Rainfed Cropping Systems Research Articles

Impact of biochar application on nitrous oxide and methane emissions in rainfed cropping systems within a semiarid region

AbstractThis study investigated the impact of biochar on Zea mays L. yield and greenhouse gas (GHG) emissions in rainfed maize fields in Northwest China. Four treatments were compared: unmodified control (CK), conventional nitrogen (BC0), nitrogen + 20 t ha−1 biochar (BC20), and nitrogen + 50 t ha−1 biochar (BC50). Results showed significant increases in grain yields with BC20 (11.1%) and BC50 (8.6%) compared to BC0. Emissions of nitrous oxide (N2O) were reduced by 14.0%–19.5% in biochar treatments compared to CK. Methane (CH4) uptake by the fields, acting as CH4 sinks, was not significantly impacted by biochar treatments, clarifying that the biochar did not alter the farmland's inherent ability to uptake CH4. Over 2 years, the addition of nitrogen fertilizer and biochar did not markedly alter cumulative CH4 uptake. Both net greenhouse gas (NGHG) emissions and yield‐scaled GHG intensity (NGHGI) were lowered by 16.7%–23.5% and 24.2%–30.3%, respectively, with biochar application. The integration of biochar effectively mitigated the GHG emission enhancement due to nitrogen fertilizer, mainly by decreasing nitrogen oxide emissions and boosting maize yields. Thus, proper biochar application would be an economical and effective strategy for mitigating gas emissions from rainfed maize cropping system in semiarid regions.

Rethinking environmental sustainability in rainfed cropping systems

Activity data from a 30-year on-farm experiment with six soil-management treatments were used to develop inventory data for environmental partial life-cycle assessment (LCA). The purpose was to compare the treatments based on environmental outcomes and evaluate conservation agriculture (CA) in Australia's dryland cropping zone. Multiple trade-offs were revealed that highlight the need for a nuanced approach to sustainable intensification and show that rules-based CA is not sufficient to guarantee low greenhouse gas (GHG) emissions, nor low overall environmental impact. Nutrient mining in dryland cropping even under CA can lead to losses in soil carbon that can double GHG intensity. In these systems, additional nutrient inputs can reduce the loss of soil carbon as well as net GHG emissions, demonstrating the critical need to include the effects of soil carbon change in LCA to prevent perverse outcomes.The treatment involving strategic tillage and nutrient balancing, along with stubble retention, had the lowest GHG intensity, but there was a trade-off with the higher embedded impacts across several other environmental categories. Higher fertiliser input could lead to toxicity impacts, due to heavy-metal content, that contribute significantly to the Human health endpoint. However, limitations in modelling such local, site-specific impacts were considerable and more research is needed to address this.In general, trade-offs were found to exist between impacts from on-farm activities versus upstream manufacture of inputs; between GHG emissions and land use (yield) versus other environmental categories; and between different on-farm GHG emission sources. Despite these trade-offs, the treatments all had similar overall scores in the Human health and Ecosystems damage categories. There was no single treatment with low, or high, impact scores across all environmental indicators, indicating that trade-offs need to be carefully considered when making farm-management decisions in the context of net-zero or carbon-neutral farming.

Reducing energy and carbon footprint through diversified rainfed cropping systems

Agriculture is the second largest contributor (20 %) to total anthropogenic greenhouse gas (GHG) emissions in the world. There is a need to identify energy and carbon efficient cropping systems that reduce GHG emission and improve environmental quality. Using life cycle assessment (LCA), we evaluated the four cropping systems namely fallow – chickpea (F–C); Sesbania – mustard (Ses–M); blackgram – chickpea (B–C); sorghum + cowpea – mustard (S + C–M) cultivated during the 2018–2022 period. The energy use pattern and the input-output relationship were analysed. Three measures were utilized to quantify carbon footprints: CFa, which denotes emissions per unit area; CFb, indicating emissions per kilogram of yield; and CFe, representing emissions per unit of economic output. The result indicates that non-renewable sources of energy (diesel and fertilizer) contributed more than ∼80 % of the total energy consumed in the different cropping systems. The total energy requirement was the highest for S + C–M (16,972 MJ ha–1), followed by Ses–M (14,365 MJ ha–1), B–C (11,132 MJ ha–1) and F–C (8679 MJ ha–1) cropping systems. The S + C–M cropping system also had the highest energy use efficiency (9.13) followed by F–C (6.03), B–C (5.41) and Ses–M (5.41). The fallow–chickpea cropping system had the lowest values of CFa, CFb, and CFe however, the highest carbon efficiency (10.7) and the carbon sustainability index (9.7) were computed in S + C–M cropping system. Our findings indicate that thoughtfully structured, varied crop systems that integrate legumes and forage crops have the potential to significantly reduce energy consumption and carbon emissions, while sustaining or potentially improving overall productivity within these systems.

