more effective in improving yield and NUE than straw mulching. The yield and NUE increase were highest under plastic film mulching on ridge-furrow plots and straw mulching on flat plots. Mulching was more effective at improving yield and NUE in the Northwest dryland region at a plant density between 55,000 and 70,000 plants ha−1 and with application of synthetic N and P2O5 at rates of 100−200 kg ha−1, K fertilization at 0−100 kg K2O ha−1, and without organic fertilization. Integrated use of organic fertilizer and mulching was found to reduce synthetic N and P fertilizer input by 50% and K fertilizer input by 100% for production without affecting yield and NUE. These results demonstrate that mulching increases yield and NUE in potato in China, but the benefits occur when the growing region, tillage, and fertilization practices are appropriately considered. [ABSTRACT FROM AUTHOR]

Excessive use of water resources is threatening agriculture, other business and populations in China, India and USA, and crop production is expected to play a critical role in the sustainable use of water. In China, plastic mulching is widely employed in crop production, but its impact on agricultural water footprint has not been properly described. A meta-analysis was performed to examine how plastic mulching influences volumetric water availability (VWA), global stress-weighted water footprint per unit of output energy (WFo), and per unit of net economic return in crop production (WFe). Data extracted from 394 published studies in maize (Zea mays L.), wheat (Triticum aestivum L.), and potato (Solanum tuberosum L.) were used in the meta-analysis on crop production at the regional scale and across a range of N fertilization gradients in China. Plastic mulching reduced VWA by 15.3%, 14.1%, and 16.3% in maize, wheat, and potato, respectively, when compared to non-mulching practice, with corresponding reductions of WFo by 33.3%, 28.1%, and 32.1% and of WFe by 14.8%, 31.1%, and 31.0% in maize, wheat, and potato, respectively. Water footprint for crop production increased first and then decreased over the past four decades in China, and was greater in northwest and north central regions of China than in other regions. Under moderate and high N fertilization (>100 kg N ha−1) in dry regions, plastic mulching increased the impact on VWA, thereby reducing WFo and WFe. Water footprint for the production in potato and maize was lower than that in wheat. The meta-analysis demonstrated that plastic mulching practices reduced water footprint while lowering VWA. Therefore, plastic mulching has potential for saving water resource when appropriate growing region and N fertilizer applications are considered. • Plastic mulching (PM) significantly reduced crop's water footprint. • Under moderate and high N input, PM had greater effect on water footprint. • PM was more effective in reducing water footprint in relatively drought environments. [ABSTRACT FROM AUTHOR]

• No-till with straw cover (NTS) improved soil quality and soil water storage before sowing compared to conventional tillage. • NTS and no-till with plastic mulch increased grain yield and precipitation use efficiency through optimizing water use. • NTS is the best tillage practice for sustainable intensification of spring wheat production in semi-arid areas. Drought is a major limiting factor for rainfed spring wheat production on the semiarid Loess Plateau of China. Suitable tillage practices are important for improving precipitation use efficiency (PUE), which is the ratio of grain yield to annual precipitation. To obtain a better understanding of the effects of conservation tillage practices on PUE on the semiarid Loess Plateau, PUE was divided into five steps: precipitation storage efficiency, farmland water consumption rate, ratio of transpiration to evapotranspiration, crop transpiration efficiency, and harvest index. Six tillage practices were assessed in this paper, including conventional tillage with no straw (T), no-till with straw cover (NTS), no-till with no straw (NT), conventional tillage with straw incorporated (TS), conventional tillage with plastic mulch (TP), and no-till with plastic mulch (NTP), based on a long-term experiment initiated in 2001. The impact of tillage practices on soil quality, soil water storage, soil evaporation, biomass yield, and grain yield of spring wheat were monitored in 2015 and 2016. The results show that NTS improved soil quality and soil water storage before sowing. No-till with plastic mulch and NTS increased evapotranspiration but decreased evaporation, thus optimizing precipitation storage efficiency, the farmland water consumption rate, the ratio of transpiration to evapotranspiration, and crop transpiration efficiency, which gave rise to greater aboveground dry matter accumulation and more dry matter accumulation in grain. As a result, grain yield under NTS and NTP was significantly increased by 45 and 41 % compare to T, respectively, with corresponding improvements in PUE of 43 and 39 %. Therefore, both NTS and NTP have potential to substantially increase grain yield of spring wheat and PUE. However, for sustainable intensification in the long-run, NTS is the best combination of tillage and soil surface management for spring wheat production on the semi-arid Loess Plateau of China. [ABSTRACT FROM AUTHOR]

