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The current context of food security and global geopolitical crises calls for proactive efforts to seek adaptive strategies for limited resources in agriculture. The production of phosphatic-based fertilisers has caused a substantial depletion of natural phosphorus (P) reserves, raising concerns about price increases due to the growing demand for P. The aim of the study is to assess whether the use of liquid organo-mineral P-complexes can be an adaptive strategy to address the issue of the limited P-fertiliser resource. A complete randomised block design was implemented with three replicates, spanning two contrasting cropping seasons under a Mediterranean climate with reduced tillage and rainfed conditions. The study aimed to assess the response of a durum wheat–maize rotation to various rates of liquid organo-mineral P-complexes (humic-complexed phosphate; HCP) in comparison to granular triple superphosphate (TSP). The evaluation focused on several parameters, including P availability, plant architecture, dry matter accumulation, grain yield and yield components and P use efficiency (PUE) for both durum wheat and maize. The results revealed that applying HCP at a rate of 4 or 8 kg ha−1 increased soil P availability on average by 66% and 144%, respectively, compared to the control (no P-fertilisation), although a significant interaction with the monitoring year emerged. For wheat, applying HCP at a rate of 8 kg ha−1 of P resulted in higher grain yield (+15%), protein content (+0.9%) and P uptake (+48%) than the control on average considering both monitoring years. In the season characterised by favourable rainfall patterns, the application of HCP at 5 or 10 kg ha−1 of P for maize showed similar effects in terms of soil P availability, dry matter accumulation, grain yields and PUE. Conversely, in the season marked by a deficiency in summer precipitation, low PUE for maize was observed for HCP fertilisers, although they remained positive, unlike the case of TSP. Using HCP in conservation agriculture appears promising as an adaptive solution to address P-fertiliser scarcity, especially amid food security challenges and global crises. However, further studies are required to validate these findings in diverse pedo-climatic contexts and cropping systems. • Humic complexed P fertiliser (HCP) enhances soil P availability, especially at 0–10 cm depth. • HCP resulted in a general higher maize and wheat grain yield and crops P efficiency. • HCP is promising in the context of conservation agriculture. [ABSTRACT FROM AUTHOR]

Despite conservation agriculture (CA) is being promoted as a climate resilient technology, limited information is available on its impacts on N storage within soil aggregates vis a vis global warming potential (GWP) under tropical agro-ecosystems. Hence, this study assessed the effects of a medium-term (5-years) CA on total soil N (TSN) changes in bulk soils and aggregates, N 2 O and CO 2 emission, GWP and total C fixed in soils under maize ( Zea mays L.)- wheat ( Triticum aestivum L.) system on the Indo-Gangetic Plains (IGP). The treatments were: conventional tillage (CT), zero tillage (ZT) with planting on permanent narrow beds (PNB), PNB with residue (PNB + R), ZT with planting on permanent broad beds (PBB), PBB with residue (PBB + R), ZT on flat land/plains without crop residue (ZT) and with crop residue retention (ZR + R). Soil samples were collected after five years of a maize–wheat system and TSN in bulk soils and their aggregates of the 0–5 and 5–15 cm soil layers were measured along with N 2 O and CO 2 emissions during the fifth year (2014–15).The soils under PBB + Rhad 37 and 9% more macro-aggregate-and micro-aggregate-associated N concentrations in topsoil (0–5 cm layer) than CT (248 and 299 kg N ha −1 ). However, topsoil soil aggregation and aggregate-associated N contents of PNB + R and ZT + R were similar to CT plots. The dehydrogenase and fluorescein diacetate activities and TSN, microbial biomass N, NO 3 -N and NH 4 -N concentrations were also highest in PBB + R plots in topsoil. The topsoil dehydrogenase activity was significantly correlated (r = 0.426, n = 21, p < 0.05) with CO 2 emission and with N 2 O emission (r = 0.770, n = 21, P < 0.01) during wheat (2014–15). However, topsoil FDA activities and MBN concentrations were only significantly correlated with N 2 O emission in wheat. In the maize–wheat system, highest N 2 O emission was observed in PNB + R plots and least in CT plots. But, PBB + R and PNB + R plots had similar CO 2 emissions to CT plots in both crops. Despite GWP of ZT + R and PBB + R plots in the maize-wheat system were ∼5% higher than CT, greenhouse gas (GHG) intensities in the CT, PBB + R and ZT + R plots were similar. Thus, PBB + R practice is a better management alternative for soil N improvement (and a reduced fertilizer N dose could be adopted in future) than CT since this practice also had 36% and 8.2% higher biomass productivities of maize and wheat, respectively in the maize-wheat cropping system and similar GHG intensity to CT plots. [ABSTRACT FROM AUTHOR]

Two of the most important agricultural practices aimed at improving soil properties are crop rotations and no-tillage, yet relatively few studies have assessed their long-term impacts on crop yields and soil greenhouse gas (GHG) emissions. The objective of this study was to determine the influence of tillage and crop rotation on soil GHG emissions and yields following 15 years of treatment implementation in a long-term cropping systems experiment in Illinois, USA. The experimental design was a split-plot RCBD with crop rotation as the main plot: (continuous corn [ Zea mays L.] (CCC), corn-soybean [ Glycine max (L.) Merr.] (CS), continuous soybean (SSS), and corn-soybean-wheat [ Triticum aestivum L.] (CSW); with each phase of each crop rotation present every year) and tillage as the subplot: chisel tillage (T) and no-tillage (NT). Tillage increased the yields of corn and soybean. Tillage and crop rotation had no effect on methane (CH 4 ) emissions (p = 0.4738 and p = 0.8494 respectively) and only rotation had an effect on cumulative carbon dioxide (CO 2 ) (p = 0.0137). However, their interaction affected cumulative nitrous oxide (N 2 O) emissions significantly (p = 0.0960); N 2 O emissions from tilled CCC were the greatest at 6.9 kg-N ha −1 -yr −1 ; while emissions from NT CCC (4.0 kg-N ha −1 -yr −1 ) were not different than both T CS or NT CS (3.6 and 3.3 kg-N ha −1− yr −1 , respectively). Utilizing just a CS crop rotation increased corn yields by around 20% while reducing N 2 O emissions by around 35%; soybean yields were 7% greater and N 2 O emissions were not affected. Therefore results from this long-term study indicate that a CS rotation has the ability to increase yields and reduce GHG emissions compared to either CCC or SSS alone, yet moving to a CSW rotation did not further increase yields or reduce N 2 O emissions. [ABSTRACT FROM AUTHOR]

