Rainfed System Research Articles

Cover crops and deep‐soil C accumulation: What does research show after 10 years?

AbstractThe extent to which cover crops (CCs) accumulate soil organic carbon (SOC) in the entire soil profile is still unclear. We measured SOC, permanganate oxidizable C (POX‐C), and particulate organic matter (POM) concentrations down to 60‐cm soil depth in early [2–3 week before corn (Zea mays L.) planting]‐ and late‐terminated (at corn planting) winter rye (Secale cereale L.) CCs in rainfed and irrigated no‐till continuous corn systems in the U.S. Corn Belt after 10 years. CCs increased SOC stock and SOC, POX‐C, and POM concentrations but only in the irrigated system in the upper 5‐cm depth. Late‐terminated CC increased SOC concentration by 4.710 ± 3.501 g kg−1 and accumulated SOC at 0.207 ± 0.145 Mg C ha−1 year−1. It increased POX‐C and POM concentrations, on average, by 1.194 times. CCs likely increased SOC in the irrigated system by producing more biomass (2.247 ± 0.370 Mg ha−1) than in the rainfed system (0.949 ± 0.338 Mg ha−1). At least 2 Mg ha−1 of CC biomass may be needed to increase SOC. Because winter CCs often produce <1 Mg ha−1 of biomass when typically planted late and terminated early, extending the CC growing window by terminating CCs at or after crop planting (planting green) may boost CC biomass and SOC accumulation, although high‐C soils or Mollisols, such as our study soils (>22 g C kg−1), may limit SOC gains. We submit CCs would sequester more SOC in low‐C, eroded, and low‐fertility soils. Overall, winter rye CCs minimally alter soil C in the soil profile in no‐till continuous corn systems after 10 years.

A Case Study on Biomass Assessment in a Semi-Arid Olive Rainfed System in Morocco

Thanks to its potential life span of hundreds of years, olive can develop great biomass and sequester large amounts of carbon (C). It may therefore play a critical role in reducing atmospheric C and improving farmer livelihoods by providing additional revenue from C credits. Predicting olive’s impacts on C cycling relies on allometric models. In our specific conditions, such models reliably predicted biomass accumulation with a minimum of three dendrometric measurements: tree age, height, and diameter at 10 cm.

Sustainability of Organic Fertilizers Use in Dryland Mediterranean Agriculture

Organic fertilization is a key issue in European Union (EU) regulations, particularly in the context of promoting a circular nutrient economy, maintaining soil quality, and sequestering carbon to face climate change. In a rainfed system in Northeastern Spain, an experiment was set up (split-plot design). It included five pre-sowing N fertilization treatments: control, mineral, pig slurry, and composted sewage sludge (two rates). The average N rates were 0, 30, 141, 176, and 351 kg N ha−1, respectively. They were combined with mineral N topdressings (0, 50, and 100 kg N ha−1). Three crops were grown: barley (nine years), wheat (three years), and rapeseed (one year). In the driest years (c. 350 mm rainfall), the yields averaged 2.5, 2.0, and 1.9 Mg ha−1, respectively. The maximum yields were for barley (6.5 Mg ha−1) and wheat (5.5 Mg ha−1). The avoidance of a significant increase in soil residual NO3−-N, plus the control of soil build up of available P, micronutrients, and Cd, defines the fertilization strategies. (i) With a previous spring drought season, no fertilization is needed in the following year, if devoted to winter cereals. (ii) In rainier seasons, pig slurry or composted sewage sludge (lowest rate) applied at sowing is sufficient; however, 50 kg of mineral-N ha−1 at the topdressing can be applied. The study found that pig slurry favors K, Mg, Cu, and Zn availability, while composted sewage sludge enhances Fe availability. Although it is possible to reduce N inputs from organic fertilizers, organic C build-up will be constrained.