Enhanced efficiency nitrogen fertilizers (EENFs) can reduce nitrous oxide emissions and maintain high grain yields in a rain-fed spring maize cropping system

ContextEnhanced efficiency nitrogen fertilizers (EENFs) have provided opportunities for the simultaneous mitigation of nitrous oxide (N2O) emissions and increases in crop productions. However, the practice of combining EENFs with optimal fertilization under conditions of misaligned water and fertilizer inputs in rain-fed spring maize systems remains inadequately understood. ObjectiveThis study aims to determine the factors controlling N2O emissions under the soil climatic conditions in rain-fed plastic mulching cropping systems treated with different nitrogen (N) fertilization rates and EENFs, and to determine the most effective N fertilization measure to reduce N2O emissions while maintaining crop yields. MethodsA 3-year field experiment was conducted in a spring maize system located in the semiarid rain-fed region of the Loess Plateau, applying two types of EENFs: a nitrification inhibitor dicyandiamide (DCD) and a slow-release fertilizer (SRF). It comprised five fertilization treatments: unfertilized (CK), conventional N rate (CON, 200 kg N ha−1), optimal N rate (OPT, 160 kg N ha−1), OPT with the addition of DCD (OPT+DCD), and OPT using SRF (OPT-SRF). ResultsThe average annual cumulative N2O emissions over the 3-year experimental period ranged from 0.74 to 1.87 kg N2O-N ha–1. Fertilizer N contributed 26−60% to annual N2O emissions. The highest N2O fluxes (50–161 μg N2O-N m–2 h–1) typically occurred within the initial 10 days following fertilization, likely induced by strong nitrification processes, constituting 12–19% of the annual N2O emissions during this brief period. In comparison to the CON treatment, the OPT, OPT+DCD, and OPT-SRF treatments resulted in significant reductions in annual N2O emissions of 24%, 46%, and 34%, respectively, without causing any significant decrease in maize grain yields. The application of DCD led to increased ammonium (NH4+-N) concentrations while reducing nitrate (NO3–-N). Conversely, using SRF resulted in a decrease in both NH4+-N and NO3–-N concentrations. ConclusionsUsing EENFs at the ideal fertilization rate significantly curtailed yearly N2O emissions without adversely affecting maize yields in a rain-fed plastic mulching spring maize system prevalent in the Loess Plateau. Most N2O emissions occurred post-fertilization, with rainfall events further influencing these emissions. ImplicationsOur findings recommend the incorporation of nitrification inhibitors, such as DCD, as the most effective fertilizer measure for reducing N2O emissions in the rain-fed region of the Loess Plateau.

