Mulching with vegetative materials is a highly beneficial and widely-investigated agro-technique in rainfed areas but the adoption of this practice has been constrained due to non-availability of mulch biomass locally. Live mulching with fast-growing annual green manure legumes like sunnhemp ( Crotalaria juncea) or prunings of Leucaena leucocephala grown as hedge rows can be done for moisture conservation as well as nutrient cycling in the maize-wheat cropping system, which is predominantly followed in the high rainfall sub-mountainous region of north-western India. A field experiment was conducted at Selakui, Dehradun during 2000-2004 to study the effect of legume mulching, viz. in situ grown sunnhemp and Leucaena prunings, along with varying N levels, viz. 0, 30, 60 and 90 kg N ha -1 (to maize), and 0, 40 and 80 kg N ha -1 (to wheat) on productivity, soil moisture conservation and soil physico-chemical properties. Intercropped sunnhemp added 0.75-1.45 t dry matter and 21.6-41.3 kg N ha -1 at 30-35 days, while Leucaena twigs added 1.89-4.15 t dry matter and 75.2-161.3 kg N ha -1 at 60-65 days of maize growth. Live mulching with sunnhemp or Leucaena biomass improved soil moisture content at maize harvest (+1.15-1.57%) and crop productivity by 6.8-8.8% over no mulching. Combined use of both the mulching materials was more effective in improving the soil moisture content (+2.08-2.29%) and grain yield (15.1%) over their single application. Response of maize to N fertilizer application was significant up to 90 kg N ha -1, and it was relatively more pronounced under the mulching treatments. Residual effect of mulching on wheat showed an increase in yield of 10.2% with sunnhemp or Leucaena, and 27.9% with sunnhemp+ Leucaena. There was an improvement in organic C and total N status of soil, and a decrease in bulk density associated with an increase in infiltration rate due to mulching at the end of 4 cropping cycles. It was concluded that legume mulching is a highly beneficial practice for enhanced moisture and nutrient conservation, leading to increased productivity and soil health of maize-wheat cropping system under Doon valley conditions of north-western India.