Crop Diversification and Fertilization Strategies in a Rainfed System with Drought Periods

Crop diversification and the reduction of nitrogen (N) inputs are key issues in the EU for more sustainable agriculture. An experiment was set up in a semiarid rainfed Mediterranean system. Our hypothesis was that these challenges could be addressed by introducing new crops and using pig slurries (PSs). The experimental factors were N fertilization at sowing (with or without PS) combined (according to a split-block design) with N fertilization as topdressing (the control, two N mineral rates, and two N rates from PS). Barley, rapeseed, and pea performances were evaluated in two different crop sequences: (i) barley–rapeseed or rapeseed–barley after a fallow season, and (ii) barley–pea or pea–barley after a fallow season followed by a non-fertilized barley crop. The results of the four-year study demonstrated that under a spring drought risk, barley performed better than peas in terms of relative crop yield maintenance. After fallow, N can be saved while maintaining the yields and total biomass of barley and rapeseed. In the second crop sequence, maximum pea and barley yields were associated with a minimum topdressing of 60 or 120 kg mineral N ha−1, respectively. However, slurry fertilization at sowing also allowed the highest yields for barley. Rapeseed and peas can be introduced to reduce N fertilization inputs. However, the obtained yield plateau for pea and rapeseed (3 and 4 Mg ha−1, respectively) and the effect of a yield spring drought on pea yields (50% reduction) might be a constraint for the success of EU policies on crop diversification.

Analysis of Management Practices and Breeders' Perceptions of Climate Change's Impact to Enhance the Resilience of Sheep Production Systems: A Case Study in the Tunisian Semi-Arid Zone.

Global climate change inflicts unambiguous risks on agricultural systems and food security. Small ruminants are known for their ability to adapt to changing environmental conditions. This paper aims to characterize sheep production systems in a vulnerable agricultural zone and the breeders' perceptions of climate change to apprehend challenges that they are confronting, and formulate resilience actions. The data analysis is based on 94 semi-structured surveys of sheep farmers carried out in the Tunisian semi-arid region. The PCA analysis results revealed three main sheep production systems. The agro-pastoral rain-fed system (AGPRF) is dominant (55%), with large farms and common pastures integrating cereals and fodder. The agro-pastoral irrigated system (AGPI: 20%) is characterized by small-area and forage irrigation (1.8 ha) and a smaller number of ewes but a greater use of animal feed supplementation. The agro-sylvo-pastoral system (AGSP: 25%) is a system where grazing is based on common lands and using tree sub-products, while the agricultural area is exclusively used to cultivate cereal crops. Sheep breeders' climate perceptions are summarized as unpredictable climate events, a decrease in precipitation, and an increase in temperature. Resilience actions principally consist of reducing flocks' numbers, using alternative local feed, fodder, and water resources, and building more shelters and planting more trees in the grazing areas. Nevertheless, cost-effectiveness should be considered in such vulnerable zones to insure the sheep production systems' sustainability.

Assessing flood risks and exploring opportunities for flood-based farming in the dry lowlands of Ethiopia

Food grown in the rainfed system in Ethiopia is frequently insufficient to meet household food needs due to recurrent drought, which causes severe food insecurity. Ethiopia’s drylands have also been hit by an increase in torrential floods. As a result, the ability to adapt to shocks and risks decreases. Despite the opportunity of highland-to-lowland to lowland connectivity, the opportunities for flood-recession farming are poorly understood. This study maps flood recession opportunities incorporating national flood occurrence information, flood images, and SMAP surface soil moisture from Soil Moisture Active Passive (SMAP) images in Omo Gibe basin and Mile sub-basin. The analysis demonstrates that during the past three decades, there have been substantial flood incidents in the country’s eastern, south-eastern, and southern regions. Notably, floods that happened in 1996, 2005, 2006, 2013, and 2018 affected 90, 91, 74, 74, and 69 locations, respectively. In 2020, flooding affected a considerable area (274 locations), which demonstrates the rise in flood hazards. Based on multi-criteria suitability analysis, about 32 million hectares of lowlands are highly suitable (61%) and moderately suitable (39%) for flood-based farming. In the Omo-Gibe and the Mile sub-basin, flood-recession zone mapping using a change detection approach revealed that Omo-Gibe basin has 107,359 ha and 29,550 ha of flood zones suitable for flood recession farming and Mile sub-basin of 8,048 ha and 88 ha, during the major and short rainy seasons, respectively. Our results highlight the extent of flood-prone areas and their suitability for flood farming and provide evidence of alternative strategies for managing flood risks. Consequently, identifying potential flood-prone areas using remote sensing technology aids decision-makers and subject-matter experts in introducing and demonstrating various types of flood-based farming. Further research is recommended to identify and validate appropriate flood farming practices under different biophysical and socio-economic contexts and explore complementary opportunities as well as support informed decision-making on flood risk management and recession flood strategies in the dry lowlands of Ethiopia.

