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Land and water management interventions are key to achieving sustainable intensification in the drylands. This study explores opportunities for doing so in Vertisols and Alfisols using 34-year (1976–2009) long-term experimental data. Four cropping systems were evaluated in each soil types with two land form management interventions, i.e., raised beds and flat beds. Surface runoff generated and soil water content in each system were monitored along with crop yields. In Vertisols, maize-chickpea sequential cropping and sorghum+pigeon pea intercropping on raised beds representing an improved practice was followed for 34 years (1976–2009). Sole chickpea and sole sorghum were grown on flat beds as a traditional system during the same period. In Alfisols, groundnut/pigeon pea intercrop and sole sorghum were grown for 5 years (2002–2006) and sorghum/pigeon pea intercrop and sole castor were grown for 3 years (2007–2009) under raised bed and flat bed conditions, respectively. The use of improved practices in Vertisols produced 3–5 times higher yield compared to traditional practices with net returns estimated at US$ 800–1300/ha/year compared to US$ 90–350/ha/year under the traditional practice. Despite growing an additional crop, chickpea yield under the improved practice was close to the yield obtained from the traditional practice. In Alfisols, raised beds improved crop yields by 15–20% compared to the flat bed method, leading to an additional net return of US$ 80–100/ha/year. Sorghum/pigeon pea intercrop was found to be superior followed by sole castor, groundnut/pigeon pea intercrop and sole sorghum in Alfisols. Hydrological monitoring revealed opportunities to harvest surface runoff, especially in Alfisols, by building low-cost rainwater harvesting structures that can provide life-saving irrigation during dry spells. An interpretive machine learning (IML) approach was used to estimate four response variables (Sorghum equivalent yield; Net Income; Technical Water Productivity, and Economic Water Productivity) using five different predictor variables (i.e., cropping systems, land form, soil order, effective rainfall (R eff = rainfall-runoff), and water regimes (dry, wet, and normal). Results showed that cropping system is the highest mean feature importance for all the productivity parameters followed by effective rainfall. This paper also discusses soil water dynamics, production functions and technical and economic water productivity which could aid in resource optimization and in developing strategies for land, water and crop management interventions with the aim of bridging yield gaps in the semi-arid tropics. • Raised beds coupled with double cropping in Vertisols holds 3–5 times higher production potential than traditional practices. • Chickpea yields from double cropping equal yields obtained from sole chickpea in Vertisols. • Sorghum/pigeonpea intercropping and sole castor were found most suitable in Alfisols in terms of productivity and income. • Surface runoff generated in Alfisols was 16–17% of the total rainfall, offering good scope for rainwater harvesting. [ABSTRACT FROM AUTHOR]

Jatropha curcas referred as a 'wonder plant' with low water requirement, which can be cultivated on wastelands in dry tropical conditions to provide oil seeds for biodiesel without competing for prime cropland. However, results from experiments and case studies in semi-arid tropical locations in India indicated that evapotranspiration ( ET) demand for Jatropha ranges between 750 and 1000 mm under optimal conditions. Jatropha extracted water from soil layer 150 cm below with transpiration requirements of 600-800 mm with increasing age. The yield potential of current genotypes is low (2-3 ton/ha) for realizing the potential of Jatropha cultivation on wastelands subject to limited availability of nutrients and water. Jatropha curcas is drought tolerant, but contrary to belief, it is not a crop that requires less water: in fact, it requires 750-1000 mm water to achieve economic production. However, Jatropha curcas demonstrated good potential for enhancing green water use efficiency without adversely affecting the blue water component, and for promoting crop management options facilitating carbon sequestration and nutrient recycling when grown on degraded lands. Improved cultivars of Jatropha curcas with synchronized flowering to enable mechanical harvesting, along with improved land and water management, are needed for harnessing the potential of Jatropha as a commercially viable biofuel crop. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Summary Considering the importance of sustainable production practices with greater resource use efficiency, a study was conducted during 2009–12 to understand the soil properties, crop yield, and economics as affected by the integrated crop management (ICM) practices under the Bhoochetana (soil rejuvenation) program in Karnataka, India. Results from 3776 crop-cutting studies on different crops (cereals, pulses, and oilseeds) revealed that there is a vast spatial variability in case of various soil nutrients across different taluks of Karnataka. Balanced fertilizer application, both in rainfed and irrigated areas, directly influenced crop yields. Yields of cereals, legumes, and oilseeds were 3590, 1400, and 2230 kg ha −1 with improved management practices as compared to 2650, 1030, and 1650 kg ha −1 with conventional farming practices, respectively. Average net income estimated from conventional farming was Rs. 26,290 ha −1 , while it was Rs. 35,540 ha −1 from improved management practices, which indicated that ICM practices resulted in an additional 35% income. The oilseeds performed better in terms of achieving higher net income and benefit–cost ratio while the cereals and legumes also have shown significant improvement in yield compared to the yields from conventional farming practices. The detailed findings on soil properties, yields of crops, and economics suggested that there is a vast potential for crop productivity improvement through ICM practices across different soil types and rainfall zones of Karnataka, India. [ABSTRACT FROM AUTHOR]