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A long-term experiment was conducted at the Central Research Institute for Dryland Agriculture for 13 years to evaluate the effect of low tillage cum cheaper conjunctive nutrient management practices in terms of productivity, soil fertility, and nitrogen chemical pools of soil under sorghum–mung bean system in Alfisol soils. The results of the study clearly revealed that sorghum and mung bean grain yield as influenced by low tillage and conjunctive nutrient management practices varied from 764 to 1792 and 603 to 1008 kg ha−1with an average yield of 1458 and 805 kg ha−1over a period of 13 years, respectively. Of the tillage practices, conventional tillage (CT) maintained 11.0% higher yields (1534 kg ha−1) over the minimum tillage (MT) (1382 kg ha−1) practice. Among the conjunctive nutrient management treatments, the application of 2 t Gliricidia loppings + 20 kg nitrogen (N) through urea to sorghum crop recorded significantly highest grain yield of 1712 kg ha−1followed by application of 4 t compost + 20 kg N through urea (1650 kg ha−1) as well as 40 kg N through urea alone (1594 kg ha−1). Similar to sorghum, in case of mung bean also, CT exhibited a significant influence on mung bean grain yields (888 kg ha−1) which was 6.7% higher compared to MT (832 kg ha−1). Among all the conjunctive nutrient management treatments, 2 t compost + 10 kg N through urea and 2 t compost + 1 t Gliricidia loppings performed significantly well and recorded similar mung bean grain yields of 960 kg ha−1followed by 1 t Gliricidia loppings + 10 kg N through urea (930 kg ha−1). The soil nitrogen chemical fractions (SNCFs) were also found to be significantly influenced by tillage and conjunctive nutrient management treatments. Further, a significant correlation of SNCF with total soil nitrogen was observed. In the correlation study, it was also observed that N fraction dynamically played an important role in enhancing the availability pool of N in soil and significantly influenced the yield of sorghum grain and mung bean. [ABSTRACT FROM AUTHOR]

A long-term experiment was conducted to evaluate the effect of integrated use of organic and inorganic sources of nutrients on soil quality and its relation to finger millet yield under two predominant crop rotations viz., groundnut–finger millet and finger millet monocropping in hot moist semiarid rainfed Alfisol soils in South India. Two experiments were laid out separately for each cropping system in a randomized complete block design with five treatments individually with FYM and maize residue-based combinations viz., Control (T1), FYM @ 10t ha−1or Maize residue (MR) @ 5t ha−1(T2), farm yard manure (FYM) @ 10t ha−1or Maize residue (MR) @ 5t ha−1 + 50% RDF (Recommended Fertiliser Dose) N, P2O5& K2O (T3), FYM @ 10t ha−1or Maize residue (MR) @ 5t ha−1 + 100% RDF N,P2O5& K2O (T4), Recommended N, P2O5& K2O (T5). Thus, four sets of nutrient management systems were evaluated. The results showed that farm yard manure or maize residue application in combination with recommended dose of fertilizer significantly improved the soil physical, chemical, and biological properties compared to control and application of inorganic fertilizers alone. Based on evaluation of 19 soil quality parameters under each of the four nutrient management systems, the common key soil quality indicators emerged out were: organic C (OC), available nitrogen (N), available sulfur (S), and mean weight diameter (MWD) of soil aggregates. A significant correlation between the finger millet yield and the relative soil quality indices (RSQI) indicates the importance of soil quality in these semiarid Alfisol soils. The results and the methodology adopted in the present study could be of importance in improving the soil quality not only for the region of the study, but also in other identical soils and cropping systems across the world. [ABSTRACT FROM AUTHOR]

To identify the best combinations of micronutrient-based fertilization treatments in terms of crop yield and nutrient uptake, three field experiments with greengram−fingermillet as the test sequence with 12 treatments on micronutrient-based fertilization [with recommended nitrogen (N)−phosphorus (P)−potassium (K) fertilizer] were conducted during 2005 to 2007 in a semi-arid Alfisol at Bangalore. The effects of treatments on available soil and plant uptake of nutrients [N, P, K, sulfur (S), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), and molybdenum (Mo)] and yield of crops were assessed based on standard analysis of variance procedure. Using the relationships of yield with soil and plant nutrient variables, regression models of yield through soil and plant variables were calibrated and effects of variables on crop yields were assessed. The models gave high and significant yield predictability in the range of 0.87 to 0.98 through different variables. The model of plant uptake through soil nutrients indicated that soil S, Fe, and Zn had significant positive effects, whereas soil N, K, B, and Mo had negative effects on plant nutrient status in greengram. Similarly, soil P, Mn, and Zn had significant positive effects, whereas soil N, K, and Fe had negative effects on plant uptake of nutrients in fingermillet. Based on a relative efficiency index (REI) criteria, T2 for plant uptake and T12 for maintaining soil nutrients were found to be superior in greengram, whereas T2 for plant uptake and T8 for maintaining soil nutrients were found to be superior in fingermillet over years based on REI. The combined REI over soil and plant nutrients for both crops indicated that application of T8 for greengram and T2 for fingermillet could be prescribed for attaining maximum plant uptake of nutrients and productivity of crops in sequence, apart from maintaining maximum soil fertility of nutrients under semi-arid Alfisols. [ABSTRACT FROM PUBLISHER]