Modelling land suitability and development potential options for irrigable and rainfed agricultural scenarios in Ethiopia

AbstractDespite being a significant sector in Ethiopia, agriculture is mainly run in rainfed system. However, it is imperative to look for irrigation systems and their suitability to the country's agriculture. The study's objectives were to (1) map areas appropriate for irrigable and rainfed agriculture and examine gaps with current active areas, (2) model possible development for irrigation and rainfed scenarios, and (3) offer evidence‐based decision support for agricultural investment. Land features, agroecology, population density, market accessibility and length of growing seasons were considered as important indicators when determining land suitability for each scenario. Geographically weighted regression was used to model these indicators. The results show that approximately 359,360 (34%) and 13,802 km2 (1.6%) are highly suitable areas for irrigation and rainfed agriculture, respectively. However, Ethiopia's production depends on areas moderately suitable for rainfed agriculture, but these areas are highly suitable for irrigation rather, indicating that it is unfortunate that the areas suitable for irrigation are used for rainfed agriculture so far. In terms of development potential, areas of approximately 71,317 (7%) and 347,435 km2 (33%) had the highest and a high irrigation potential, respectively, while areas with rainfed agriculture had approximately 33,821 (3%) and 105,013 km2 (10%) with the highest and a high development potential, respectively. These analyses suggest that the country has untapped potential for agricultural development in both scenarios, but this remains within the scope identified in this study.

Rethinking the Impact of Land Certification on Tenure Security, Land Disputes, Land Management, and Agricultural Production: Insights from South Wello, Ethiopia

Land is a precious resource in the Ethiopian highlands, where the entire agricultural system depends on rain-fed system. The resource faces multiple interconnected environmental and socioeconomic challenges. Among these, the absence of tenure security has significantly affected farmers’ willingness to adopt soil and water conservation practices (SWCPs), leading to a decline in land productivity, hindering household food security, and contributing to an increase in land-related disputes. Bearing this in mind, the government of Ethiopia (GoE) has undertaken two rounds of land certification programs in selected regions, one of which was Amhara National Regional State (ANRS). This study examined how land certification strengthens tenure security, lowers land-related disputes, motivates farmers to employ SWCPs, and raises the productivity of farm plots in Dessie Zuria and Kutaber Woredas. The research followed an exploratory survey method which utilized both qualitative and quantitative data. The survey involved purposefully selected 401 household heads. Additionally, cross sectional data were collected from various sources, including Woreda and zonal agriculture, court, land, and Natural Resource Management (NRM) offices. Quantitative data were analyzed using frequency tables, percentages, graphs, figures, cross-tabulation, and descriptive statistical methods. Meanwhile, qualitative data were transcribed, grouped, and interpreted in line with the research’s objectives. SPSS software version 26 was used for data analysis. The findings denoted a positive relationship between land certification and tenure security. Furthermore, enhanced tenure security has played a positive role in reducing land-related disputes, initiating farmers to invest in SWC practices and improving the productivity of farm plots. The research suggests the adoption of a cadastral land registration system, the encouragement of community involvement, and the enforcement of laws and bylaws. The research recommend implementation of cadastral land registration system, promote community participation, and enforcement of laws and bylaws. The work has implications for development practitioners, academia and policymakers working on land tenure, SWC practices, and food security.

