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Continuous monitoring of soil quality is vital to understand the effects and to identify best management practices for sustainable agroecosystems. This study focuses on evaluating the soil quality and crop yield sustainability in a long-term maize-wheat cropping system experiment spanning 47 years. Physical, chemical, and biological soil quality indicators were assessed at two soil depths (0–0.15 m and 0.15–0.30 m) under eleven fertilizer and amendment regimes i.e., 50 % NPK, 100 % NPK, 150 % NPK, 100 % NPK + Zn, 100 % NPK+ hand weeding, 100 % NP, 100 % N, 100 % NPK + farmyard manure (FYM), 100 % NPK(S), 100 % NPK + lime and control, laid out in a completely randomized block design. Principal component analysis (PCA) was employed to select a minimum data set (MDS) of indicators for soil quality assessment, followed by weighted additive approach to calculate the soil quality index (SQI). Results showed that balanced dose of NPK fertilizers, in combination with FYM or lime, enhanced average wheat grain yield by 39.9 and 29.4 % over sole 100 % NPK fertilizers, respectively. Treatment 100 % NPK + FYM recorded a significant improvement in aggregate stability, available nutrients, microbial biomass over control and 100 % NPK. The highest value of SQI (0–0.15 m) was recorded in 100 % NPK + FYM (0.99), followed by 100 % NPK + lime (0.86) and lowest in 100 % N (0.41). Omission of NPK, PK, K and S from fertilizer regime caused a decline of respective 33, 39, 22 and 6 % in the SQI, whereas, all the treatments recorded a decline in SQI in sub-surface layer. The average contribution of MDS towards the SQI of 0–0.15 and 0.15–0.30 m depth was labile carbon (LC) (30 %) > microbial biomass N (MBN) (28 %) > mean weight diameter (MWD) (17 %) > pH (16 %) > available K (6 %) and LC (33 %) > N mineralization (24 %) > MWD (22 %) > pH (21 %), respectively. The SQI positively correlated with average grain yield and SYI, highlighting the importance of soil quality for sustainable crop production. This research underscores the significance of continuous soil quality monitoring and use of balanced fertilization, organic manure and lime in maintaining soil health and crop productivity in agroecosystems. • Balanced NPK fertilizers with FYM or lime increased the wheat yield by 39.9 and 29.4 %, respectively. • Continuous urea application rendered the soil unproductive. • Labile carbon was the major contributor towards the soil quality index. • Soil quality index correlated positively with grain yield and sustainable yield index. [ABSTRACT FROM AUTHOR]

• Sobol' method is used to evaluate the sensitivity of APSIM-Wheat yield predictions. • Yield is most sensitive to initial nitrogen amount, soil parameters, precipitation. • Estimated yield is influenced most by the limiting resource under given conditions. • Scenarios for high fertilization level or dry seasons have lower yield variability. The performance of cropping system models is often limited by uncertainties in model parameters and inputs. This study aims to explore how model yield prediction responds to these uncertainties under various environmental and management conditions. The Sobol' method was used to investigate the sensitivity of the Agricultural Production Systems SIMulator (APSIM)-Wheat yield prediction to the following factors: air temperature (maximum and minimum), precipitation, initial soil nitrogen content, nitrogen fertilization amount, and soil hydraulic parameters. Eighteen scenarios were defined to consider a combination of three weather conditions (wet, normal, and dry growing season, based on the historical climatology of the Wimmera district of Victoria, Australia), three soil types (sandy, loamy, and clayey soils), and two nitrogen fertilization applications (50 and 100 kg N/ha). Eight thousand APSIM simulations were used to calculate the first order and total sensitivity indices for each scenario. The effects of weather, soil water characteristics and nitrogen availability were estimated by measuring their impacts on sensitivity indices. Our results show that yield was more sensitive either to variables that control water availability (precipitation and soil type) or variables that control nitrogen availability, depending on which was more limiting to wheat growth under the scenario. For example, in case of low nitrogen fertilization scenario, the initial nitrogen content sensitivity ranked first. Variation of this factor contributed 64% to 79% to the variance in simulated yield for clayey soils, nearly four times higher than the second-ranked factor (nitrogen fertilization amount). Soil hydraulic parameters and precipitation were most important when the crop growth was more constrained by water availability than by nitrogen availability. In the case of sandy soils in dry years with high nitrogen fertilization level, soil parameters and precipitation accounted for 83% of the yield variability. Minimum temperature consistently ranked as the least important factor under all scenarios. This work will help researchers better understand the model inputs' impacts on the simulated yield variability under various soil, management, and weather conditions. The results also support agronomists and practitioners in the optimal use of the APSIM-Wheat model as a management tool. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract The effects of diversifying wheat-based cropping systems in the Northern Great Plains (NGP) on soil chemical and physical properties is well documented: better soil tilth, improved water infiltration, and higher soil organic matter with crop rotations. However, the impact of crop rotations on soil biology is not as well understood. Nematode communities reflect soil quality and are directly observable, readily quantifiable, and occupy most of the consumer trophic levels in the soil food web. Within more humid climates, the community structure is better characterized to make associations with soil health and crop management strategies, but little is known about their community structure in semiarid regions such as the NGP. For this study, soils under contrasting cropping systems were sampled in the 15th year of a long-term study to quantify and assess the nematode community. Prior to planting, wheat-chemical fallow had a higher total nematode population than that of wheat-tilled fallow (P < 0.05). A wheat-pulse system with a history of crop perennation had a greater abundance of uncommon, omnivorous nematodes than a wheat-pulse system without a prior history of crop perennation. However, plant parasitic nematodes also were higher in abundance under the converted perennial system. Our results suggest that reducing soil disturbance and including a perennial component to cropping systems will foster a more diverse and balanced nematode community under semiarid dryland conditions, but potentially at the expense of increased plant parasitic nematode pressure. [ABSTRACT FROM AUTHOR]