• Tillage systems under plastic mulch showed significant difference among treatments. • Subsoiling with plastic mulching increased soil water content in maize production. • Increased soil water had a positive effect on crop physiological parameters. • Improved physiological parameters translated into increased grain yield and WUE. • Subsoiling could be used for sustainability maize production in semiarid conditions. Water deficit is a threat to agricultural sustainability in the semiarid Loess Plateau of China due to low and variable precipitation. Technologies to improve soil water content (SWC) are necessary for sustainable intensification of maize production. The potential of plastic film mulch and reduced tillage to improve SWC has been reported for the Loess Plateau. However, there has been little research on how tillage management can be integrated with plastic mulching as an approach to improve SWC and maize photosynthesis. A 3-yr field study was conducted to investigate how tillage system influences SWC, photosynthetic performance, grain yield, and grain water use efficiency (WUE g) of plastic-mulched maize in a semiarid environment. Treatments were conventional tillage (CT), rotary tillage (RT), subsoiling (SS), and no-till (NT). Soil water content in the 0–30 cm depth with SS was 24, 31, and 13% greater at the flowering, kernel milk, and physiological maturity stages of maize phenological development, respectively, compared to CT. These improvements in SWC were associated with increased leaf water potential (17%), net assimilation rate (41%), transpiration rate (54%), and stomatal conductance (42%), and decreased intercellular CO 2 concentration (15%) and stomatal limitation (20%) with SS compared to CT. Subsoiling used more water (9%) and increased grain yield by 21% compared to CT, thus enhancing WUE g by 11%. On average, reduced tillage systems had improved performance (SS > NT > RT > CT) for almost all parameters measured. These results show that SS is a viable option for increasing grain production of plastic-mulched maize in semiarid areas. [ABSTRACT FROM AUTHOR]

• Different land use types were chosen to determine soil desiccation. • Long-term maize cultivation with high yield caused a DSLs in the deep soil layers. • Crop rotations are recommended for maize production in the semiarid environment. Sustainable agriculture ensures food security and combats climate change by minimizing reliance on water resources. Maize (Zea mays L.) is commonly grown with plastic mulching practice on the Loess Plateau of China, but its impact on soil desiccation is not well understood. We compared the effects of different land-use, including 17-year continuous wheat cultivation, 19-year pea-wheat rotations, 12-year continuous maize cultivation (high yield), 30-year multi-crop rotations, and 9-year continuous maize cultivation (varying yield) under four nitrogen (N) fertilization rates (i.e., 0, 100, 200, and 300 kg N ha−1). Average crop evapotranspiration during 2009–2020 for long-term continuous wheat, pea-wheat rotation, high-yielding maize, and multi-crop rotations was 222, 201, 277, and 393 mm, respectively, while average effective precipitation from March to September was 329 mm for all treatments. Continuous high-yielding maize cultivation formed a dry soil layer (DSL) in the deep soil profile (>400 cm), which was not found in other cultivation modes. After 9-year continuous high-yielding maize cultivation, 300 kg N ha−1 applying (20.9 Mg ha−1 biomass yield) formed the DSLs in the 360–960 cm soil profiles, while under 200 kg N ha−1 (20.1 Mg ha−1 biomass yield), the soil water content was almost close to the threshold of DSL in the 600–740 cm soil depth; while under 0 and 100 kg N ha−1 (<15 Mg ha−1 biomass yield), the DSL was not found along the soil profile, indicating that DSL formation under continuous maize cultivation was is driven by high N rates (or high yield level). These results suggest that long-term high-yielding maize cultivation with plastic mulching causes severe soil water depletion, resulting in the formation of a DSL in the deep soil profile. To maintain productivity, farmers should not be encouraged to carry out long-term continuous cropping of high-yielding maize in the semiarid environment on the Loess Plateau. [ABSTRACT FROM AUTHOR]