Soil CO 2 emissions respond differently to different tillage practices. However, limited information is available regarding the impact of conventional tillage (CT) and no-tillage (NT) on soil CO 2 emissions and the primary controlling factors or processes. The goal of this study is to derive the relationship of soil CO 2 emissions with soil physicochemical properties from differently tilled soils in a typical winter wheat summer maize rotation system. We hypothesized that soil tillage practices would impact the soil carbon cycle by modifying soil physical and chemical properties, which would in turn affect the soil CO 2 emissions. The study was conducted from 2018 to 2022 with two tillage practices using a randomized complete block design with three replicates. A leading international real-time monitoring system in situ was used to collect soil CO 2 emission data. Cumulative soil CO 2 emissions were reduced by 28.7% in maize and increased by 9.0% in wheat under NT as compared to CT. On an annual scale, the cumulative CO 2 emissions were decreased by 20.5% in NT as compared to CT. Maize season accounted for 70% 78% of soil CO 2 emissions. NT improved the aboveground biomass by 7.74% and 6.44%, and grain yields by 10.2% and 4.49% for maize and wheat, respectively. The soil CO 2 emission intensity of maize was reduced by 35.9% under NT as compared to CT. No significant differences were discovered under the two tillage practices for soil CO 2 emission intensity of wheat. For maize, NT increased the bulk density, subsequently decreasing soil temperature and increasing soil moisture. NT also led to higher soil organic carbon and total nitrogen content, ultimately resulting in a significant reduction in soil CO 2 emissions. For wheat, NT increased soil bulk density, further increasing soil moisture and lowering soil pH. NT thus resulted in lower soil organic carbon and total nitrogen content, ultimately leading to enhanced soil CO 2 emissions. Some of these observations might not be consistent with theoretical predictions, which indicated that the unconsidered factors of actual field conditions might have much significant effects. Overall, NT can be extensively used as an eco-friendly cropland tillage practice based on its positive effects of reducing CO 2 emissions and increasing crop yields. [Display omitted] • CO 2 emission variations by tillage were evaluated by the structural equation model. • No-tillage (NT) decreased CO 2 emissions by 28.7% in maize and increased by 8.99% in wheat. • Annual CO 2 emissions were decreased by 20.5% under NT than conventional tillage (CT). • Maize season accounted for 70% 78% of soil CO 2 emissions. • CO 2 emission intensity of maize was reduced by 35.9% under NT compared with CT. [ABSTRACT FROM AUTHOR]

Winter wheat ( Triticum aestivum L.)-fallow (WF) remains a prominent cropping system throughout the Central Great Plains despite documentation confirming the inefficiency of precipitation storage during the summer fallow period. Wheat yield is greatly influenced by available soil water at planting, and that quantity is influenced by cropping intensity, tillage intensity, crop grown prior to winter wheat planting, and length of the non-crop period prior to winter wheat planting. The objective of this study was to determine the effect of cropping system intensity, tillage, and crop prior to wheat planting on available soil water at planting and the probabilities of having certain minimum amounts of available soil water at wheat planting. Available soil water was measured at wheat planting for nine cropping systems varying in fallow frequency, tillage intensity, and crop prior to wheat over a 25-yr period at Akron, CO. Available soil water at wheat planting was found to be greatest (average 218 mm) for no-tillage (NT) and reduced-tillage (RT) systems in which a fallow period of 12–14 months preceded wheat planting. The lowest amounts of available soil water at wheat planting were found for the continuously cropped rotations (average 100 mm). The cumulative probability exceedance graphs of available soil water at planting fell into three groupings: 1) the five rotations that had a NT or RT fallow period prior to the next wheat crop; 2) the WF (conventional till) rotation; 3) the three rotations with either pea ( Pisum sativum L.) or proso millet ( Panicum miliaceum L.) prior to the next wheat crop. These graphs provide a valuable decision support tool for helping farmers assess risk in moving from a WF cropping system to a system of greater cropping intensity and diversity. [ABSTRACT FROM AUTHOR]

The Indo-Gangetic Plains (IGP) of India is dominated with rice − wheat cropping system that occupies almost 10.5 million ha area. The sustainability of rice-wheat system is under threat due to numerous water-, nutrients-, weeds- and environment-related problems, mainly, due to the cultivation of rice. Suitable crop and soil management practices with a bias to conservation agriculture (CA) that can sustain soil and environmental health as well as improve crop and water productivity, are required for the Indian IGP. Maize can be a viable alternative to rice and a potential driver for diversification of rice-wheat system. The acreage of maize is on the increase in conventional and conservation agriculture-based cereal systems of India in recent years. Therefore, a field experiment, involving a maize ( Zea mays L.)-wheat cropping system was undertaken on a sandy clay loam soil for three years (2010–11 to 2012-13) in New Delhi to evaluate the impacts of CA on crop and water productivity, profitability and soil organic carbon (SOC) accumulation. There were five CA-based treatments in first year, and two treatments were introduced in second year (2011-12) onwards. The experiment was laid out in a randomized complete block design with three replications. In all the residue retention plots, wheat residue was retained in maize crop and maize residue was retained in wheat crop under zero till conditions. Results showed that the plots under permanent broad bed with residue (PBB + R) and without residue (PBB) resulted in ∼29 and ∼26% higher maize grain yield, respectively than conventional tillage (CT) (2.6 t ha −1 ), but wheat grain yields were comparable in all the treatments in first year. Maize grain yield in second year under PBB + R and zero tillage with residue (ZT + R) were 55 and 43% higher than CT plots (2.8 t ha −1 ). Three-year mean maize yields due to PBB + R and permanent narrow bed with residue (PNB + R) were 28 and 15% higher than that in CT plots (3.3 t ha −1 ). The PBB + R resulted in 11% higher two-year mean water productivity in maize than PBB (∼without residue), but both these treatments were comparable in this regard in wheat. The ZT + R plots resulted in 14% and 22% higher two-year mean water productivity, respectively in maize and wheat than ZT plots. Overall, the plots under PBB + R had 57% and 19% higher mean water productivities in maize and wheat, respectively compared with CT plots. Again, the PBB + R plots gave 12% higher two-year mean net returns compared with CT plots. With regard to net returns, the plots under permanent narrow bed with and without residue (PNB + R; PNB) were inferior to PBB, PBB + R, ZT and ZT + R plots. Retention of both-season crop residues could significantly improve SOC concentration in surface (0–5 cm) soil. The PBB + R resulted in highest SOC pool at 0–30 cm soil layer, which was significantly higher than that in CT. This system showed maximum carbon sequestration potential. Thus, this CA practice, which involves PBB + R is superior to other practice. This would save water through higher water-use efficiency, and lead to accumulation of more carbon in soil with higher sequestration potential, besides giving sustainable production through maize-wheat system over the years. This can be adopted across the IGP regions of India, where irrigated rice-wheat system is in practice, and in similar agro-ecologies of the tropics and sub-tropics under irrigated conditions. [ABSTRACT FROM AUTHOR]

