Research Projects

There is lack of systematic study on utilization of built-up phosphorus (P) in different soils of India for crop production. In this context, developing the cost-effective ways to solubilize native accumulated P in different soil chemical environments is of utmost importance and has enormous practical relevance for reducing dependency on imported chemical fertilizers. Synergistic interaction between silicate and phosphate can be exploited in this aspect, as silica (Si) can compete with P for the adsorption sites in soil and various Si rich crop residues should be evaluated for their effectiveness in enhancing fixed inorganic P in soil. Phosphate solubilizing bacteria (PSB) are also known to solubilize fixed P in soil. These will be cheaper options of P as well as residue management. In case of potassium (K), due to high cost of fertilizer, farmers either skip or apply K at a rate far less than its recommended dose, leading to soil K mining under intensive cropping. To check the soil health deterioration due to soil K mining and to reduce the huge expenditure on import of K fertilizers by Indian government, viable indigenous K sources should be evaluated. Therefore, present investigation is proposed to be undertaken to (i) assess fractions of P and K in major soil orders of India, (ii) study the effect of Si and PSB on the available P in different soil orders and its uptake by crops, (iii) assess the efficacy of nonconventional sources of K in different soil orders in maintaining available K in soil and its uptake by crops, and (iv) study the effect of chemical and biological interventions on soil health. For this purpose, soil samples will be collected from major soil orders of India e.g. Inceptisol, Entisol, Alfisol, Vertisol and Ultisol with varying soil properties. Important relevant physical and chemical properties of soils will be determined following standard procedures. Greenhouse pot experiment will be conducted to assess the effect of Si rich crop residues and PSB on solubilization of fixed P in soil and P uptake by crops using the collected soil samples. Another greenhouse pot experiment will be conducted to evaluate the K supplying capacity of nonconventional sources to crops. Further, field experiments will be conducted at Indian Agricultural Research Institute, New Delhi to validate the results of greenhouse pot experiments. Changes in different P and K fractions and soil properties will be assessed. Successful completion of the project will generate information on feasibility of using crop residues and K bearing minerals having a good reserve in India to support P and K nutrition of crops. This will reduce dependency on imported chemical fertilizers vis a vis high grade rock phosphate and ultimately decreasing the burden on Indian economy. Further, this will help to increase the interest of Indian farmers not to burn crop residues in the field as it will reduce the fertilization rate of P and K through chemical fertilizers.