Assessing the impact of zero tilled wheat growing in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) cropping systems: the case of central Uttar Pradesh in the Indo-Gangetic Plain.

摘要

Rice-wheat is the most commonly employed cropping system on around 14 million hectares of land extending across the Indo-Gangetic Plain (IGP). The IGP region covers the South Asian countries of Pakistan (2.2 million ha), India (10.5 million ha), Nepal (0.5 million ha) and Bangladesh (0.8 million ha). The major challenge facing the IGP's rice-wheat cropping system is to sustain long- term productivity. This system has a pivotal role in the food security and livelihoods of millions of farmers and workers of populous countries such as India, particularly in central Uttar Pradesh. The system's productivity and economic gains have been consistently decreasing, mainly because of the delayed sowing of wheat after the rice harvest and the fatigued soil condition. The region's farmers lose valuable time for pre-sowing irrigation and field preparation due to the gap of two to three weeks between the harvesting of rice and the planting of wheat. If wheat sowing is delayed beyond the optimal time (by late November), yields plummet at the rate of 30 kg per ha per day. The adoption of resource conservation technologies, such as zero tilled wheat sowing, is considered essential to maintain the productivity of the rice-wheat cropping system. Economic analysis of data for two years from six on- farm demonstrations shows that the zero tillage method of wheat cultivation is the most economical and attractive option for the farming community of central Uttar Pradesh. A high grain yield and reduced cost of cultivation per hectare, reduction in the density of weeds, especially Phalaris minor, and greater water saving were noted in zero tilled wheat sowings compared with conventional practices. As a result of field demonstrations and farmer training programmes, the introduction of zero till drill wheat sowing has expanded rapidly and has made significant contributions to the tillage revolution in the study area.