Tillage practice can change soil properties, regulate crop root development and nutrient availability, thus affecting crop growth and yield. However, the effect of no tillage (NT) and deep tillage (DT) on crop yield relative to conventional tillage (CT) under varied environmental and management conditions is unclear in China. We assessed the yield response of wheat and maize to NT and DT relative to CT based on collected field data (518 observations) with a meta-analysis. In general, NT led to negative yield response of both crops relative to CT, whereas maize presented a positive yield response (6.0 %) to NT in sandy soil, and crop yield responses to NT were not significantly different among environmental and management factors. DT significantly increased the yield of wheat (8.7 %) and maize (8.2 %) over CT. For wheat, the yield response to DT was similar across soil textures, climate conditions, experiment durations, N fertilizer rates, and residue managements; however, the interval DT every 2–3 years (13.2 %) and monoculture (13.9 %) increased yield response than the continuous DT (8.4 %) and double cropping system (8.9 %), respectively. The yield response of maize to DT was greater in semidry region (16.1 %) and under high N fertilizer rate (>300 kg N ha−1) (16.1 %), interval DT (12.4 %) compared with those in humid (7.5 %) and semi-humid (6.8 %) regions, low N fertilizer rates (<300 kg N ha−1) (6.9 %−7.5 %), and continuous DT (7.8 %), respectively; but other environmental and management factors did not affect its yield response. Overall, NT presented similar yield of wheat and maize to CT, while DT significantly enhanced their yields; this analysis revealed the crucial environmental and management factors influencing yield response to tillage practices in China, we also gave some suggestions on selecting appropriate tillage methods to realize high crop yield or/and agricultural sustainable development. • NT led to negative yield response of wheat and maize relative to CT. • DT significantly enhanced wheat and maize yields over CT. • Interval DT and monoculture presented better effects on crop yield response to DT. • Environmental and management factors should be considered to enhance yield using DT. [ABSTRACT FROM AUTHOR]

Intensive rice (Oryza sativa)-based cropping systems in south Asia provide much of the calorie and protein requirements of low to middle-income rural and urban populations. Intensive tillage practices demand more resources, damage soil quality, and reduce crop yields and profit margins. Crop diversification along with conservation agriculture (CA)-based management practices may reduce external input use, improve resource-use efficiency, and increase the productivity and profitability of intensive cropping systems. A field study was conducted on loamy soil in a sub-tropical climate in northern Bangladesh to evaluate the effects of three tillage options and six rice-based cropping sequences on grain, calorie, and protein yields and gross margins (GM) for different crops and cropping sequences. The three tillage options were: (1) conservation agriculture (CA) with all crops in sequences untilled, (2) alternating tillage (AT) with the monsoon season rice crop tilled but winter season crops untilled, and (3) conventional tillage (CT) with all crops in sequences tilled. The six cropping sequences were: rice-rice (R-R), rice-mung bean (Vigna radiata) (R-MB), rice-wheat (Triticum aestivum) (R-W), rice-maize (Zea mays) (R-M), rice-wheat-mung bean (R-W-MB), and rice-maize-mung bean (R-M-MB). Over three years of experimentation, the average monsoon rice yield was 8% lower for CA than CT, but the average winter crops yield was 13% higher for CA than CT. Systems rice equivalent yield (SREY) and systems calorie and protein yields were about 5%, 3% and 6%, respectively, higher under CA than CT; additionally, AT added approximately 1% more to these benefits. The systems productivity gain under CA and AT resulted in higher GM by 16% while reducing the labor and total production cost under CA than CT. The R-M rotation had higher SREY, calorie, protein yields, and GM by 24%, 26%, 66%, and 148%, respectively, than the predominantly practiced R-R rotation. The R-W-MB rotation had the highest SREY (30%) and second highest (118%) GM. Considering the combined effect of tillage and cropping system, CA with R-M rotation showed superior performance in terms of SREY, protein yield, and GM. The distribution of labor use and GM across rotations was grouped into four categories: R-W in low-low (low labor use and low GM), R-M in low-high (low labor use and high GM), R-W-MB and R-M-MB in high-high (high labor use and high GM) and R-R and R-MB in high-low (high labor use and low GM). In conclusion, CA performed better than CT in different winter crops and cropping systems but not in monsoon rice. Our results demonstrate the multiple benefits of partial and full CA-based tillage practices employed with appropriate crop diversification to achieve sustainable food security with greater calorie and protein intake while maximizing farm profitability of intensive rice-based rotational systems. • Rice-maize (R-M) outperformed over all other rice-based cropping systems considering yields and profits. • Conservation agriculture (CA) and alternate tillage (AT) outperformed than conventional tillage (CT). • R-M and rice-wheat-mungbean systems are more beneficial when layered with CA and AT. • Rice-rice system is more labor intensive and less profitable than other systems. • CA is good for winter crops and for cropping systems but not for rice but AT can be viable alternative option. [ABSTRACT FROM AUTHOR]

The increasing demand for high-quality animal protein calls for parts of cereal cropping systems converting to forage or forage-livestock integrated systems. This study aimed at evaluating potential environmental impacts of this transition at the farm level on the Loess Plateau of China through a life cycle assessment (LCA) approach. Four dominating crops: alfalfa, wheat, grain maize and silage maize were studied based on the ten impact categories. Based on standard unit land area (1 ha) and timestamp (2018–2020) settings, alfalfa production indicated the lowest environmental impact in nine categories compared to other crops, while wheat indicated better performance in seven of ten impact categories than other crops except alfalfa. With respect to the environmental loads of grain maize and silage maize production, both systems were very comparable. Because of the common adoption of open-land burning of straws (mainly for fuel and winter heating) in the local region, the respiratory inorganics and photochemical oxidant formation potential impact of alfalfa and silage maize per hectare produced is much lower than those of wheat and grain maize. Great differences in environmental impacts between the two types of cropping systems (cereal vs forage) indicate that transitioning from cereal to forage production should effectively reduce air pollution and enhance environmental sustainability on the Loess Plateau. Besides, uncertainty and variability of LCAs results were analyzed in this study. [Display omitted] • Environmental impacts of four types of cropping systems were compared by land unit. • Impact variability among farms was analyzed through 607 LCAs. • Performance of most impact categories was alfalfa>wheat>silage maize>grain maize. • Forage cropping systems incurred less air pollution than cereal systems. [ABSTRACT FROM AUTHOR]

The increasing demand for high-quality animal protein calls for parts of cereal cropping systems converting to forage or forage-livestock integrated systems. This study aimed at evaluating potential environmental impacts of this transition at the farm level on the Loess Plateau of China through a life cycle assessment (LCA) approach. Four dominating crops: alfalfa, wheat, grain maize and silage maize were studied based on the ten impact categories. Based on standard unit land area (1 ha) and timestamp (2018–2020) settings, alfalfa production indicated the lowest environmental impact in nine categories compared to other crops, while wheat indicated better performance in seven of ten impact categories than other crops except alfalfa. With respect to the environmental loads of grain maize and silage maize production, both systems were very comparable. Because of the common adoption of open-land burning of straws (mainly for fuel and winter heating) in the local region, the respiratory inorganics and photochemical oxidant formation potential impact of alfalfa and silage maize per hectare produced is much lower than those of wheat and grain maize. Great differences in environmental impacts between the two types of cropping systems (cereal vs forage) indicate that transitioning from cereal to forage production should effectively reduce air pollution and enhance environmental sustainability on the Loess Plateau. Besides, uncertainty and variability of LCAs results were analyzed in this study. [Display omitted] • Environmental impacts of four types of cropping systems were compared by land unit. • Impact variability among farms was analyzed through 607 LCAs. • Performance of most impact categories was alfalfa>wheat>silage maize>grain maize. • Forage cropping systems incurred less air pollution than cereal systems. [ABSTRACT FROM AUTHOR]