Global climate change associated with increasing temperature and unreliable rainfall events will have consequences for crop production. Therefore, strategizing crop management gained the attention of crop scientists to curtail the adverse impacts of climate change on crop production. However, the projected effects of climate change on wheat may vary in different cropping systems as wheat production is reported to be significantly impacted by future climate change in major cropping systems worldwide. In the present study, ten experiments were conducted under irrigated (2007–2013) and rainfed (2010–2014) cropping systems of Pakistan to quantify the interactive impacts of future climate change (CO 2 , temperature, and rainfall) on wheat phenology, grain yield, crop evapotranspiration (ET c), and water use efficiency (WUE) using the DSSAT-CERES-Wheat. The DSSAT-CERES-Wheat was executed using 17 Global Climate Models (GCMs) and four Representative Concentration Pathways (RCPs; 2.6, 4.5, 6.0, and 8.5) to forecast the climate projections for 2030, 2050, and 2090. The average temperature at both sites will increase by 1.3, 1.9, 1.9, and 2.9 ℃ under RCP 2.6, 4.5, 6.0, and 8.5. The simulated output varies among GCMs, RCPs, CO 2 concentration, and future periods. A general reduction in wheat phenology, grain yield, ET c , and WUE was anticipated. However, higher CO 2 concentration and early maturity improved the WUE of wheat under irrigated and rainfed conditions. Nevertheless, this gain in WUE was at the cost of a relatively higher yield loss. Wheat yield is expected to decline by 2–19% and 9–30% under irrigated and rainfed conditions, respectively by aggregating the simulated future climate change impacts across GCMs and RCPs. Adaptation strategies to mitigate the climate change impacts on wheat production in irrigated and rainfed areas will be required. Our findings will serve as a foundation for designing future climate change adaptation strategies to sustain wheat production in Pakistan's irrigated and rainfed cropping systems. • Climate change jeopardize wheat productivity of irrigated and rainfed wheat world wide. • CERES-Wheat was executed using 17 GCMs and 4 RCPs for 2030, 2050, and 2090. • Increasing temperature and declining rainfall trend was observed for both locations. • Wheat phenology, grain yield, ET c , and WUE declined under future climate change. • Adaptation strategies are required to reduce adverse effects of climate change. [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]

Arbuscular mycorrhizal (AM) fungi form potentially symbiotic associations with most crop species and potentially increase crop phosphorus (P) uptake in intensive cropping systems. Their widespread use, however, remains restrained by our limited understanding of the processes that determine the outcome of the associations. Here, we have used 32P to quantify the delivery of P to maize (Zea mays L.) and wheat (Triticum aestivum L.) via indigenous AM fungi in compartmented pots under high- and low-P conditions. Soil P level was important in driving shoot P uptake via the direct root pathway (DP) or the mycorrhizal pathway (MP). The MP contribution reached 81.8 and 75.8%, respectively, in maize and wheat at low P status but declined to 40.6 and 9.1% at high P. The abundance of intraradical and extraradical colonization and the relative abundance of Rhizophagus and shoot P utilization efficiency (PUE) significantly impacted the MP contribution. Larger mycorrhizal P and growth responses were closely related to a higher MP contribution and shoot PUE in maize but only P response was significantly related to the latter in wheat. These results suggest that crops can acquire considerable amounts of P via the MP with indigenous AM fungi, especially at low P levels, and highlight the importance of plant and AM fungal identity in regulating the relationship between hidden P uptake and symbiotic outcomes. Therefore, manipulation of fertilizer P application rates to optimize the abundance and assemblage of the indigenous AM fungi and crop PUE to increase MP activity and symbiotic outcomes may contribute to the efficient utilization of AM fungi in intensive cropping systems. • Crops took up considerable amounts of P via AM fungi but were regulated by P level. • AMF colonization, Rhizophagus abundance and shoot PUE affected the MP contribution. • The relationship between MP contribution and MGR differed between maize and wheat. [ABSTRACT FROM AUTHOR]