Impact of biochar amendments on soil water and plant uptake dynamics under different cropping systems

AbstractApplication of biochar amendments in agricultural systems has received much attention in recent years. In this study, we assess the 5‐year impacts of biochar application on soil water and plant interactions for an irrigated fresh market tomato (Solanum lycopersicum) and a rainfed pasture (Poaceae) cropping system. In particular, we focus on three varieties of locally produced biochar from agricultural waste materials—almond shell, walnut shell, and almond pruning residues that are pyrolyzed using a mobile pyrolysis unit. We used the soil hydrological model HYDRUS‐1D to explicitly track seasonal and annual soil water fluxes through changes in water retention, drainage, evaporation, and plant water uptake under biochar application. Modeling results show that the application of biochar at 5% increased soil water availability within the top 20 cm for a rainfed system, irrespective of biochar amendment type. This is clearly indicative of higher plant water uptake and greater water use efficiency (WUE) under biochar application. In contrast, a similar biochar amendment for the irrigated system did not affect WUE, instead reducing seasonal soil evaporation loss and thereby reducing irrigation demand. In both cropping systems, year‐to‐year variability in precipitation significantly impacted the total amount of water saved under biochar application with certain amendments retaining more water than others. Given that biochar application increased water retention irrespective of cropping systems, we further used a simple approach to determine yield trade‐off, if any, between control and biochar treatments. Our economic balance clearly demonstrates that the water saved by amending soil with biochar does not offset the yield disparity if compensated with carbon credits and therefore, application of biochar should be actively considered for both its direct and indirect benefits to potential greenhouse gas mitigation (e.g., diverting orchard waste from open burning), water savings, and soil health.

Crop diversification effects on soil organic carbon and nitrogen storage and stabilization is mediated by soil management practices in semiarid woody crops

Crop diversification is a promising strategy to mitigate climate change through soil carbon sequestration while ensuring soil fertility maintenance and food security. Here, we assess the impact of different inter-cropping practices on soil organic carbon (SOC) and nitrogen (N) storage and stabilization under rainfed and irrigated semiarid conditions. Under rainfed conditions, an almond (Prunus dulcis Mill.) monocrop was compared with an almond inter-cropped with caper (Capparis spinosa) or with winter thyme (Thymus hyemalis). Under irrigated conditions, a mandarin (Citrus reticulata Blanco) monocrop was compared with a mandarin inter-cropped with an annual crop rotation (including Hordeum vulgare, Vicia sativa and Vicia faba) or with a triennial crop rotation (including Vicia faba, Portulaca oleracea and Vigna unguiculata L.). The SOC and N stocks, SOC mineralization rates, water-stable aggregates and associated OC and N contents were estimated at 0–10 and 10–30 cm depth in each monocrop and inter-cropping system after three years. Contrasting effects of inter-cropping on SOC and N stabilization were found in the rainfed and irrigated systems. The combination of inter-cropping and no tillage did not affect the SOC stocks or mineralization rates at any soil depth in the rainfed system, while it significantly increased the OC and N contents within the large macro-aggregates in the subsoil. Compared to the irrigated mandarin monocrop, the mandarins inter-cropped with the annual crop rotation showed a significant increase of 10% and 18% in the topsoil and subsoil N stocks, respectively, while the SOC mineralization rates were reduced by 30% at both soil depths. On the contrary, the topsoil SOC stock in the mandarins inter-cropped with the triennial crop rotation were reduced by 38% compared to the monocrop. Significant reductions ranging between 24% and 66% were also observed in the OC and N contents associated to the macro- and micro-aggregates in the topsoil and subsoil of both crop diversifications compared to the monocrop system. Our results highlight the potential of inter-cropping rainfed woody crops with perennials for boosting SOC and N storage and stabilization. In irrigated woody monocrops, inter-cropping with annual crop rotation schemes that include two or more leguminous and reducing tillage frequency operations seems to be more appropriate in terms of SOC and N stabilization.

