Potassium in Soil-Plant System: A Wider Perspective

摘要

The major concern for agriculture continues to meet the food needs of a world population projected to exceed 7.5 billion by the year 2020. With India's population touching almost 120 crore, there is a compelling need to increase the present agricultural production (241.6 Mt in 2010-11) from the available cultivable area (141M ha). The efforts to increase the agricultural production through scientific management under the aegis of 'Green Revolution' were highly successful. However, there are indications that the highly productive technologies involving use of chemical fertilizers and high yielding varieties introduced over the past three decades may be reaching a point of diminishing returns (Flinn and De Datta 1984; Bouis 1993; Cassman et al. 1995).Thus, in this new millennium, constraints faced in the field of agricultural production are many and challenging. Important among them are: limitations in the scope of - increase in cultivable area, spread of HYV, adoption of better agronomic practices,and use of chemicals in plant protection measures, and shortcomings in soil and fertilizer management practices. Prospects for expanding low-cost irrigation, one of the driving forces behind yield increases, are also becoming increasingly limited (Rosegrant and Svendsen 1993; Rosegrant 1997; Carruthers et al. 1997), as are the prospects for converting marginal lands into productive arable land (Bockman et al. 1990; Crosson and Anderson 1992). Furthermore, new technologies such as cultivation of genetically engineered yield-increasing plants are not expected to be major factors in food production increases in developing countries during the next two decades (Peng et al. 1994; Hazell 1995). Consequently, keeping pace with population growth and increasing land scarcity will be more difficult than in the recent past. Efficient soil and fertilizer management that had its own share in the success of the Green Revolution now needs a continuous and careful monitoring for balanced and optimized fertilization.Potassium is one of the major nutrient elements which will require a greater attention in order to ensure enhanced crop production and mitigation of bi-otic and abiotic stress as well as improvement in produce quality.