Utilization of cotton gin waste biochars for agronomic benefits in soils

AbstractCotton gin waste (CGW) is produced in large quantities (1–1.5 × 106 metric ton/year) in the Texas High Plains (THP), one of the largest cotton-producing regions in the USA. We examined locally supplied CGW for soil amendment as biochar (CGW-BC) with a view toward rainfed cropping systems, which will likely become increasingly necessary due to declines in groundwater availability for irrigation. Sixteen unique biochar samples were produced under varying conditions of time, temperature, and post-processing wash in a muffle furnace. We performed material characterization on the biochar. We then incubated CGW-BC samples that seemed favorable for increasing the water holding capacity increase for 10 days with local, rainfed, clay loam soil. We found that increasing the pyrolysis time and temperature decreased the biochar yield but only up to 40 min. Beyond 40 min, the yield did not decrease further. Additionally, the majority of mass loss occurred during pyrolysis and not during crush-sieving or postproduction washes. CGW-BC produced at higher temperatures and for longer times had greater thermal stability. This interesting aspect of thermal stability, which did not always follow strict time‒temperature trends, may be because cotton gin waste is a heterogeneous material. We found that the addition of acid decreases the mineral content while lowering the thermal stability of lower temperature (450 °C) biochars. Regarding the CGW-BC surface area, we found that higher temperatures generally increase the micropore surface area. Using a GAB isotherm, water vapor surface area did not correlate with the highest WHC when water was added to the soil. In fact, biochar, which was pyrolyzed in less time at a lower temperature and with the use of acid washing, better held the water in soil-biochar mixtures. The measurements suggested that CGW-BC could be a valuable soil amendment that could increase the WHC without adversely increasing the pH. Our initial investigation revealed how scaled-up production of CGW-BC for soils might be economically and sustainably pursued for use in rainfed cropping, deficit irrigation, or ranchlands.

Measurement and estimation of evapotranspiration in a maize field: A new method based on an analytical water flux model

Quantifying evapotranspiration (ET) in rainfed cropping systems can be challenging due to complicated interactions among site-specific soil, plant, and management factors. In Northeast China, ET and soil water status in maize fields often display strong spatial and temporal variations due to the changes in tillage practice, planting pattern, and maize plant density. Previous studies have shown that near-surface soil water content (θ) observations at multiple scales provide the potential to estimate surface soil water fluxes. In this study, we introduced a new method to estimate daily field ET by using a soil water flux model mainly based on the time-series of θ at a depth of 2.5 cm. The new method required a calibration of soil water diffusivity with maximum net water flux in the near-surface soil layer, which was related to precipitation redistribution below the canopy. Finally, the new method was evaluated using observed ET values over a 2-year period in a maize field, where independent measurements of soil water evaporation (E) and transpiration (T) were made with heat-pulse sensors and sap-flow gauges, respectively. Field observations showed that E dominated water loss during the seedling stage (16% of total ET). As the canopy was fully developed, E sharply decreased to a value of 0.4 mm d−1, and T accounted for about 89% of ET since the silking stage. The new method to estimate ET performed well in drying periods, while it tended to underestimate ET in wet periods with substantial infiltration into the surface layer. On rain-free days, the ET values estimated with the new method matched well with the measured E+T values, with R2 and RMSE values of 0.85 and 1.93 mm d−1. Therefore, the new approach provides an effective way to quantify maize ET.

Soil responses to inclusion of corn, soybean, and cover crops under rainfed conditions in the northern Great Plains

Crop rotations in the northern Great Plains of North America increasingly include corn ( Zea mays L.) and soybean ( Glycine max (L.) Merr.). Use of cover crops, while less extensive, is also increasing given their purported agronomic and environmental benefits. To date, soil responses to the inclusion of corn, soybean, and cover crops in rainfed cropping systems have not been well documented in the region. Therefore, soil properties were evaluated 6 years after establishment of three crop rotations (spring wheat ( Triticum aestivum L.)–soybean (SW–S), spring wheat–corn–soybean (SW–C–S), and spring wheat–corn–cover crop (SW–C–cc)) each split by no and minimum tillage on a Dark Brown Chernozem near Mandan, ND, USA. Soil responses to treatments were subtle and exclusive to the 0–7.6 cm depth. Soil pH was lower in SW–S than SW–C–cc (5.28 vs. 5.48; P = 0.05), SO4-S was greater under SW–C–cc than SW–C–S (13.4 vs. 11.6 g S kg−1; P = 0.03), exchangeable K was greater under SW–C–S and SW–C–cc than SW–S (0.83 cmol kg−1 vs. 0.52 cmol kg−1; P = 0.05), and water-stable aggregates were greater in SW–S than SW–C–S (26% vs. 19%; P = 0.08). Soil organic carbon (SOC) and total N did not differ among crop rotations or between tillage treatments, while particulate organic matter N was greater under no tillage compared to minimum tillage ( P = 0.08). Between 2012 and 2018, soil pH decreased and SOC increased under SW–C–S. Frequent monitoring of near-surface soil conditions in rotations with soybean every other year is recommended. Furthermore, innovative management practices are needed to enhance soil C and N fractions in rotations with full-season cover crops.

