My journey in changing facets of agronomic research during three decades of green revolution in India

The changing facets of agronomic research in India as observed and followed by me during the past three decades, are reviewed in this paper. Green Revolution ushered in a new paradigm of agronomic management of crops in India. Fertilizer responsiveness of dwarf wheat generated heavy demand of fertilizers and gave major boost to the Indian fertilizer industry. Thus, due to the increased availability of fertilizers in the market, sugarcane farmers also started using heavy doses of N fertilizer to improve the cane yield, but at the cost of sugar content. Therefore, determination of optimum dose of N became important. In the first decade of my research career, I worked in this direction to work out the optimum dose and time of N application in sugarcane. Later on, with the introduction of fertilizer-responsive short-duration varieties in many crops like pulses and oilseeds, multiple cropping emerged as an important concept for intensification of agriculture. Consequently, I reoriented my research activities to develop companion cropping system with sugarcane and worked out fertilizer requirement of different crop combinations. Within two decades of Green Revolution, due to expansion of irrigation facility, rice-wheat crop rotation became predominant production system in the Indo-Gangetic plains, with gradual decrease in the area under pulse cultivation. Efforts were made to introduce pulses as companion crops of sugarcane for sustaining soil fertility and providing extra income to cane growers. Within a short span of time rice-wheat system, due to heavy de¬mand of nutrients developed soil fatigue and witnessed decline in factor productivity. My research interest again changed during 1980s towards conservation of soil-organic carbon, by utilizing the organic farm waste material and crop residues. Various options of green-manuring were also tried in rice-wheat and sugarcane-based cropping systems to achieve this objective and to increase the fertilizer-use efficiency. From high-input agronomy, my research interest thus, finally changed to conservation agronomy. Conservation of soil moisture through trash mulching, in-situ decomposition of trash using bio-agents and bio-manuring to improve the soil fertility as well as nutrient-use efficiency has now become my prime concern. In sugarcane, the improvement in productivity of ratoon crop remained a major research activity throughout my career.