Water, Nutrient, and Energy-use Efficiencies of No-till Rainfed Cropping Systems with or without Residue Retention in a Semi-Arid Dryland Area

Abstract

No-till rainfed cropping systems are being considered by farmers to make farming more profitable by reducing production costs, thereby enhancing resource-use efficiency. Field studies were conducted at the Indian Agricultural Research Institute (IARI), New Delhi during rainy and winter seasons of 2010-2011 and 2011-2012 to examine consumptive use of water (CW), water-use efficiency (WUE), nutrient uptake and balance, and energy-use efficiency (EUE) of nine diverse cropping systems based on three rainy season crops - pearl millet (Pennisetum glaucum (L.) R. Br.), cluster bean (Cyamopsis tetragonoloba L.), and green gram (Vigna radiata L. Wilczek) followed by three winter crops - wheat (Triticum aestivum L.), chickpea (Cicer arietinum L.), and mustard (Brassica juncea L.) in each of those three rainy season crop planted fields under no-till semi-arid rainfed conditions. Three residue treatments [i.e., no residue, crop residue, and Ipil-ipil {Leucaena leucocephala (Lam) twigs}] were examined for both rainy season and winter crops. Retention of crop residues significantly increased soil moisture, CW, and WUE in all cropping systems. Good growth of mustard, chickpea, and wheat after cluster bean, and a large amount of cluster bean green pods resulted in substantially higher CW and WUE of cluster bean-based systems compared to pearl millet- and green gram-based systems. Crop nutrient uptake increased substantially under crop residue and Leucaena twigs treatments compared to no-residue control plots due to enhanced crop growth and augmentation of nutrients. However, nutrient uptake and apparent nutrient balances varied greatly among cropping systems. Energy input requirement increased by approximately 10 times under crop residue and Leucaena twigs treatments. As a result, net energy balance and EUE were substantially higher for no-residue treatments. Leucaena twigs treatments had higher net energy balance and EUE than crop residue treatments, indicating the importance of leguminous residues in crop production. Results indicate the necessity of exercising optimal balance between retention of crop residues and energy inputs for the long-term soil health and sustainability of cropping systems.