The carbon management index (CMI) and labile organic carbon (LOC) pools are postulated as very sensitive indicators of changes in soil organic carbon (SOC) due to land degradation within a short time in response to management practices. To test this hypothesis, we investigated LOC and CMI under a field experiment (2007–2013) in relation to runoff, soil loss, maize and wheat yields on a 2% (1.15°) land slope of the Indian Himalayas. In this study, the impacts of several resource conservation practices, including different combinations of vegetative barriers (VB), minimum tillage (MT), different organic amendments (OA) and weed mulch, were evaluated. Results revealed that the plots under MT + OA with three applications of weed mulch had more SOC, macroaggregate-associated C concentrations and macroaggregates than conventional tillage (CT) + NPK with chemical weed control. Carbon management index varied from 47 to 59 and 42 to 55% with different conservation practices at depths of 0–5 and 5–15 cm depths, respectively. Incorporation of weed mulch along with application of OM, MT and VB (by Palmarosa ) under MT improved CMI by 19.7 and 24.2% compared to CT plots with VB (by Panicum ) and inorganic NPK at depths of 0–5 and 5–15 cm, respectively. Significant positive correlations were observed between CMI and maize yield ( r = 0.948; n = 24; P < 0.01), CMI and wheat yield ( r = 0.872; n = 24; P < 0.01) and CMI and wheat equivalent yield ( r = 0.906; n = 24; P < 0.01). However, significant negative correlations were obtained for CMI and runoff ( r = −0.701; n = 20; P < 0.01) and CMI and soil loss ( r = −0.768; n = 20; P < 0.01). Results established that Palmarosa as VB along with OA plus weed-mulch under MT was the best management practice for decreasing runoff and soil loss and increasing system productivity on a 2% slope in the region. The single value CMI was strongly positively correlated with crop productivity and negatively correlated with soil loss. Hence, this single value CMI could potentially be used for assessment of soil degradation elsewhere. [ABSTRACT FROM AUTHOR]

This study aimed to identify whether nitrogen (N) use efficiency in a summer-maize/winter-wheat double-cropping system of the North China Plain (NCP) could be increased by adjusting N supply to crop N demand, and through the use of alternate N fertilizers and application strategies. In a static experiment conducted on a farmers’ field six reduced N treatments were compared to farmers’ practice (FP: 550 kg (N) ha −1 a −1 ) and a control treatment (CK). With few exceptions of single treatments in single cropping-seasons, the optimized fertilization of N did not lead to a yield reduction of either summer-maize or winter-wheat. The grain yield of summer-maize ranged between 5.8 and 7.1 Mg ha −1 . The grain yield of wheat ranged between 4.4 and 6.2 Mg ha −1 . For the first two vegetation periods of summer-maize, the recovery efficiency (RE N : 0.09–0.30 kg kg −1 ) and agronomic efficiency of N (AE N ) were mainly affected by the yield achieved in the control treatment (5.7 and 5.9 Mg ha −1 ), which was not significantly reduced compared to most fertilized treatments. In the third vegetation period of summer-maize, an increase of RE N of the reduced treatments (0.37–0.58 kg kg −1 ) was determined compared to FP (0.21 kg kg −1 ). In both vegetation periods of wheat RE N of the reduced treatments (0.34–1.0 kg kg −1 ) was significantly higher compared to FP (0.26 and 0.27 kg kg −1 ). The highest cumulated AE N , as well as cumulated grain yields were observed when ammonium sulphate nitrate + 3,4-dimethylpyrazolephosphate (ASN DMPP ) was applied according to crop N demand and residual soil mineral N. The highest RE N was observed when urea ammonium nitrate was applied in a shallow, banded depot (UAN DEP ). This research demonstrates that N application rates in a maize/wheat double cropping system may be significantly reduced compared to common farmers’ practice, without negatively affecting grain yield, thereby increasing N use efficiency. [ABSTRACT FROM AUTHOR]

Highlights: [•] RZ-SHAW model simulated actual evapotranspiration (AET) well as compared to latent heat fluxes obtained from the eddy covariance measurement. [•] RZ-SHAW model also simulated potential evapotranspiration (PET) well as compared to PET from weighing lysimeter. [•] Canopy temperature is well simulated with the RZ-SHAW model, which may be used as an index for crop water stresses. [Copyright &y& Elsevier]

[Display omitted] • Nutrient Expert (NE), is designed through adoption of 4R nutrient stewardship. • Results show that NE achieved higher yields, higher profitability, and lower environmental risks. • An outstanding advantage of NE is user-friendly and can be easily acquired by all farmers with smartphones. Fertilizer has revolutionized crop production, but a lack of evidence-based fertilizer usage has resulted in negative economic and environmental ramifications, particularly for smallholder farmers. This study aimed at developing an innovative nutrient recommendation approach, Nutrient Expert (NE), for improving yields of maize, wheat, and rice while optimizing fertilizer input through adoption of 4R (applying the right source of nutrients at the right rate, time and place) nutrient stewardship technologies, and evaluating the large-scale performance on crop productivity and the environmental impact of cropping systems. Thus, we compared NE to current farmers' practice (FP) and soil test-based fertilizer application (ST) for 1,534 farm field experiments in order to validate the benefits of NE on both crop productivity and environmental protection in the main cereal production areas in China. Overall, the NE treatment achieved 4.4 % higher grain yield and 5.8 % more profit over FP, more yield for rice, but no differences for maize and wheat over ST. Nutrient Expert required 29.0 % and 14.7 % less fertilizer N than FP and ST, respectively. The NE recommendations improved the nitrogen (N) recovery efficiency by 10.8–13.4 percent points over FP across the 1,534 sites. Using the NE approach, on average, reactive N losses and greenhouse gas (GHG) emissions were reduced by 36.2 % and 21.5 % over FP, 16.0 % and 9.9 % over ST, respectively. The NE, as a user-friendly tool, is widely applicable across farm types and climatic regions. It could be beneficial for improving fertilizer use efficiency and maintaining strategic food security for smallholder production areas in China where N fertilizer is inappropriate and usually over applied. This approach could potentially be expanded to help reduce N losses and GHG emissions in other regions globally. [ABSTRACT FROM AUTHOR]

Highlights: [•] Adjusting fertilization to the crop requirements reduces the N balance in a farmer's field. [•] N mineralized in spring is only utilized by the following summer-crop. [•] N application above crop requirements increases the amount of cycling N and apparent N loss. [Copyright &y& Elsevier]

Highlights: [•] The summer crop of maize was the main contributor to annual N2O emissions. [•] DMPP urea was effective in reducing N2O emissions only in the maize season. [•] Applying DMPP urea did not increase yields. [•] Adjusting N fertiliser rates on estimated residual soil N reduced N2O emissions. [•] Severe yield loss can occur if residual soil N is not estimated correctly. [ABSTRACT FROM AUTHOR]

