Long term evaluation of reduced tillage and low cost conjunctive nutrient management practices on productivity, sustainability, profitability and energy use efficiency in sorghum (Sorghum bicolor (L.) Moench) - mung bean (Vigna radiata (L.) Wilczek) system in rainfed semi-arid Alfisol

Abstract

A long term experiment was conducted at Central Research Institute for Dryland Agriculture for 14 years to evaluate the effect of low tillage and low cost conjunctive nutrient management practices in terms of productivity,sustainability, profitability and energy use efficiency in sorghum-mung bean system in rainfed semi-arid tropical Alfisol. Results of the study revealed that of the tillage practices, conventional tillage (CT) recorded 11.0% higher yields (1534 kg/ha) over the low tillage (LT) (1382 kg/ha) practice. Among the conjunctive nutrient management treatments, the application of 2 t Gliricidia loppings + 20 kg N through urea to sorghum crop recorded significantly highest grain yield of 1712 kg/ha followed by application of 4 t compost + 20 kg N through urea (1650 kg/ha) as well as 40 kg N through urea (1594 kg/ha). As in case of sorghum, CT showed a significant influence on mung bean grain yield (888 kg/ha) which was 6.7% higher compared to LT (832 kg/ha). Application of 2 t compost + 10 kg N through urea and 2 t compost + 1 t Gliricidia loppings performed significantly well and recorded higher mungbean grain yields of 960 kg/ha. In case of mung bean, the long-term trends revealed that, the performance of minimum tillage on an average, was near to that of conventional tillage with slight fluctuation depending upon the rainfall distribution during the cropping season. In both the crops, conventional tillage recorded significantly higher net returns compared to low tillage. In case of Sorghum, net returns obtained were significantly higher with 4 t compost + 20 Kg N/ha through urea (T3) (Rs.` 30,262). The benefit-cost ratio (BCR) in sorghum crop was significantly higher (3.0) with application of 40 kg N through urea alone followed by 2 t Gliricidia loppings + 20 kg N through urea (2.77). Highest BCR (4.02) was observed with application of 2 t Gliricidia loppings + 20 kg N through urea under minimum tillage followed by recommended nitrogen dose of 40 kg/ha (through inorganic fertilizer) and application of 2 t compost + 10 kg N through urea (3.97) in mung bean. Low tillage recorded higher energy use efficiency (10.16, 5.05) compared to conventional tillage (7.21, 3.36) in case of Sorghum and mung bean, respectively.