Agricultural use of compost under different irrigation strategies in a hedgerow olive grove under Mediterranean conditions – a comparison with traditional systems

Abstract. Soil and water-efficient management are key factors in ensuring the olive sector's sustainable production practices. The use of compost based on olive waste (alperujo) as fertilizer could enhance ecosystem services while the need to transition to a zero-waste approach based on a circular economy is achieved. The present work includes a comparative study of the effect of alperujo compost (AC) vs. inorganic fertilization under different management systems: a traditional adult olive grove under rainfed conditions and a young hedgerow olive system, in which a factorial test of tree irrigation regimes (full, deficit and no irrigation) is implemented as well. At the hedgerow plots, the addition of AC and soil sampling time greatly impacted soil chemical parameters and, to a lesser extent, enzymatic activities, whereas irrigation regimes did not exert a marked influence. In the traditional rainfed system, the addition of AC proved to be an efficient tool for carbon sequestration. The first soil sampling revealed a clear stoichiometric relationship between soil organic matter (SOM) and the nitrogen, phosphorus and potassium (NPK) contents in both systems, whereas the correlations were weak and scarce in the second sampling at the hedgerow plots. This fact was related to the decay of the compost effect. Compost in combination with irrigation tended to trigger a certain priming effect on the native SOM with time since the carbon stocks were reduced between 6 % and 38 % from one sampling to the other in the hedgerow system, depending on the irrigation intensity. However, the deficit irrigation caused a less intense reduction of the SOM and essential nutrients representing the best alternative to maximizing the agronomic effects of the compost under a water-saving strategy. Recurrent application of compost would be necessary to maintain soil quality, especially with high tree densities. The combined management of AC and the deficit irrigation proved to be an efficient tool toward a zero-waste circular economy and a water conservation strategy.

The comparison of relationship between climate variables and rice productivity in the clustering area on Java Island, Indonesia

This study aims to compare the relationship between climate variables and rice productivity under different irrigation systems (irrigated and rainfed) in the clustering area on Java Island, Indonesia. This study used the clustering areas resulting from the previous study. The climate variables used are bias-corrected MERRA2 data from the period 1987–2017, cropped for Java Island. The rice productivity and reference evapotranspiration data used in this study are the results of the simulation of Aquacrop modeling. The result from the cluster method used tends to divide Java Island into 2 clusters with different altitudes (lowland and highland) areas. The results show that the correlation values between the precipitation variable and rice productivity from Aquacrop simulation (both irrigated or rainfed) in cluster 1 (dominated lowlands) are higher than in cluster 2 (dominated highlands), contrary to that the correlation values between the reference evapotranspiration variable with rice productivity from Aquacrop simulation (both irrigated or rainfed) are higher in cluster 2 (dominated highlands) areas, compared to cluster 1 areas (dominated lowlands). R-square values from response surface methodology (RSM) on the rainfed system in both clusters are higher than those on the irrigated system. This indicates that rainfed agriculture is highly dependent on climate variables, especially precipitation and reference evapotranspiration variables compared with the regular irrigated agricultural system. The RSM result also shows that climate variables significantly contribute to the variation of rice productivity generated by Aquacrop modeling in irrigated and rainfed systems and in all clusters.

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.

Implication of land use shifting on land degradation and restoration potential of conservation agriculture in India's North-West Himalayan region

