Conservation Agriculture for Rice-Wheat Cropping System

摘要

Rice-wheat is a dominant cropping system grown in more than 22 Mha area in India, Pakistan, Bangladesh, Nepal and China. Rice and wheat are the staple food crops of Asia and contribute more than 80% of the total cereal production. In India rice-wheatbelt grapples with declining soil health and ground water-table and thus the conservation agriculture could hold the key to increase the productivity. Several studies have indicated that the rice-wheat cropping system is fundamental to employment, incomegeneration and livelihood for hundreds of millions of rural and urban poor of South-East Asia (SEA). Throughout SEA puddling is used to prepare soil for lowland rice. In-terms of the degree of alteration of soil structure, puddling is rather extreme form of tillage, because it results in aggregate breakdown and the destruction of macro pores (Voase-Ringrose et al. 2000). The long turnaround time is needed to prepare puddled Vertisols for subsequent wheat crop after rice. The delayed planting of wheat crop beyond 15th November declines wheat yields considerably (Tomar and Verma 1985). The potential benefits of key conservation technologies developed at JNKW and other SAUs to enhance crop productivity and resource use efficiency of rice-wheat cropping system in Vertisols of Central India are discussed here.