Production efficiency of conservation measures in medium-deep black soils of south-eastern Rajasthan

Three conservation measures viz. contour furrows (CF) at 6 m horizontal interval, Raised and sunken beds (RSB) with 6.6 m bed width and 15 cm elevation difference and conservation bench (CBT) terracing with 2:1 contributing and receiving area were investigated for five growing seasons for their production efficiency. The cropping systems evaluated were sorghum + pigeon pea intercropping in control plots, and either sorghum + pigeon pea or soybean on raised bed, inter furrows and CBT slopes. Either gram or mustard was sown in sunken or terraced benches. Averaged over four years cropping season surface runoff from untreated sorghum + pigeon pea intercropping was about 24% of rainfall which reduced to 20.5, 15.8 and 4.2% with CF, CBT and RSB respectively. Soil loss also followed similar patterns as the recorded soil loss values reduced from about 7 t ha^-1 to 5.1, 3.3 and 0.6 t ha^-1 under CF, CBT and RSB plots respectively. Effect of conservation measures on crop performance varied with monsoon behavior in different years. Sorghum grain equivalent (SGE) yield improved by 26, 25 and 19% over control under RSB, CF and CBT measures with sorghum + pigeon pea (CF) and sorghum + pigeon pea chickpea (RSB and CBT) cropping systems. The cost benefit analysis shows that overall CF was the most cost effective and remunerative conservation measure for both sorghum + pigeon pea and soybean cropping with a B:C ratio of 1.95. However, for promoting crop diversification RSB or CBT are potential measures for <1% and >1% slopes respectively.