• The immediate and post effects of P fertilization were tested with lucerne. • P fertilization had no effect on leaf NRE, but significantly affected PRE in an age-specific way. • Compared to green leaf N:P, senesced leaf N:P was a better indicator to reflect soil relative nutrient limitation. • Leaf P and N resorption had strong correlations with senesced leaf N:P, and dry biomass of lucerne. Nutrient resorption is one of the key processes of a plant to conserve nutrients and to less depend on soil nutrient availability, which makes the plant more adaptive to adverse environments. Understanding of the effect of phosphorus (P) fertilization on leaf nutrient resorption of legume species is still limited. The aim was to test the responses of leaf nutrient resorption and stoichiometry to immediate and post effects of P fertilization in the Loess Plateau of China where soil P availability is largely restricted due to soil erosion and drought. Nitrogen resorption efficiency (NRE), P resorption efficiency (PRE), green leaf N:P (N:P gr) and senesced leaf N:P (N:P sen) were investigated in 1–3 year lucerne (Medicago sativa L.), a widely used forage in this rainfed region. The NRE and PRE increased with stand age increase from 1 to 3 years. The P fertilization had no effect on NRE, but significantly affected PRE. The PRE increased with P fertilization in the first year and PRE was the highest at 60 kg P 2 O 5 ha−1 in the second and third years. The N:P gr decreased and N:P sen increased with stand age, suggesting more P limitation along lucerne growth. The one-time P fertilization imposed no impacts on NRE but on PRE in an age-specific way. Compared with N:P gr , N:P sen may be more representative to show relative nutrient limitation in soils. Leaf nutrient resorption changed with leaf N:P which indicates the shift of relative nutrient limitation of soils. The P fertilization at 60 kg P 2 O 5 ha−1 could guarantee the greatest PRE, equal NRE and higher dry biomass production in this region. Considering P resource finiteness and production cost, reduced amount or frequency of P fertilization is a desirable way of management for lucerne production in the Loess Plateau of China. [ABSTRACT FROM AUTHOR]

• Organic fertilization increased winter wheat grain yield and water use efficiency without affecting ET in northern China. • The positive effect of organic fertilizer on yield and WUE of winter wheat was greatest when yield levels was <4.0 Mg ha−1. • Organic fertilization was more effective at improving yield and WUE in growing environments with SOM <1.4 % and ET <500 mm. Nitrogen (N) application is a basic practice for increasing cereal yield and efficient utilization of N sources is key to sustainable intensification. A meta-analysis was conducted to determine how organic fertilization (i.e., livestock manure) affects yield, yield variability and water use efficiency (WUE) of winter wheat (Triticum aestivum L.) in northern China, and how this is impacted by N management and growing environment. Organic fertilization significantly increased grain yield and WUE by an average of 18 and 20 % compared to without organic fertilizer, respectively, and also reduced spatial and temporal yield variability. Compared to without organic fertilizer, change in grain yield was +24, +28, and −11 % for treatments of synthetic nitrogen fertilizer plus organic fertilizer with the same level of synthetic nitrogen (NOF), decreased level of synthetic nitrogen fertilizer combined with organic fertilizer (N L OF), and a portion of synthetic nitrogen fertilizer replaced with organic nitrogen fertilizer at the same level of nitrogen (N R OF), respectively. The positive effect of organic fertilizer on grain yield and WUE of winter wheat was greatest when yield levels was <4.0 Mg ha–1. Moreover, organic fertilization was most effective at improving grain yield and WUE in North China Plain when synthetic N application was <150 kg N ha−1 and in growing environments with SOM <1.4 % and ET <500 mm. These results demonstrate that applying organic fertilizer in combination with a decreased level of synthetic N fertilizer is an effective approach for advancing sustainable intensification of winter wheat in northern China, and that greatest benefits with organic fertilization may occur when local environmental factors (e.g., growing region and soil conditions) are appropriately considered. [ABSTRACT FROM AUTHOR]

Sustainably feeding the growing population amid rising global temperatures and dwindling resources is a grand challenge facing mankind. Plastic mulching (PM) is widely used in China aiming to the increase of crop productivity. However, the impact of PM on reactive nitrogen (Nr) emissions and nitrogen (N) footprint has not been explicitly described. In this study, we collected 4051 observations from 394 published papers for potato (Solanum tuberosum L.), maize (Zea mays L.), and wheat (Triticum aestivum L.), and used meta-analysis to investigate how PM affected crop yield, net economic return, Nr emissions, and N footprints including nitrogen footprint per unit of output energy (NFo) and nitrogen footprint per unit of net economic return (NFe) at regional scale and across a range of precipitation and N fertilization gradients in China. The meta-analysis showed that compared to non-PM practice, PM increased grain yield by 25, 27, and 20% in potato, maize, and wheat, respectively, and enhanced net economic return by 19, 29, and 22%, respectively, with corresponding reduction in NFo of 24, 36, and 18% and NFe of 19, 37, and 19%, respectively. Potato and maize had greater energy output and net economic return than wheat. Plastic mulching was more effective in improving net economic return (or energy output) and reducing N footprints (i.e., NFe and NFo) in the semiarid region (i.e., annual precipitation <600 mm) when N was applied at 100-200 kg N ha -1 , especially in potato and maize. Our analysis suggests that the use of PM enhanced grain yield and net economic return while lowering the N footprint without increasing Nr emission. Therefore, PM has great potential to mitigate Nr loss in China when crop species, N fertilization rate, and local environmental factors (i.e., growing region and annual precipitation) are appropriately considered., Competing Interests: Declaration of competing interest The authors have declared that no competing interests exist., (Copyright © 2020 Elsevier B.V. All rights reserved.)