Compartmental bunding (CB) and improved chickpea varieties were evaluated in ten farmers' fields during rainy-winter (kharif-rabi) seasons of 2012-13 in Vertisols at Bellary, India. Adopting improved chickpea varieties of BGD103 and JG11 during winter season increased the grain yields from 12.5 to 15.9%, respectively over locally cultivated A1 variety. The CB that was laid out during July (rainy season) conserved rainwater in-situ and further increased the grain yield of chickpea up to 36.7% in BGD103 and 43.9% in JG11. The increase in grain yield from 24.2% (JG11) to 27.8% (BGD103) indicates that CB is effective for in-situ rainwater conservation and improving profile soil moisture in Vertisols. However technology gap during study period was higher compared to extension gap and it was attributed to drought situation with only 81.2% of mean annual rainfall. Technology index was higher in this study and varied from 48.3% (Cultivation of BGD103 variety with CB) to 60.6% (Cultivation of JG11 variety without CB) indicating that technology index can be reduced and chickpea yields can be increased and sustained with adoption of improved chickpea production technologies including in-situ rainwater conservation practices at farmers fields. Correlation studies also indicate that grain weight, stover weight and total dry matter production per plant ultimately determine the chickpea grain and stover yields in the Vertisols of Bellary region during winter season. Higher gross and net returns with greater B:C ratio was observed with layout of farmers fields with CB and cultivation of JG11 variety.

No abstract

Farmland tree cultivation is considered an important option for enhancing wood production. In South India, the native leaf-deciduous tree species Melia dubia is popular for short-rotation plantations. Across a rainfall gradient from 420 to 2170 mm year–1, we studied 186 farmland woodlots between one and nine years in age. The objectives were to identify the main factors controlling aboveground biomass (AGB) and growth rates. A power-law growth model predicts an average stand-level AGB of 93.8 Mg ha–1 for nine-year-old woodlots. The resulting average annual AGB increment over the length of the rotation cycle is 10.4 Mg ha–1 year–1, which falls within the range reported for other tropical tree plantations. When expressing the parameters of the growth model as functions of management, climate and soil variables, it explains 65% of the variance in AGB. The results indicate that water availability is the main driver of the growth of M. dubia. Compared to the effects of water availability, the effects of soil nutrients are 26% to 60% smaller. We conclude that because of its high biomass accumulation rates in farm forestry, M. dubia is a promising candidate for short-rotation plantations in South India and beyond.

No abstract