The remarkable expansion of fertilization and irrigation may stimulate nitrous oxide (N 2 O) emissions from cropping systems in northern China. High-resolution measurements were conducted in irrigated cotton and wheat–maize rotational systems in Shanxi Province, P.R. China, between 2007 and 2010 (three year-round crop cycles, hereinafter referred to as Y1, Y2 and Y3) to investigate the impacts of natural inter-annual variations and agricultural management on annual N 2 O emissions and direct emission factors (EFs). Overall, N 2 O emissions fluctuated diurnally, seasonally and inter-annually in the fertilized treatments. The hourly N 2 O fluxes closely followed the daily air temperature patterns. The daily mean fluxes corresponded to these hourly fluxes, which were observed between 09:00–10:00 and 19:00–20:00. An optimized sampling protocol could improve the reliability of discrete measurements when estimating cumulative emissions. The N 2 O emissions for the fertilized treatments were 2.7 ± 0.2 (Y1) and 1.6 ± 0.1 kg N ha −1 yr −1 (Y2) from the cotton field and 6.2 ± 0.4 (Y1), 4.5 ± 0.3 (Y2) and 4.5 ± 0.2 kg N ha −1 yr −1 (Y3) from the wheat–maize field. Peak N 2 O emissions after fertilization and irrigation/rainfall lasted one to three weeks and accounted for 16–55% of the annual emissions. Leaching losses were estimated at 10.4 ± 3.0 (Y1) and 12.5 ± 3.4 kg N ha −1 yr −1 (Y2), which accounted for 16–17% of the fertilizer-N applied to the cotton field. Annual N 2 O emissions did not increase with increasing fertilization rates or water inputs because significant amounts of fertilizer-N were lost through leaching. Background emissions amounted to one-third to one-half of the total N 2 O emissions from the fertilized treatments. The direct EFs were 2.2 ± 0.3% (Y1) and 0.9 ± 0.2% (Y2) in the cotton field and 1.3 ± 0.2% (Y1), 0.8 ± 0.1% (Y2) and 0.7 ± 0.1% (Y3) in the wheat–maize field. The large inter-annual variations in N 2 O emissions and direct EFs emphasize the importance of multiple-year continuous observations. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conventional tillage left negative carbon footprint. [•] CH4 was largest contribution to carbon footprint. [•] Continuous no tillage was highest yielding practice. [•] Discontinuous tillage practice was worst environmental performer. [ABSTRACT FROM AUTHOR]

Abstract: Understanding water and nutrient utilization in agricultural layered soil is very important for the improvement of agricultural management and protection of the environment. The objective of this paper is to determine the effect of layered soil profiles on crop yield and water and fertilizer nitrogen (N) utilization. Firstly a water and nitrogen management model (WNMM) was calibrated and validated under a wheat–maize cropping system in an alluvial plain using published data of two soil profiles (named A and B). The results showed that the model can be used to simulate the water movement and N transport, as well as crop growth in the study area. Then, another three very different soil profiles (named C, D and E) near to profiles A and B were studied. The profile C had a silt loam–clay profile; the profile D had a silty loam–clay–silt profile and the profile E had a clay–silty loam–silt profile. The soil hydraulic parameters of these profiles were obtained by pedo-transfer functions using measured soil properties. Given the same initial conditions and field management practices, the WNMM was then used to simulate water and Nitrogen balance and crop yield for the three profiles. Simulated results showed that the profiles (C, D and E) have similar water and fertilizer N use efficiencies (WUE, FNUE), while the crop yields of profiles C and D were higher than that of the profile E. Compared with profiles D and E, the profile C has least water drainage (127 mm) and total N loss (117 kg N ha−1). We concluded that layering of soil profiles has a strong effect on water and fertilizer N utilization and crop yield. Such an effect of layered property of soil profiles, therefore, needs to be taken into account in precision agriculture related research. [Copyright &y& Elsevier]