The soil organic matter is a crucial factor in determining soil characteristics and productivity; however various land management practices degrade or aggrade the soil health. The objective of this study was to look at the influence of land-use conversion on soil health by using the concept of stratification ratio (SR) of soil organic carbon (SOC) and total nitrogen (TN) and appraise SR as a predictor of SOC and TN stock and soil health for India's North-West Himalayan region. The research is oriented toward assessing the consequences of various land use regimes' impacts on SOC and TN depth distribution, storage, and stratification and, hence, identifying appropriate sustainable tillage techniques for the region. The research was accomplished in 2020–21 in the long-term experimental plot with four land uses, namely control [natural sal forest (Shorea robusta L.), conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT)] in a rainfed system of north-western Indian Himalayas. A decrease of 79% in the mean weighted diameter of CT was observed after conversion from forest land to CT; however, the decrease was only 50% in the case of the adoption of ZT. Further, the surface soil (0–5 cm) SOC was significantly different from each other, with forest soil having the highest SOC (27.5 ± 0.21 g kg−1) and CT having the lowest SOC (11.0 ± 0.09 g kg−1). The stock of SOC and TN increased significantly with increment in soil depth, and among landuses, the highest SOM was observed with forest and the lowest with CT. Among the treatments, forest (56.56 ± 1.90 Mg ha−1) had significantly higher SOC storage than conservation agriculture (CA) (42.84 ± 0.27 Mg ha−1, ZT, and 41.41 ± 1.84 Mg ha−1, RT) and CT (41.33 ± 1.19 Mg ha−1) based on equivalent soil mass approach. For forest land use, except the surface layer (0–5:5–10), all the soil layers had SR >2, whereas, for ZT, the bottom two layers (0–5:20–25 and 0–5:25–30) had SR >2 and for RT, only the bottom layer (0–5:25–30) was having SR > 2. It was observed that the conversion of land use to CT reduced the SR of SOM drastically; however, by adopting CA, the SR had been restored to near normal in forest land use. The carbon pool index (CPI) was used to determine the effects of soil tillage and residue incorporation on soil quality improvement with respect to a sal forest. The CPI value increased significantly with an increase in soil depth for three land uses, and also, at each soil depth, the CPI followed the ZT > RT > CT trend. Thus, CA may be considered a viable alternative to CT for improving soil physicochemical parameters.

Extrinsic Motivation in Farming on Earthy Stone Land in the Binongko Island Wakatobi Regency South East Sulawesi

Coastal areas and small island communities in the Wakatobi archipelago carry out traditional agriculture. Farming is held with a rainfed system on dry land and a dry climate. This system theoretically has non-optimal productivity. Even so, farmers still farm because extrinsic motivation influences how they manage farming land. The productivity of their farms is relatively able to meet the needs of farmers. This study aims to determine extrinsically motivations attached to the traditional agricultural systems of the Binongko community in the Wakatobi Islands. The research lasted eight months, from June 2019 to February 2020. The research data was collected with the triangulation method by observation, interviews, and literature study. The research informants were determined purposively with a chain information collection system. The data were analysed qualitatively using a phenomenological approach. Based on the results of this study, it is known that the Binongko Island community has an extrinsic motivation attached to traditional farming systems, namely, to obtain agricultural products economically, socially, and ecologically. In addition, farmers are also extrinsically motivated by the support from the government. These local wisdom techniques are implemented starting from land preparation and clearing, planting, maintenance, harvesting and post-harvesting.

Impact of Climate Change on Crop Water Requirement in Kamala River Basin of Nepal

The future climate which has crucial role of any hydrological events that occurs within basin will have more uncertainty. Changing the climatic variables, the water balance of the basin will more unpredictable. Not only will climatic parameter changes but also adversely affected the water management within the basin. In this study, an attempt has been carried out to compare the future River flow of Kamala basin and future water demand of Kamala irrigation command area. The CROPWAT and AQUACROP model, based on climatic, soil and crop data, was used to estimate the future Crop Water Requirement (CWR), Irrigation Water Requirement (IWR) and Biomass yield. The hydrological station, because not exist within basin, was not possible to simulate the future river flow of the Kamala basin using any hydrological model. Therefore, the WECS method is simply used to forecast the future monthly flow of Kamala River. The two emission scenarios, ssp245 and ssp585 were conducted based on cropping intensity 170% and 300 % and IWD for each sub-scenario over 12 months was estimated. For the first sixth months, IWR is increased in the future period as maximum and minimum temperature increases and the IWR for monsoon season is less required due to increases in precipitation and again for the post-monsoon season, IWR is increased compared as historical IWR. The highest irrigation water requirement occurs in March month under ssp245 and ssp585 and CI 300%. Whereas, July and August months have the lowest irrigation water demand under ssp245 and ssp585 scenarios. Based on the finding, the production of crop with irrigation system has higher than rainfed system. For paddy, the rainfed system produced dry yield of 6.58 ton/ha whereas, dry yield of irrigated field has 7.05 ton/ha. The future river flow is insufficient to meet the irrigation water demand in first five months in near future under both ssp245 and ssp585 scenarios. The magnitude of deficiency in ssp585 is comparatively higher than in ssp245. As a result, all of these findings suggest that the crop waterrequirement of KIP is insufficient in the future to provide a year-round irrigation system.