Highlights: [•] Corn and pea ahead of wheat did not increase wheat WUE in the central Great Plains, USA. [•] Corn ahead of proso millet did not increase proso millet WUE. [•] Dryland wheat yield was not increased with corn included in a rotation. [•] Growing pea ahead of wheat decreased wheat yield. [•] Growing corn ahead of proso millet decreased millet yield. [ABSTRACT FROM AUTHOR]

[Display omitted] • WEY increased from 56.92 to 315.42 % in 100 % N under bi cropping system. • Net returns increased from US $ 188.5 to US $ 224.0/ha in 100 % N in bi-cropping system. • Soil OC, available N and P increased significantly in bi-cropping system. • 100 % N application in bi-cropping had highest stability in wheat equivalent yield. • Bi-cropping system recorded higher LER (18.01 to 57.65 %) over sole cropping. We studied the integration of white clover (Trifolium repens) with nitrogen management practices in wheat (Triticum aestivum L.) - maize (Zea mays L.) cropping sequence to find optimum level of N and to enhance forage production. This experiment was laid out in Randomized Block Design with three replications comprising of 12 treatments viz., (T 1) wheat-maize; (T 2) white clover + wheat -maize (0 N); (T 3) white clover (sole); and (T 4 to T 12) 50, 75 and 100 % of recommended N to wheat, maize or both. Application of 100 % N to white clover + wheat - maize (bi-cropping) recorded the highest crude protein in white clover. Wheat equivalent yield (WEY) was computed by multiplying the white clover and maize yields with their respective per unit price to compare the system productivity. The system productivity was found 2.67 (56.92 %) and 5.93 t/ha (315.42 %) higher in 100 % N application to bi-cropping over wheat-maize (0 N) and sole white clover, respectively. Highest net returns (US $ 188.5 and 224.0/ha at farmers' field and research farm, respectively) were also recorded in the same bi-cropping treatment. Bi-cropping along with N application resulted in higher Land equivalent ratio (LER) (18.01–57.65%) over sole cropping. The treatment and treatment x environment (TTE) bi-plot also explained 99.84, 98.70 and 99.63 % of treatment and treatment × environment variation for WEY, Benefit: Cost Ratio (BCR) and LER, respectively. Soil fertility improved significantly in sole white clover and bi-cropping treatments with N application. However, when upto 75 % N of recommended dose of fertilizers (RDF) was applied to bi-cropping system resulted in higher WEY, BCR and LER, which were at par with 100 % N. Thus, cereal-clover bi-cropping system along with 75 % N of RDF can be recommended for sustainable forage and food production; and better soil health in temperate, sub-temperate climatic regions of the world. [ABSTRACT FROM AUTHOR]

Abstract: Understanding soil organic carbon (SOC) decomposition and its replenishment by contrasting plant residues is critical to rationally manage soil carbon pools. Long-term (15years) field experiments in maize–wheat (Zea mays L.–Triticum aestivum L.) rotation systems at diverse sites with contrasting climates and soil properties were conducted to evaluate the temporal dynamics of the C inputs, SOC concentrations and δ13C values. In the non-fertilized Control treatments mean annual C inputs (mainly roots) at the various sites ranged from 0.39 to 1.24Mgha−1, and SOC contents remained largely unchanged during the 15years study. However, results for the fertilized treatments indicated that SOC concentration increased by 1gkg−1 for every 24.3 (5.4–45.2) MgCha−1 from roots alone in the NPK treatment and for every 29.4 (11.1–52.6) MgCha−1 from crop roots plus straws in the NPKSt treatment. Furthermore, there was a positive correlation among changes in SOC, C4-derived C and C3-derived C and the δ13C values in all treatments across the four sites. Our results suggest that the δ13C value was a useful tool to quantify temporal changes of SOC from C4 and C3 plants, even when actual changes in soil C stock were small in these wheat–maize rotation cropping systems. [Copyright &y& Elsevier]

Abstract: A process-based ecosystem model (Vegetation–atmosphere Interface Processes (VIP) model) is expanded, and then validated against three years’ biometric, soil moisture and eddy-covariance fluxes data over a winter wheat–summer maize cropping system in the North China Plain (NCP). The results show that the model is capable of simulating satisfactorily the evolution of crop biomass, phenological development and soil moisture. The computed 30-min estimates of CO2, water and heat fluxes agree well with the eddy-covariance measurements. At daily scale, the root mean square errors (RMSEs) of net radiation, latent heat flux and net ecosystem productivity (NEP) are 1.0MJm−2 day−1, 1.8MJm−2 day−1 and 2.6gCm−2 day−1, respectively. However, systematic errors in sensible heat flux estimates are identified in times of season when daily sensible heat flux is negative due to the horizontal advection. Annually, about 55% of evapotranspiration (ET) is emanated from winter wheat and 45% from maize. The annual NEP varies noticeably, with relative biases of 18, 9 and −29% in each year from 2003 to 2005, respectively. Sensitivity analysis illustrates that ET is quite sensitive to soil resistance parameters contributing to soil evaporation, and NEP to quantum efficiency of photosynthesis. The uncertainties of annual ET and NEP are 16.5% and 35.6% respectively when the key parameters are randomly sampled in their uncertainty ranges. Errors on eddy-covariance measurements and uncertainty on the model parameters may partly explain the discrepancy between the simulations and the measurements. [Copyright &y& Elsevier]

Abstract: Nitrogen amendment followed by flooding irrigation is a general management practice for a wheat–maize rotation in the North China Plain, which may favor nitrification and denitrification. Consequently, high emissions of nitrous oxide (N2O) and nitric oxide (NO) are hypothesized to occur. To test this hypothesis, we performed year-round field measurements of N2O and NO fluxes from irrigated wheat–maize fields on a calcareous soil applied with all crop residues using a static, opaque chamber measuring system. To interpret the field data, laboratory experiments using intact soil cores with added carbon (glucose) and nitrogen (nitrate, ammonium) substrates were performed. Our field measurements showed that pulse emissions after fertilization and irrigation/rainfall contributed to 73% and 88% of the annual N2O and NO emissions, respectively. Soil moisture and mineral nitrogen contents significantly affected the emissions of both gases. Annual emissions from fields fertilized at the conventional rate (600 kg N ha−1 yr−1) totaled 4.0 ± 0.2 and 3.0 ± 0.2 kg N ha−1 yr−1 for N2O and NO, respectively, while those from unfertilized fields were much lower (0.5 ± 0.02 kg N ha−1 yr−1 and 0.4 ± 0.05 kg N ha−1 yr−1, respectively). Direct emission factors (EFds) of N2O and NO for the fertilizer nitrogen were estimated to be 0.59 ± 0.04% and 0.44 ± 0.04%, respectively. By summarizing the results of our study and others, we recommended specific EFds (N2O: 0.54 ± 0.09%; NO: 0.45 ± 0.04%) for estimating emissions from irrigated croplands on calcareous soils with organic carbon ranging from 5 to 16 g kg−1. Nitrification dominated the processes driving the emissions of both gases following fertilization. It was evident that insufficient available carbon limited microbial denitrification and thus N2O emission. This implicates that efforts to enhance carbon sink in calcareous soils likely increase their N2O emissions. [Copyright &y& Elsevier]