Economic Performance of Rainfed Wheat-Double Crop Systems under Weed Competition

AbstractThis study examines the economic performance of rainfed cropping systems endemic to the Southern Great Plains under weed competition. Cropping systems include tilled and no-till wheat-fallow, wheat-soybean, and wheat-sorghum rotations. Net returns from systems are compared under different levels of weed pressure. Producers operating over longer planning horizons would choose to double-crop regardless of the tillage method used and weed pressure level. Producers operating under shorter planning horizons would implement wheat-fallow systems when weed pressure is high and double crop when weed pressure is low.

Elucidating the interactive impact of tillage, residue retention and system intensification on pearl millet yield stability and biofortification under rainfed agro-ecosystems.

Micronutrient malnutrition and suboptimal yields pose significant challenges in rainfed cropping systems worldwide. To address these issues, the implementation of climate-smart management strategies such as conservation agriculture (CA) and system intensification of millet cropping systems is crucial. In this study, we investigated the effects of different system intensification options, residue management, and contrasting tillage practices on pearl millet yield stability, biofortification, and the fatty acid profile of the pearl millet. ZT systems with intercropping of legumes (cluster bean, cowpea, and chickpea) significantly increased productivity (7-12.5%), micronutrient biofortification [Fe (12.5%), Zn (4.9-12.2%), Mn (3.1-6.7%), and Cu (8.3-16.7%)], protein content (2.2-9.9%), oil content (1.3%), and fatty acid profile of pearl millet grains compared to conventional tillage (CT)-based systems with sole cropping. The interactive effect of tillage, residue retention, and system intensification analyzed using GGE statistical analysis revealed that the best combination for achieving stable yields and micronutrient fortification was residue retention in both (wet and dry) seasons coupled with a ZT pearl millet + cowpea-mustard (both with and without barley intercropping) system. In conclusion, ZT combined with residue recycling and legume intercropping can be recommended as an effective approach to achieve stable yield levels and enhance the biofortification of pearl millet in rainfed agroecosystems of South Asia.

Spatio-Temporal Drought Assessment Using Standardized Precipitation Evapotranspiration Index (SPEI) over Mantaro Valley, Peru

Peru has several studies based on the Peruvian Tropical Andes (PTA) and its effects due to climate change. It has been shown that due to orography characteristics, different kinds of climate conditions are seen. In that sense, the PTA has a very complex climate system, which causes significant variability mostly related to an increase in temperature and a decrease in precipitation patterns. The Mantaro Valley is located in the PTA, Junin region. Where vulnerable farmers are already affected by poverty, practice agriculture based on rain-fed cropping systems. Hence, climate variability causes agricultural vulnerability and water resource scarcity. This study aims to elaborate the Spatio-temporal drought assessment over Mantaro Valley to provide information on local climate change events. In order to do so, the Standardized Precipitation Evapotranspiration Index (SPEI), recognized by the World Meteorological Organization (WMO), was used. The results have shown that almost every station has clear evidence of warming over the years and only a precipitation decrease in two out of six stations. Furthermore, the Spatio-temporal analysis shows around 30% of drought events from the total data, considering the frequency, severity, and duration. In conclusion, it has been demonstrated that all analyzed stations within Mantaro Valley have the same deportment regarding drought characteristics with different highest frequency per time scale. Finally, it is recommended to keep tracking stations with the lowest available data, realize comparison analysis with different drought assessment methods, and study the correlation between drought and ENSO events and other climate events such as floods.