Nitrogen fertilization split in green corn under rainfed system

The objective of this work was evaluating the nitrogen fertilization splitting on the performance of green corn, grown in rainfed system. The experiment was carried out in Forquilha, Ceará state. Two varieties of corn (Sweet and Gorutuba) were used in the experiment, grown in five types of nitrogen fertilization in the crop cycle (one; three; six; nine and twelve applications). The variables evaluated were: plant height, stem diameter, number of leaves of the plant, plant fresh mass, plant dry mass, ear mass plant-1, marketable ear mass plant-1, marketable husked ear mass plant-1, marketable unhusked ear mass plant-1, number of ear plant-1, number of marketable ear plant-1, length of husked marketable ear, length of marketable unhusked ear, diameter of marketable husked ear, diameter of marketable unhooked ear, number of rows marketable ear-1 and number of grains row-1 of marketable ear. The data were subjected to analysis of variance by the F test (P < 0.05) and the treatment means were compared by the test of Tukey (P < 0.05) and subjected to regression analysis. It was observed that the split of nitrogen fertilization promoted the development of the two varieties of corn studied. It was found that the split, performed in six applications, provided greater vegetative and reproductive development of the corn varieties.

System based phosphorus management improved the productivity, profitability and nutrient uptake of rainfed rice (Oryza sativa L.) - greengram (Vigna radiata L.) cropping system

The effect of system based phosphorus management on crop productivity, profitability and nutrient uptake of rainfed rice-greengram cropping system was studied under medium land situation at ICAR-NRRI, Cuttack, Odisha. The experiment was carried out in both kharif and rabi season of the years 2019-20 and 2020-21. The experiment was laid out in a split plot design with four nutrient management practices in rice viz. recommended dose of fertilizer (RDF), RDF + 25% additional phosphorus(P) through FYM, RDF + 25% additional phosphorus(P) through fertilizer and 75% of RDF (RDF75) in main plots and five nutrient management practices in greengram viz. Control, RDF, RDF + PSB inoculation (RDF+ PSB), RDF + Foliar spray of 2% DAP (RDF + FS) and RDF + PSB inoculation + Foliar spray of 2% DAP (RDF + PSB + FS) in subplots and replicated thrice. Effect of system based phosphorus management had significant effect on productivity, profitability and nutrient uptake by the system. Application of 25 % additional phosphorous to rice through fertilizer improved the rice equivalent yield (REY) and P uptake of the rice - greengram system by 6.6 and 7.1% compared to the application of recommended dose of phosphorus to rice. The same treatment also resulted in significantly highest net returns and B:C ratio from the cropping system compared to all other treatments including application of 25% additional phosphorus through FYM. However, application of PSB and foliar spray of 2% DAP along with recommended dose of phosphorus to greengram improved the REY and P uptake of the system to the tune of 23.4 and 21.3%, respectively, compared to non fertilized plots where as 6.2 and 9.6%, respectively, over recommended dose of P to greengram with highest net return and B:C ratio. Further, application of 25% additional phosphorus through FYM or fertilizer along with RDF to rice followed by application of PSB and foliar spray of 2% DAP along with RDF to greengram produced the highest grain and straw yield, nutrient uptake, gross return, net return and B:C ratio.

