Prospects of Sodic soil Amelioration for Increased crop Production in India

摘要

Sodic soils are characterized by occurrence of excess sodium to a level that can adversely affect soil structure and nutrients availability for plants. The plants, growing in sodic soil, generally exhibit accumulation of Na+ and inhibit uptake of other essential nutrients, especially Ca, N and P which exerts poor growth and yield. In India, about 6.9 mha area is subjected to salt stress of which about 1.37 mha is in Uttar Pradesh. Challenges of food security in India require conversion of vast unutilized land to cultivable land to support increased area under productive agriculture. Although the use of chemical amendments, like gypsum successfully improves chemical properties of these soil, but fails to restore nutritional and biological properties of reclaimed soils. As a cost-effective and environmentally acceptable strategy, sodic soil can also be reclaimed through organic bio-amelioration. The incorporation of organic amendments to sodic soil enhances microbial activity that transforms the organic materials into long chain aliphatic compounds capable of bind- ing and stabilizing soil aggregates. Bioamelioration method has great advantage over chemical amendments like (1) improvement of soil hydraulic conductivity, (2) greater plant nutrient availability in amended soil, (3) environmental services through soil carbon sequestration. It is concluded that bioamelioration approach for sodic land reclamation would not only improve the soil fertility, but also make able the reclaimed sodic soil for agriculture that can fulfil the food requirements of growing population.