Determination in Forage Yield and Quality of Chicory and Different Plants Mixtures in Grazing Maturity Period

This study was conducted to determine forage yield and quality of chicory (Cichorium inthybus L.) in a pure stand and a simple pasture (two-species) in the grazing maturity period. The experiment design was a Randomized Block Design with 3 replications. The experimental site was located on the grounds of the Ondokuz Mayıs University Agricultural Faculty during the 2017 and 2018 growing periods. In this study, chicory (C), orchardgrass (OG), and red clover (RC) were grown as forage plant materials in a rainfed cropping system in North Türkiye. Simple pastures comprised of 80%C + 20%OG, 60%C +40%OG, 40%C + 60%OG, 20%C + 80%OG, 80%C + 20%RC, 60%C + 40%RC, 40%C + 60%RC, 20%C + 80%RC. Five sequential harvests were made when chicory plants reached 25 cm of plant height in both years. The average plant height ranged from 17.3 to 35.6 cm, and 29.1 to 38.3 cm in 2017 and 2018 respectively. The highest fresh forage yield was determined in red clover mixtures (6519-5443 kg/da) in 2017 and 80%C+20%RC mixture (as 7137 kg/da) in 2018. Total dry matter production was ranged from 216 to 1238 and 279 to 1164 kg/da in 2017 and 2018, respectively. In pure stand chicory pasture, dry matter production was evaluated 216 kg/da in 2017 and 908 kg/da in 2018. Considering the calculated area equivalence ratios (LER) of mixed planting plots in both years and in all forms, it was determined that all mixtures were superior to plain plantings (LER≥1).

Moth bean (Vigna aconitifolia): a minor legume with major potential to address global agricultural challenges.

Moth bean (Vigna aconitifolia) is an orphan legume of Vigna genus, exhibiting wide adaptability and has the potential to grow well in arid and semi-arid areas, predominantly across different eco-geographical regions of Asia, particularly the Indian subcontinent. The inherent adaptive attributes of this crop have made it more tolerant towards a diverse array of abiotic and biotic stresses that commonly restrain yield among other Vigna species. Additionally, the legume is recognized for its superior nutritional quality owing to its high protein content as well as amino acid, mineral and vitamin profile and is utilized as both food and fodder. Moth bean can play a vital role in sustaining food grain production, enhancing nutritional security as well as provide a source of income to resource-poor farmers amid rise in global temperatures and frequent drought occurrences, particularly in rain-fed cropping systems which accounts for about 80% of the world's cultivated land. However, this minor legume has remained underutilized due to over-exploitation of major staple crops. With the exception of a few studies involving conventional breeding techniques, crop improvement in moth bean for traits such as late maturity, indeterminate growth habit, shattering and anti-nutritional factors has not garnered a lot of attention. Recent advances in sequencing technologies, modern breeding approaches and precision phenotyping tools, in combination with the available crop gene pool diversity in gene banks, can accelerate crop improvement in moth bean and lead to the development of improved cultivars. Considering the recent surge in awareness about the development of climate-smart crops for sustainable agricultural future, collective effort towards effective utilization of this hardy, neglected legume is the need of the hour.

Challenges and Opportunities for Cover Crop Mediated Soil Water Use Efficiency Enhancements in Temperate Rain-Fed Cropping Systems: A Review

Soils are at the nexus of the atmospheric, geological, and hydrologic cycles, providing invaluable ecosystem services associated with water provision. The immeasurably vital role of water provision is of urgent concern given the intertwined and interdependent challenges of growing human populations, increased agricultural demands, climate change, and freshwater scarcity. Adapting temperate rain-fed cropping systems to meet the challenges of the 21st century will require considerable advancements in our understanding of the interdependent biophysical processes governing carbon and soil-water dynamics. Soil carbon and water are inextricably linked, and agricultural management practices must take this complexity into account if crop productivity is to be maintained and improved. Given the widespread, intensive use of agricultural soils worldwide, it stands to reason that readily adaptable crop management practices can and must play a central role in both soil carbon and water management. This review details challenges and opportunities for utilizing cover crop management to enhance soil carbon stocks and soil water use efficiency in rain-fed cropping systems. A review of the current body of knowledge shows that cover crops can play a more prominent role in soil carbon and water management; however, the more widespread use of cover crops may be hindered by the inconsistencies of experimental data demonstrating cover crop effects on soil water retention, as well as cover crop effect inconsistencies arising from complex interactions between soil carbon, water, and land management. Although these gaps in our collective knowledge are not insignificant, they do present substantial opportunities for further research at both mechanistic and landscape-system scales.