Low productivity and cultivation of low value crops in the Indian semi-arid tropics (SAT) is the main cause for poor farm-based livelihoods. Poverty leading to low risk-taking ability of farmers and production related constraints like widespread multi-nutrient deficiencies are major stumbling blocks for shifting to high value agriculture. Realizing the need to support poverty-entrapped smallholders to connect to markets, the government of Karnataka state in India supported market-led shift to high value agriculture through a consortium of technical institutions and convergence of agricultural schemes. New widespread deficiencies of secondary and micronutrients like sulfur (52% farms), zinc (55%) and boron (62%) along with earlier known deficiencies of nitrogen (52%) and phosphorus (41%) were identified as main constraints for realizing productivity potential and a threat for sustainability. Policy supported initiative during 2011/12 showed more economic returns with diversified high value crops and strengthened 0.23 million smallholders. On-farm evaluations of soil test-based nutrient balancing to tomato, okra, brinjal, chilies, onion, cabbage and beans increased productivity by 5 to 58% over the farmers' practice of adding macronutrients only. Small additional cost (' 770 to 1520 per ha) of balanced nutrition significantly increased additional benefits (' 5300 to 74,000 per ha) with fairly high cost-benefit ratio (1:4 to 1:82). Substantial returns enhanced risk-taking ability of smallholders to manage productivity constraints in future by themselves. Results showed that initial little investments in science and market-led social assistance programs should be a way forward for mainstreaming poverty-entrapped smallholders in other parts of SAT. [ABSTRACT FROM AUTHOR]

• Spatial variability/trends of Dry Spell Index (DSI) across rainfed regions in India. • Dry spells had higher significance on rainfed crops compared to total rainfall. • Response of major kharif rainfed crops' yield to DSI was quantified. • Identification of districts with higher yield reduction in crops due to dry spells. • Quantification of yield loss caused by dry spells in the vulnerable districts. The dry spells and rainfall deficit within crop season, play vital role in determining productivity of rainfed crops. Dry Spell Index (DSI) was formulated to quantify cumulative impact of dry spells during kharif season (Jun-Sep) on major rainfed crops of India. District-wise variability of DSI were analyzed across rainfed regions of India using rainfall data of 1636 stations. Comparison of DSI with Standardized Precipitation Index (SPI), hitherto, a widely used drought index showed that, central and eastern Karnataka, northern Rajasthan and western Gujarat are becoming wetter in terms of total seasonal rainfall as indicated by SPI, and becoming drier in terms of total dry spell duration within the season as per DSI. The impact of DSI on yield of major rainfed crops viz. , cotton, groundnut, maize, pearl millet, pigeon pea and sorghum were estimated. The analysis showed that, the impact of dry spells integrated in form of the DSI on yields of six major rainfed crops was higher in comparison to total rainfall indicated by SPI for six major rainfed crops in India. Groundnut and pearl millet crops experienced higher duration of dry spells in comparison to other crops. The productivity of all the crops was significantly influenced by DSI across more than 65% growing regions. The yield loss was about 75–99% in 24% of sorghum, 23% of groundnut and 13% of pearl millet and it was about 50–74% in 44% of cotton, 24% of groundnut, 17% of maize, 16% each of pearl millet & sorghum and 12% of pigeon pea growing regions. We also found that by minimizing the cumulative impact of dry spells, yield can be increased twice in more than 55%, 49% and 42% areas of pearl millet, pigeon pea and groundnut growing regions, respectively. This study will help developing adaptation strategies to sustain crop production in rainfed regions of India. [ABSTRACT FROM AUTHOR]

This article examines the potential of conservation agriculture (CA) in rainfed areas particularly in the arid and semi-arid regions of the Indian subcontinent. The CA practices under different types of rainfall, soil and production system were identified based on the analysis of studies undertaken in different agro-climatic regions of India. The net benefits from different suggested CA practices were estimated at current prices for the year 2010 based on the results of long-term experiments conducted at the Central Research Institute for Dryland Agriculture, Hyderabad, India and centres of its All-India Coordinated Research Project on Dryland Agriculture, which ranged from Rs 325 to 18,000 ha-1. The capital requirement of various CA practices was also estimated. The analysis shows that CA in its broader context not only improves soil health but also gives higher net returns per unit of land to the farmers. However, the CA practices need to be adopted selectively in different rainfall, soils and agro-ecological situations. The advantage of CA practices can be availed in rainfed agro-ecology, if practised appropriately over long-term basis. Higher carbon sequestration through CA practices may also give additional benefits in terms of carbon emission reduction, if made easily tradable in future. However, for promotion of CA practices across diverse agroecologies, appropriate policy, and institutional and technology support would be a prerequisite. [ABSTRACT FROM AUTHOR]