Abstract: Wheat–maize double cropping is the most important cropping system on the Hebei Plain and is one of the most important cropping systems in China. In a scenario of greater food demand, and increasing water and rural labour scarcity, it is critical that the annual productivity of the system is improved in water-energy-cost efficient and low carbon ways. Based on farm surveys, this paper benchmarked the performance of wheat–maize double crops on the Hebei Plain during the 2004–2005 season. These farm yields were assessed both against experimental yields collected from on-farm maximum yield trials conducted during the same 2004–2005 season and relative to simulated estimates of the climate-driven potential productivity of the region. The survey of 362 farms in six counties of the Hebei Plain during the 2004–2005 season found wheat yields ranging from 3375kgha−1 to 9000kgha−1 with an overall average yield of 6556kgha−1. Maize yields averaged 7549kgha−1 and ranged from 3375kgha−1 to 11,250kgha−1. The aggregate production for the wheat–maize double crops grown in the 2004–2005 season averaged 14,105kgha−1 across the six counties. This was 72% of the average production (19,586kgha−1) recorded from on-farm trials conducted in each of the six counties and 60% of the simulated average production potential (24,147kgha−1) for the Hebei Plain in the 2004–2005 season. Thus, the annual productivity of the current cropping system could be increased with currently available technologies by 28%, while a yield increase of 42% is possible if farm yields approach the simulated yield potential. Based on farmer interviews and field observations, a number of real and perceived reasons for the current yield gaps in farmers’ fields were recognised. For instance, irrigation at stem-elongation of wheat is a current recommendation, yet only a proportion of the surveyed farmers were able to follow this strategy due to lack of access to shared irrigation facilities. Improving the region''s infrastructure to enable more timely irrigation of crops will be a necessary prerequisite to improved productivity. The results from the farm surveys and on-farm trials indicate that, with current recommended practices, farmers can improve their annual farm productivity and close the current yield gaps. However, the survey identified that increasing system performance and efficiency will require a focus on both agronomic and socio-economic issues. [Copyright &y& Elsevier]

Abstract: Intensively cropped agricultural production systems should be managed to improve soil quality and ecological processes and ultimately strengthen system capacity for sustained biological productivity. We examined the long-term changes (>20 years) in soil quality and productivity with incorporation of ecological management principles in a set of intensively managed row crop systems of the upper Midwest, USA. Replicated experimental treatments include corn (maize)–soybean–wheat cropping systems under four different management regimes: (a) conventional tillage and fertilizer/chemical inputs (Conventional), (b) no tillage with conventional fertilizer/chemical inputs (No-till), (c) conventional tillage with ∼30% of conventional fertilizer/chemical inputs and a leguminous cover crop (Reduced Input), and (d) conventional tillage with no fertilizer/chemical input and a leguminous cover crop (Organic). Effects of these treatments on soils were compared by developing a soil quality index (SQI) from 19 selected soil health indicators. An old field community maintained in early succession provided a benchmark for comparison. Reduction in tillage or fertilizer (No-till, Reduced Input and Organic) resulted in increased SQI and improved crop production. The No-till (SQI=1.02) and Reduced Input (SQI=1.01) systems outperformed Conventional management (SQI=0.92) in nitrogen availability and use efficiency, soil stability and structure improvement, and microbial nitrogen processing. Improvements in soil quality corresponded with increased primary production and crop yield in these systems, illustrating the value of an ecologically defined SQI for assessing the long-term effects of fertility and tillage management regimes in agricultural production systems. [Copyright &y& Elsevier]

Abstract: Efficiency of fertilizer N is becoming increasingly important in modern agricultural production owing to increasing food requirement and growing concern about environments. However, there is almost no study regarding its long-term efficiency in wheat and maize cropping systems. Long-term (15 years) experiments involving wheat (Triticum aestivum L.) and maize (Zea mays L.) rotations at five field sites with various soil and climate characteristics in China were used to determine the nitrogen (N) efficiency, including the physiological efficiency, recovery efficiency and N mass balance of soil–plant systems in response to different fertilization treatments. The present study consisted of nine treatments: unfertilized, N, phosphorus, potassium, straw and manure or their combinations. The contribution of N fertilizers to wheat yield was higher than to maize and suggested that wheat could be given priority over maize when determining N application rates. Uptake of 1kg N produced 35.6kg of wheat grain and 39.5kg of maize grain. The deficit of N in soils without applied N ranged from 40 to 103kgNha−1 year−1, while N surpluses in soils with applied N fertilizers ranged from 35 to 350kgNha−1 year−1. The apparent accumulated N recovery efficiency (NREac) varied widely from 4% to 90%: unbalanced fertilization and other soil limiting factors (such as aluminium toxicity) were associated with low NREac. In the treatments of combination of N, phosphorus and potassium with normal application rates, the average of NREac in four out of five sites reached 80%, which suggested that best management of N fertilizers could recover most of N fertilizers applied to soils. The results will be helpful to understand the long-term fate of N fertilizers and to optimize the N fertilization for agricultural practices and environment protection. [Copyright &y& Elsevier]

Abstract: Net carbon dioxide ecosystem exchange (NEE) was measured over three years (2006–2008) in a maize/faba/spring-wheat crop rotation in the Red River Valley of southern Manitoba, Canada using the flux-gradient method. The turbulent transfer coefficients were obtained using a similarity-theory, eddy-covariance based aerodynamic method and the carbon dioxide vertical gradient was measured with a tunable diode laser analyzer. The system measured 30-min-average fluxes over each of four plots sequentially to test reduced and intensive tillage treatments. Annual cumulative NEE was −720, 70 and −2400kgCha−1 yr−1 in the maize, faba and spring-wheat crop years, respectively. Enhanced respiration in the faba year was largely responsible for the loss, whereas the large gain in the spring-wheat year was a combination of high photosynthetic activity and reduced respiration. The three years experienced sequentially cooler and wetter years that likely affected the crops. After accounting for harvest removals, the net ecosystem loss was 510, 3140 and −480(gain)kgCha−1 yr−1 for the respective crop years, summing to a three-year loss of 3170kgCha−1. A recent conversion from intensive tillage to a reduced tillage practice showed no difference because of relatively large variability among the four plots. [Copyright &y& Elsevier]