Soil quality and crop productivity under 34 years old long-term rainfed rice based cropping system in an Inceptisol of sub-tropical India

IntroductionSoil quality deterioration with the introduction of modern agriculture is a major threat to agricultural sustainability and food security and the problem is more aggravated specially under rainfed agriculture. Asessment of soil quality is a tortuous task as it can not be measured directly. The objective of the present investigation was to evaluate the effect of long-term fertilization and manuring on soil quality and identify the most sensitive indicators of assessing soil quality under rainfed rice based system.MethodsSoil samples were collected from selected six treatments viz. control, 100%NPK, 50%NPK, 50%FYM, 100%FYM and 50%NPK+FYM of 34 years old long-term fertilizer experiment with rainfed rice-lentil cropping system situated at BHU Varanasi, India.Results and discussionResult revealed that continuous organic manure application along with inorganic fertilizer increased soil organic carbon by 54.1% over control treatment.Principal component analysis (PCA) was done to screen out key indicators and mean weight diameter, available Fe, available N, potentially mineralizable N, available Zn, FDA hydrolase activity and Clay were selected as key indicators of soil quality. The highest soil quality index (SQI) of 0.95 was found in 50% NPK+FYM treatment. Regression analysis showed better agreement of equivalent rice yield and SQI (0.87). Therefore, the balanced fertilization with organic and inorganic fertilizers is important for sustainability of the rainfed rice-lentil cropping system and this practice may be recommended for rainfed rice based system of Indian Inceptisol.

Climate change hotpots and their implications on rain-fed cropping system in a tropical environment

This study identifies hotspots of climate change and their implications on rain-fed cropping systems in Kyoga basin, Uganda. Based on altitude, soils and climate, we delineated three zones of the catchment as middle (Zone 1), high (Zone 2) altitudes and lowlands (Zone 3). We mapped spatio-temporal patterns of the hotspots and their implications on land suitability for rain-fed crops. We analyzed downscaled CMIP5 realizations to identify the hotspots in time slots of: 2030–2050, 2050–2070 and 2070–2090; RCP 4.5 and 8.5 scenarios and cultivation seasons (MAM and SON). We estimated the cropland climatic suitability and overlaid with the hotspots. The climate change hotspots will emerge as early as 2030–2050, increasing as time progress towards 2070–2090. Zones 2 and 3 were zones where hotspots would concentrate already at RCP 4.5. Hotspots in MAM season were less shaped by mean precipitation and temperature whereas hotspots in SON season were. The results show that the hotspots would overlap with larger areas currently suitable for sorghum, groundnuts and beans, but less for maize and sweet potato. To improved production under rain-fed system, designing appropriate adaptation strategies must be developed and areas where the detected hotspots concentrate prioritized.

Projected long-term climate trends reveal the critical role of vapor pressure deficit for soybean yields in the US Midwest

Extreme climate events including heat waves and droughts are projected to become more frequent under future climate change conditions. However, the mechanisms between soybean yields and climate factors, specifically involving variable rainfall and high heat episodes, are still unclear, particularly with respect to spatial trends in the United States (US) Midwest. A recently modified version of the model GLYCIM was used to evaluate rainfed soybean production across 12 states at a 10 km spatial resolution for three time periods (2011–2020, 2051–2060, 2091–2099) under Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5. Results showed that except for the northernmost Midwest counties, most of the current rainfed cropping system in the Midwest would suffer a 24.6–47.4 % yield loss without considering the CO2 fertility effect. Incorporating the effect of elevated CO2 showed a smaller yield loss of 11.6–29.5 %. The increased frequency of extreme degree days (EDD) or accumulation of hourly temperatures above 30 °C associated with increased vapor pressure deficit (VPD) played a key role in contributing to water deficits and resultant crop losses under these future climate conditions. Although a relatively weak relationship between summer rainfall and crop yield was observed, decreased rainfall caused VPD to increase which induced crop water deficits. These findings suggest that it is crucial to consider VPD along with high temperature and low rainfall trends simultaneously for development of potential management or breeding-based adaptative strategies for soybean.