Can Increase in Productive Efficiency Mitigate Climate Impact on Agriculture in the South Asian Region?

South Asia is still a predominantly agrarian society, where a majority of the population is dependent on agriculture for their livelihoods. Rural poverty is higher than urban poverty, reflecting the heavy dependence on natural resources that are directly influenced by changes in weather and climate. The majority of South Asian agriculture is still based on a rain-fed system and is directly affected by climate change. The impacts of climate change on food production and food security in South Asia will vary by country, with many countries experience a decline in productivity. This paper examines the impact of climate change on agricultural production and the role of efficiency increment as an adaptation strategy for climate change in South Asia. First, a stochastic production frontier was estimated for South Asian agriculture. Then the climate change impact on agricultural production was predicted for 2050 using the estimated frontier. Finally, this paper assessed whether improvements in technical efficiency can offset the effect of climate change in this region. For this, a true random effect stochastic frontier with an exponentially distributed time varying inefficiency model was estimated. For this analysis, secondary data from the World Bank, Food and Agriculture Organization (FAO) and International Labour Organization (ILO) were used. Output of gross production values were calculated using agricultural land use, pesticide use, total labour use, total fertilizer use data with climate normals pertaining to eight countries in the south Asian region were collected from 1991 to 2017. The results indicate that with the expected climate change by 2050, Bhutan, Nepal and Pakistan will have a positive impact on their agricultural production while Bangladesh, India, Maldives and Sri Lanka will have a negative impact on their production. Overall technical efficiency of agricultural production in South Asia is 75.12% while individual countries show varying levels of technical efficiency, viz., Bangladesh 69.41% Bhutan 85.64%, India 71.83%, Maldives 44.91%, Nepal 82.78%, Pakistan 85.68%, and Sri Lanka 75.89% of efficiency. Prediction using the estimated model and efficiencies show that the negative impacts of climate change could be mitigated if these countries try to increase their levels of productive efficiencies such as following dissemination of technology, crop protection, training and development strategies, crop insurances to increase agriculture production.&#x0D; Keywords: Panel data, South Asia, Stochastic frontier analysis, Technical efficiency, True random effect

The Water Footprint of Biodiesel Produced from Sunflower in South Africa

The use of feedstock crops for the production of biodiesel suggests that biodiesel production may have a major impact on the scarce freshwater resource in South Africa. This paper aimed to assess the green plus blue water footprints (WFgreen+blue) of biodiesel produced from sunflower in South Africa using the Global Water Footprint Standard approach. The green (WFgreen) and blue water footprint (WFblue) at the farm level were assessed for sunflower grown under the rain-fed and irrigation production system respectively. The results show that 2617 m3 and 2477 m3 are required to produce 1 ton of rain-fed and irrigated sunflower respectively. At the processing level, about 7.12 L of blue water is required to produce 1 L of biodiesel from sunflower. The WFblue at the processing stage of biodiesel produced from irrigated sunflower was 1.01 m3/GJ, compared to 1.15 m3 m3/GJ from rain-fed sunflower. The WFgreen+blue of biodiesel produced from irrigated and rainfed sunflower was 2477 and 2617 m3/ton, respectively. WFgreen was the largest, accounting for about 59% and 99% for biodiesel produced from irrigated and rain-fed sunflower, respectively. It was further found that water consumption at the farm level accounted for about 99% of the WFgreen+blue of biodiesel in both production systems. Management practices that improve water use efficiency at the farm level may help to lower the WFgreen+blue of biodiesel. Interestingly, the WFgreen+blue is lower for biodiesel produced from irrigated sunflower than for rainfed sunflower. The blue water scarcity assessment showed that blue water scarcity is low during the period when sunflower requires water. As such, purely from a water use perspective, irrigated sunflower production in the Orange Riet Irrigation Scheme may be considered sustainable.