Abstract: In the present study, water and nitrogen interaction on soil profile water extraction and evapo-transpiration (ET) was investigated taking a field experiment on a clay loam soil (Typic Haplustept) at the Indian Agricultural Research Institute, New Delhi with four consecutive crops (maize–wheat–maize–wheat) taken from July 2002 to April 2004. Three levels of water regime, namely W1, W2 and W3 referring to limited, medium and maximum irrigation were applied to each crop depending on the seasonal rainfall and the critical crop growth stage. The three water regimes were used with five nitrogen levels from T1 to T5, (T1, 0% N; T2, 75% N; T3, 100% N; T4, 150% N; T5, 100% N from organic source) in a split plot design for the four crops grown in sequence. Significant water and nitrogen interaction was observed for ET and soil profile water extraction pattern. Averaged across nitrogen treatments, ET in W2 and W3 were higher by 17 and 26%, respectively than W1 in maize 2002 and by 12 and 19% in maize 2003. In case of wheat, ET in W2 and W3 were higher by 27 and 58% than W1 in 1st crop and by 37 and 70% in 2nd crop. The effect of nitrogen regime, however, was prominent in both crops of maize and wheat, with significantly higher profile soil moisture depletion in T4 of each water regime. In all cases, lowest water depletion was observed in control plots receiving 0% N. In both crops, water extraction from surface 60cm was highest in W3 followed by W2 and W1. In maize, the % extraction from 0 to 60cm layer varied from 71 to 76% (W1), 70–79% (W2) and 75–82% (W3), whereas the values for wheat were 70–77, 72–79 and 75–83% for W1, W2 and W3, respectively. The 90–120cm layer contributed only 3–14% to total water extraction in both the crops. From 90 to 120cm layer, higher extraction was observed in W1 as compared to W3. The extraction values in W1, W2 and W3 in maize were 9–13, 7–14 and 3–9, respectively, whereas the corresponding values in wheat were 8–14, 5–12 and 3–7% for the three water regimes. Effect of nitrogen treatments on water extraction from deeper layer was observed with higher extraction in highest fertilized treatment (T4) as compared to other treatments. [Copyright &y& Elsevier]

Laser land levelling is expanding rapidly in the rice-wheat (RW) and maize-wheat (MW) systems of the Indo-Gangetic Plains of India and Pakistan. Current practice is to level to zero (0%) gradient, whereas a small gradient (e.g. 0.1%) is typically used in developed countries. Therefore, experiments were conducted in farmers' plots (~15 m x 40 m) in the Eastern Gangetic Plains to evaluate laser levelling with a 0.1% gradient in comparison with 0% and farmer levelling practice (FL). The study was conducted over two years in RW and MW systems. In the MW system, raised beds in plots lasered with 0% and 0.1% gradients were also evaluated. Laser levelling with 0% gradient significantly reduced irrigation amount and/or increased irrigation water productivity (WPi) in all crops/systems grown on the flat compared to FL except for wheat in the MW system. While there was a consistent trend for higher yield with a 0% gradient compared with FL, the differences were not significant in any crop/system. For the RW system, the results suggest no to marginal benefits in irrigation amount and WPi from levelling with a 0.1% gradient in comparison with 0% gradient. In that system, by far the bigger gains were from changing from FL to laser levelling with 0% gradient. This resulted in substantial reductions in irrigation amount, which greatly increased WPi in both crops (by ~40%), while yield was not affected. Rice grown with FL was not profitable, but lasering with 0% gradient significantly increased gross margin for rice, wheat and the total RW system. As for the RW system, levelling to 0% with a flat configuration significantly increased WPi of both crops in the MW system compared to FL, but by a lesser proportion. Raised beds significantly increased yield of maize by 8% (0.5 t ha−1), reduced irrigation amount by 20% (40 mm) and increased WPi by 34% (1.0 kg m−3) in comparison with the laser levelled flat plots. Gross margin of the MW system on beds was 17–20% higher than FL, and gross margin with beds on a 0.1% gradient was significantly higher than either gradient on the flat. The results suggest that the gains from levelling with a 0.1% gradient compared to 0% are marginal; however, this may change if the goal of consolidation of small farmer plots into larger fields becomes a reality provided there is a proportionate increase in irrigation flow rates, and ability to drain. • Land gradient (0, 0.1%) and configuration (flats, beds) were tested in non-puddled rice-wheat (RW) and maize-wheat (MW) systems. • 0% gradient with flat configuration did not increase yield but increased gross margin of RW system than farmer practice. • 0.1% gradient with flats increased yield, WPi and gross margin of all crops compared with farmer levelling. • In MW, beds increased WPi of maize over flats with the same gradient, and had the highest gross margin regardless of gradient. • Gross margin of the MW system was 2–4 times that of the RW system. [ABSTRACT FROM AUTHOR]

• A water-energy-food relative index for cropping systems at the field scale is proposed. • Synergy among water, energy and food in the North China Plain is evaluated. • Sustainable systems can balance crop production while reducing resource depletion. Extreme climate change, rapid population growth and economic development drive a growing demand for resources, which lead to energy, food, water and their intertwined nexus becoming increasingly important. Agricultural decisions considering the interconnections among water, energy, and food are critical. The consumption of large amounts groundwater and non-renewable energy by the predominant traditional wheat-maize cropping system has caused a serious water shortage in the North China Plain (NCP), which is a large food production region in China. This situation has strained the relationship between water/energy consumption and food production. It is important to seek synergy in the water-energy-food nexus. This paper proposed a relative index of water-energy-food (WEF RI) based on different values of resource consumption and use efficiency between treatment systems and control system to analyze the synergy between water utilization, energy consumption and food supply in different cropping systems at the field scale. The goal is to seek a sustainable cropping system to balance crop production while reducing energy consumption and water depletion. In this case, different systems including monocropped maize (Zea mays) (MM), intercropped maize and soybean (Glycine max) (MS), relay cropped of maize with pea (Pisum sativum) (MP) and potato (Solanum tuberosum) (MO), rotation of maize with spinach (Spinacia oleracea) (MI) and ryegrass (Secale cereale) (MR), and using traditional wheat-maize (Triticum aestivum) (MW) as a control. MM, MS, MP and MO were the best systems within a particular range of food supply reduction. The WEF RI of the MM/MS system was the highest (2.96/2.78). Compared to the MW system, the groundwater consumption of MM/MS was reduced by 73.84%/73.84%, and non-renewable energy inputs were reduced by 48.01%/48.30%; however, the food supply decreased by 48.05%/51.70%. The WEF RI of the MP system was 1.98. In comparison with the MW system, the groundwater consumption of the MP system was reduced by 28.46%, and the non-renewable energy inputs were reduced by 42.68%. However, the food supply decreased by 37.13%. The WEF RI of MO system was 1.92. Compared to the MW system, the groundwater consumption of MO was reduced by 11.47%, non-renewable energy inputs were reduced by 32.14%, and the food supply only decreased by 26.27%. In conclusion, we theoretically proposed the following references for cropping systems in the NCP: MM and MS are implemented when the areas has extreme water shortages, MO is implemented when a less than 30% reduction in the food supply capacity is acceptable, and MP is recommended if a 30%–40% reduction in the food supply is acceptable. [ABSTRACT FROM AUTHOR]