Canola rotation effects on soil water and subsequent wheat in the Pacific Northwest USA

AbstractFarmers in Mediterranean climate regions are increasingly growing canola (Brassica napus L.) in wheat (Triticum aestivum L.)‐based systems to break soil‐borne pathogen disease cycles, control weeds, and enhance crop marketing opportunities. A 6‐year rainfed cropping systems experiment was conducted near Ritzville, Washington USA from 2015 to 2021. The objective was to compare performance of winter and spring canola, winter triticale (× Triticosecale Wittmack) (WT), and winter wheat (WW) and measure their effects on soil water dynamics and subsequent performance of spring wheat (SW). Overwinter soil water gain in canola stubble was significantly reduced compared to water gain in WT and WW stubble. The more winter precipitation, the greater the differences in soil water among treatments in early spring. There was a trend in all years for diminished overwinter soil water gain in canola stubble. Averaged over years, grain yield of SW was 1940, 2340, and 2210 kg/ha grown on canola, WT, and WW stubble, respectively (p = 0.045). Coefficients of determination from regression analysis conducted each year showed a high correlation between water content in the 180 cm profile in early spring and SW grain yield, except in one year of extreme drought. This paper provides a first report in a Mediterranean climate region of decline in wheat grain yield after canola versus after a cereal crops, primarily due to reduced overwinter soil water storage.

Impact of Farm Households’ Adaptations to Climate Change on Food Security: Evidence from Different Agro-ecologies of Pakistan

The study used data from 3298 food crop growers in Pakistan. Potential outcome treatment effects model was applied to evaluate the impact of adaptations on household food security. A household Food Security Index (FSI) was constructed applying Principle Component Analysis (PCA). Adaptation strategies employed by the farmers in response to climate change were categorised into four groups namely: changes in sowing time (C1); input intensification (C2); water and soil conservation (C3); and changes in varieties (C4). Out of 15 mutually exclusive combinations constructed for evaluation, only 7 combinations were considered for estimating the treatment effects models because of limited number of observations in other cases. Results of only two of the 7 are discussed in the paper, as the other 5 had very small number of adapters and the impact measures shown either insignificant results or had opposite signs. The first (C1234) combined all the four, while the second (C234) combined the last three strategies. The results suggest that the households which adapted to climate changes were statistically significantly more food secure as compared to those who did not adapt. The results further show that education of the male and female heads, livestock ownership, the structure of house—both bricked and having electricity facility, crops diversification, and non-farm income are among the factors, which raise the food security of farm households and their impacts are statistically significant. The variables which are significantly negatively associated with the food security levels include age of the head of household, food expenditure management, households having less than 12.5 acres of land— defined as marginal (cultivate 6.25 to 12.5 acres). Farmers of cotton-wheat, rice-wheat, and rain-fed cropping systems are found to be more food secure as compared to the farmers working in the mixed cropping systems where farm holdings are relatively small and high use of tube-well water adding to salinity of soils. It is crucial to invest in the development of agricultural technological packages, addressing issues of climate change relevant to different ecologies and farming systems; improve research-extension-farmer linkages; enhance farmers‘ access to new technologies; improve rural infrastructure; development of weather information system linking meteorological department, extension and farmers; and establishment of targeted food safety nets as well as farm subsidy programs for marginal farm households.