Abstract: Biofuels could become increasingly important for agriculture; however there is growing concern regarding the possible environmental drawbacks due to the risks of increased inputs during crop cultivation. These risks need to be evaluated in order to assess the best management practices. In this study, a life cycle assessment (LCA) was carried out: (i) to evaluate the environmental impacts of three cropping systems characterized by different external input levels (low S1, medium S2 and high S3) applied to sunflower and maize, both in rotation with wheat, in a Mediterranean region; (ii) to estimate the environmental benefits of the optimization of cropping systems for energy management. Output–input ratio, net energy balance, global warming potential (GWP), eutrophication potential (EP) and acidification potential (AP) were used as LCA impact categories. Data from cropping systems (external input and crop yields) were collected from a long-term experiment carried out in the coastal plain of Tuscany; data regarding fertilizers, machinery and pesticide production were taken from literature. The results obtained showed S1 with the highest output–input ratios and the lowest impact for the selected impact categories. The other cropping systems S2 and S3 showed limited differences between them for all the impact categories evaluated. Fertilizer use and application, irrigation and machinery use caused most of the environmental impacts and energy consumption. The allocation procedure, showing residues as co-products, had a strong influence on the overall efficiency of agricultural 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]

The North China Plain (NCP) is an important production base for wheat (Triticum aestivum L.) and maize (Zea mays L.) in China, but intensive continuous winter wheat and summer maize (WM) double-cropping system (control) has also created the high carbon footprint (CF) ecological problems. It is imperative to build a new rotation pattern that not only achieves direct and indirect low greenhouse gases (GHG) emissions, but also takes into account the grain security. CF metrics (per unit area (CF a), per unit economic output (CF e) and per unit kg grain yield (CF y)) were calculated for a two-year crop rotation experiment established at the Wuqiao Experimental Station, from October 2016 to September 2018. The treatments were eight alternative crop sequences grown in the first year, followed by WM in the second year. Alternative crop sequences included (1) WM, (2) fallow, (3) spring maize, (4) winter wheat, (5) spring sweet potato (Dioscorea esculenta (Lour.) Burkill), (6) spring peanut (Arachis hypogaea Linn.), (7) winter wheat-summer peanut, and (8) potato (Solanum tuberosum L.) - silage maize. The results showed that fallow → WM and winter wheat → WM were weak absorption sinks of net GHG, and other rotation patterns were all net sources during the experimental period, while the seven rotation patterns could attain 48%–94% of grain crops yield in control. Spring sweet potato → WM and winter wheat - summer peanut → WM, had no significant differences with control from three different CF perspectives. Spring maize → WM, spring peanut → WM, and potato - silage maize → WM produced more CF than control. Therefore, fallow and planting winter wheat alone in the first year of novel two-year rotation patterns reduced CF in the NCP, planting spring sweet potato and winter wheat-summer peanut increased net income without increasing CF and without compromising grain security, which could attain 1.53 and 1.12 times of the control. The research preliminary showed that winter wheat → WM, spring sweet potato → WM and winter wheat - summer peanut → WM were feasible to trade off of grain production and reducing CF. • Exploring the novel rotation patterns and trying to ensure grain security while reducing carbon emissions. • Compared with winter wheat and summer maize (WM), fallow→WM and W→WM were weak absorption sinks and required fewer resources. • Spring sweet potato→WM and W-summer peanut→WM increased net income, without increasing CF and compromising grain security. [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]

• 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]

The assessment of GHG emissions from spring wheat cropping system in Saskatchewan was conducted in this study. A general emission assessment model was developed. The main sources of GHG included emissions from farming operations, emissions from the manufacturing and transportation of N/P fertilizer, emissions from herbicides usage, and direct and indirect land emissions. The total GHG emission was around 3.36 × 106 Mg CO 2 -eq in 2012. The total GHG emissions mainly came from the manufacturing, storage, delivery, and application of nitrogen fertilizer and environmental conditions had a significant effect on GHG emissions. From north to south Saskatchewan, the total GHG emission was decreasing as Pr/PE decreased. In high Pr/PE area, there was a GHG emission of 474 kg CO 2 -eq t−1 of grain, which was 41% greater than that in low Pr/PE. Through applying multivariate factorial analysis, it was found that the emission factor from direct emission had the most significant impact on the total GHG emission. The total GHG emission in higher Pr/PE area was more sensitive to the N fertilizer application. The understanding of detailed effects of these parameters and interactions can help determine what would have significant effects on total GHG emission and develop the appropriate strategy for sustainable management of agriculture. [Display omitted] • A framework for assessing regional GHG emission from cropping was established. • The GHG emission from spring wheat cropping system in Saskatchewan were assessed. • The total GHG emission from was around 3.36 × 106 Mg CO 2 -eq in 2012. • There were geographic variability and spatial heterogeneity of GHG emissions. • The direct emission factor had the most significant impact on total GHG emission. [ABSTRACT FROM AUTHOR]