Abstract: A spatially referenced biophysical model, the water and nitrogen management model (WNMM), was developed and shown to simulate dynamic soil water movement and soil–crop carbon (C) and nitrogen (N) cycling under a given agricultural management, for the purpose of identifying optimal strategies for managing water and fertiliser N under intensive cropping systems (mainly wheat–maize) in the North China Plain and other regions in the world. A uniform data structure, ARC GRID ASCII format, was used both in GIS and WNMM for achieving a close Model-GIS coupling. A significant part of WNMM adopts and modifies concepts and components from widely used models, with a focus on soil N transformations. WNMM simulates the key processes of water dynamics in the surface and subsurface of soils: including evapotranspiration, canopy interception, water movement and groundwater fluctuations; heat transfer and solute transport; crop growth; C and N cycling in the soil–crop system; and agricultural management practices (crop rotation, irrigation, fertiliser application, harvest and tillage). The model runs on a daily time step at any desired scale and is driven by lumped variables (meteorological and crop biological data) in text data format, and spatial variables (soil and agricultural management) in ARC GRID ASCII format. In particular, WNMM simulates all key N transformations in agricultural fields, including mineralisation of fresh crop residue N and soil organic N, formation of soil organic N, immobilisation in biomass, nitrification, ammonia (NH3) volatilisation, denitrification and nitrous oxide (N2O) emissions. WNMM has been successfully applied in Fengqiu County, Henan Province and Luancheng County, Hebei Province, China at site and regional scales. The key WNMM components were intensively calibrated and verified against comprehensive field measurements of soil water content, evapotranspiration, crop leaf area index and yield, NH3 volatilisation, denitrification and N2O emissions as well as nitrate (NO3 −)–N concentrations in the soil solution. A sensitivity analysis showed that WNMM was sensitive to changes in meteorological variables, soil hydraulic properties, land use and agricultural management. At the site scale, WNMM simulated well soil water content, crop growth and yield, NH3 volatilisation and soil NO3 −–N concentration. There was uncertainty in simulating soil denitrification and N2O emissions, when the predicted peaks of denitrification and N2O emissions at very wet conditions could not be confirmed because of limitations in the acetylene-inhibition method for measuring denitrification. At county scale, WNMM simulation of crop yield in Fengqiu County explained 22% of the variation in observed crop yields, and 31% of crop yield variation in Luancheng County where soil variation was less. These results are considered acceptable because factors such as soil salinity and other nutrient deficiencies, which have not been considered in this version of WNMM, may play a role. The source code for the WNMM is available on request. [Copyright &y& Elsevier]

Abstract: Wheat (Triticum aestivum L.) and corn (Zea mays L.) rotation system is important for food security in the Loess Plateau of China. Grain yield and water-use efficiency (WUE: grain yield per unit of water consumed) trends, and changes in soil properties during a 24-year fertilization experiment in Pingliang, Gansu, China, were recorded. Mean yields of wheat for the 16 years started in 1981 ranged from 1.29tha-1 for the unfertilized plots (CK) to 4.71tha-1 for the plots that received manure (M) annually with inorganic nitrogen (N) and phosphorus (P) fertilizers (MNP). Corn yields for the 6 years started in 1979 averaged 2.29 and 5.61tha-1 in the same treatments. Yields and WUEs declined significantly with lapse of time except CK and MNP for wheat. Wheat yields with the N and M declined at rate of 77 and 81kgha-1year-1, but the decline of 57kgha-1year-1 for NP was similar to that of 61ha-1year-1 for straw with N annually and P every second year (SNP). Likewise, the corn yields and WUEs declined from 160 to 250kgha-1year-1 and from 0.01 to 0.03kgm-3year-1 among treatments, respectively. These declines were likely to loss of soil fertility and gradual dry weather. Yields were significantly correlated with seasonal evapotranspiration with slopes ranging from 0.5 to 1.27kgm-3 for wheat and from 1.15 to 2.03kgm-3 for corn. Soil organic carbon (SOC), total N (TN), and total P (TP) gradually built up with time except the CK, in which TN and TP remained unchanged but SOC and available P (AP) decreased. Soil AP decreased in the N. Soil available K declined rapidly without straw or manure. Balanced fertilization should be encouraged to ensure sustainable productivity in this intensive cropping system. The greatest SOC increases of about 160mgha-1year-1 occurred in the SNP and MNP, suggesting that long-term additions of organic materials to soil could increase soil water-holding capacity which, in return, improves water availability to plants and arrests yield declines, and decrease CO2 emission from agricultural soils and sustain land productivity. [Copyright &y& Elsevier]

• Modeling yield, evapotranspiration and economic profit in different cropping systems using APSIM under projected climate scenarios. • Maize and wheat yield underwent significant reduction in projected scenarios compared with the baseline data. • Plant transpiration have not changed significantly between scenarios, but evaporation decreased in some conditions markedly. • Lucerne-winter wheat rotation presented the greatest potential of the sustainability under projected scenarios. Agriculture in the semiarid region is undergoing radical changes driven by global warming and increasing incidences of extreme weather events. Predicting and evaluating the responses of crop yield and water use patterns of rainfed cropping systems according to future temperature and precipitation changes could provide important information regarding adoption of climate-smart farming systems that could offer great resilience and sustainability. The objective of this study was to evaluate the potential changes in agronomic productivity, hydrological balance and economic profitability of cropping systems with perennial legumes and rotation on the Loess Plateau of China affected by different future temperature and precipitation scenarios using APSIM-based modeling. Five different cropping systems were investigated: (i) continuous maize (Zea mays) (M), (ii) continuous winter wheat (Triticum aestivum) (W), (iii) continuous lucerne (Medicago sativa) (L), (iv) maize-wheat-soybean (Gyleine max) rotation (MWS) and (v) lucerne (4-yr)-winter wheat (2-yr) rotation (LW) in Xifeng, Gansu, China. Five series of temperature and precipitation changes scenarios (no changes in atmospheric CO 2 concentrations were considered) based on RCPs (representative concentration pathways) were integrated into scenario simulations, including the baseline scenario (1980–2010), mid-century scenarios of RCP4.5 (M45) and RCP8.5 (M85), and end-century scenarios of RCP4.5 (E45) and RCP8.5 (E85). The results showed that, compared with baseline simulations, mean maize yield under RCPs decreased by 6.7 %–37.7 %, and the mean wheat yield decreased by 1.7 %–23.6 %. Lucerne yield consistently increased by 7.2 %–12.3 % under M45 and E45. Although different cropping systems affected the yield to a certain extent, only the difference between the wheat yields of W and MWS was significant (P < 0.05). On a cropping system level of every 6-yr (totally five phases for a scenario of 30-yr), the temperature and precipitation changes did not significantly affect plant transpiration (T c) per phase. For all systems except L [which received its highest soil evaporation (E s) per phase in baseline], the greatest E s per phase was found in the E85. L tended to provide greater T c per phase and evapotranspiration (ET) per phase (ranging from 1219 to 1332 mm and 2910–3034 mm, respectively), followed by LW. L and MWS presented the highest and lowest E s per phase (1636–1724 and 1592–1677 mm), respectively. The gross profit (GP per 6-yr phase) and water productivity (WP per 6-yr phase) of L were the greatest among all cropping systems (11.5–13.7 thousand US$ ha−1 per phase and 3.72–4.41 US$ ha-1 mm-1 per phase, respectively), followed by LW and MWS. For M, W and MWS, the GP per phase and the WP per phase were predicted to be greater under the baseline than under any of the RCPs, whereas M45 and E45 scenarios improved the GP per phase and WP per phase of L and LW compared with those of the baseline. In general, we advocate that LW-based systems have the greatest potential for producing acceptable yield and economic profit under future temperature and precipitation scenarios for this local environment. [ABSTRACT FROM AUTHOR]