Effect of Tillage and Weed Control Methods on Weeds and Yield of Rice-Wheat and Soybean-Wheat Cropping Systems

摘要

Wheat is the major winter season cereal crop grown in an area of about 27 million hectares in India under diverse agro-ecological conditions. It is rotated with rice (about 10.5 m ha) in the Indo-Gangetic Plains (IGP) and with soybean (about 2.0 m ha)mostly in Madhya Pradesh. However, rice-wheat cropping system has become more fragile and system productivity is showing the sign of fatigue (Hobbs and Morris, 1996). In recent years, major emphasis in this system has been on crop diversification with greater inclusion of legumes and use of resource conservation technologies to alleviate declining factor productivity, input use efficiency and increasing cost of cultivation for realizing sustainable use of natural resources. Zero tillage and bed planting have been widely adopted by the farmers in more than one million hectares area of Indo-Gangetic Plains. Altering tillage practice changes weed population dynamics, including weed seed distribution and abundance in the soil seed bank and affects the efficacy of control practices. Different tillage implements move the soil in different ways and, therefore, have substantially different effect on weed seed distribution in the soil profile. Keeping these points in view, the present investigation was conducted.