Studies on Productivity, Soil Fertility and N-Use Efficiency in Rice-Wheat-Mungbean Systems Using Tillage Options, Straw Management and Nitrogen Levels

Abstract

Rice-wheat rotation is the principal agricultural production system in South Asian countries. This system occupies around 13.5 million ha in the Indo Gangetic plains of Bangladesh, India, Nepal and Pakistan and 10.5 million ha in China (Ladha et al., 2003). Rice-wheat systems cover 32% of the total rice area and 42% of the total wheat area and account for about one-third the total rice and wheat production (Timsina et al., 2002). These systems have remained the major source of the marketed surplus of food grains for feeding the growing population. Rice and wheat are the world’s two most important cereals crops, contributing 45% of the digestible energy and providing 30% of the total protein in the human diet as well as making sustainable contribution to feeding livestock (Evans, 1993).Rice and wheat are now grown in sequence on the same land in the same year over 26 million ha of South and East Asia to meet up the food demand of rapidly expanding human population (Timsina and Cornor,2001 ).South Asian countries, Bangladesh, India, Nepal and Pakistan with a geographical area of 401.72 million ha, hold nearly half of the world population of 3.1 billion. Of which, 59% depends for livelihoods on agriculture. Nearly half of the land area is under agricultural crop production. It is estimated that nearly 60% of the farming households live on less than 30% of global agricultural lands (Gupta et al., 2003d) and approximately 240 million people in South Asia consume rice and/or wheat produced in rice-wheat systems ((Benites, 2001…………………………………