Soil Management to Increase Rice Yield in Salt affected Coastal Soil - A Review

Abstract

India is facing one of the largest challenges of this century to continue to increase annual rice
production to about 125 Mt by 2020 to ensure food security with shrinking cropland and limited resources,
while maintaining or improving soil fertility, and protecting the environment. Rich experiences in integrated
and efficient utilization of different strategies of crop rotation, intercropping, and all possible nutrient
resources accumulated by Indian farmers in traditional farming systems have been gradually abandoned and
nutrient management shifted to over-reliance on synthetic fertilizers. In India, the coastal saline soils are
spread in an area of about 3.1 M ha. Out of 42.0 M ha of total area of rice, 55 percent of rice predominantly
cultivated in coastal areas. The soils of coastal region offer many unique problems like salinisation, water
logging and clay pan formation. Apart from that, the soils of this region are mostly coarse textured single
grain structure soil with low water and nutrient retention capacity, high pH and EC, low base saturation and
organic matter content. There is little doubt that current nutrient management practices are not sustainable
and more efficient management systems need to be developed to increase rice yield in coastal soil. In this
connection a review of soil management to increase rice yield in coastal soil conducted around the world
indicated that to sustain the rice productivity, chemical fertilizer alone is not enough to improve or maintain
soil fertility at high levels and it is essential to follow the combined application of inorganic fertilizers with
organic manures and integrated nutrient supply system plays a vital role in sustaining soil fertility under
sodic soil in coastal region on long term basis. On account of continuous world energy crisis with increasing
prices of chemical fertilizer the use of organic manures as renewable sources of plant nutrients is gaining
importance. In this endeavor proper blends of organic and inorganic fertilizer are of utmost important not
only for increasing yield and for soil health and the continuous use of organic and inorganic soil
amendments speed up the process of reclamation of sodic soil. In addition Nutrient availability from organic
sources offer more balanced nutrition to the plants, especially micronutrients which has caused better
tillering in plant growth, dry matter production and yield of rice. Apart from that, innovative and effective
extension and service-providing systems to assist farmers in adopting and applying new nutrient
management systems and technologies are also crucially important for coastal region to meet the grand
challenge of food security, nutrient-use efficiency and sustainable development.