Effects of animal manure and nitrification inhibitor on N2O emissions and soil carbon stocks of a maize cropping system in Northeast China

The incorporation of animal manure (AM) in soil plays an essential role in soil carbon sequestration but might induce higher soil nitrous oxide (N2O) emissions. The use of nitrification inhibitors (NI) is an effective strategy to abate N2O emission in agro-ecosystems. However, very few studies have evaluated the effectiveness of applying NI under the combined application of organic and inorganic fertilizers for increasing soil carbon sequestration and reducing N2O emissions simultaneously in Northeast China. Here, a four-year field experiment was conducted with three treatments [inorganic fertilizer (NPK), inorganic fertilizer + manure (NPKM), and inorganic fertilizer with NI + manure (NPKI + M)], in a rainfed maize cropping system in Northeast China. Plots of different treatments were kept in the same locations for 4 years. Gas samples were collected using the static closed chamber technique, and nitrous oxide (N2O) concentration in gas samples was quantified using a gas chromatograph. Soil organic carbon sequestration rate (SOCSR) was calculated based on the changes in SOC from April 2012 to October 2015. Averaged over the four years, AM incorporation significantly increased soil N2O emissions by 25.8% (p < 0.05), compared to NPK treatment. DMPP (3,4-dimethylpyrazole phosphate) significantly decreased N2O emissions by 32.5% (p < 0.05) relative to NPKM treatment. SOC content was significantly elevated by 24.1% in the NPKI + M treatment than the NPK treatment after four years of manure application (p < 0.05). The annual topsoil SOCSR for the NPKM and NPKI + M treatments was 0.57 Mg ha−1 yr−1 and 1.02 Mg ha−1 yr−1, respectively, which were significantly higher than that of NPK treatment (− 0.61 Mg ha−1 yr−1, p < 0.05). AM addition significantly increased the aboveground biomass and crop yields of maize in the fourth year. Overall, combined application of DMPP, inorganic fertilizer and AM is strongly recommended in this rainfed maize cropping system, which can increase maize yield and SOC sequestration rate, and mitigate N2O emission.

Barriers and Opportunities for Sustainable Farming Practices and Crop Diversification Strategies in Mediterranean Cereal-Based Systems

Agricultural intensification negatively affects the environment through soil degradation, loss of agrobiodiversity, greenhouse gas emissions, and nutrient leaching. Thus, the introduction of crop diversification strategies and alternative management practices is crucial to re-design agricultural intensification systems. To better understand the contribution of crop diversification to more sustainable agricultural systems, an accurate evaluation of synergies and trade-offs is needed. In this context, the 5-year Horizon 2020 DIVERFARMING project aims to define sustainable, diversified cropping systems with low-input farming practices, adopting a multi-disciplinary approach. The overall objective of this study was to improve the understanding of the stakeholders’ perceptions of barriers and opportunities for implementing farming practices and crop diversification strategies in intensive rainfed and irrigated cereal-based cropping systems in Italy. Fifty stakeholders, grouped in farmers and technical agricultural advisors, field technical officers from public agricultural administrations, technical experts from NGOs with experience on farming practices, and researchers in agriculture, were engaged by public consultations to capture their practical knowledge of current farming practices for promoting suitable diversified cropping system, as alternative to agricultural intensification systems. The analysis of the stakeholders’ perceptions of barriers and opportunities to the transition of cropping systems towards diversification was done using a multi-criteria decision analysis The most important agro-environmental problem identified by the stakeholders in both the cropping systems was the loss of profitability, associated with the risk of farm abandonment, while minimum tillage, maintenance of vegetation covers, application of organic matter/manure and use of green manure, integrated pest management, and change of rotations were identified as the most adequate and effective practices to be adopted in the case study areas. Crop rotation and legumes were the most adequate diversification strategies selected for the intensive rainfed cereal-based cropping systems, while crop rotations with processing tomato and multiple cropping with short cycle maize and wheat were selected as the most appropriate alternatives for irrigated cereal-based production. Our findings highlight relevant strengths and drawbacks for the implementation of diversified cropping systems under low-input agricultural practices. An important strength is that the crop alternatives selected for the diversification are already cultivated as monocultures and are adapted to the local pedoclimatic conditions, while a major weakness is that few farmers are experts in crop diversification. These results can provide insights to support the planning of agricultural policies at different levels.