Can Plant Nutrient Dynamics and Indian Mustard Yield Be Influenced by Addition of Organic Amendments Under Saline Sodic Soils?

Arid and semi-arid regions are having huge potential for agricultural production but also have limitations of salinity and alkalinity. By mediating rhizospheric environment with the application of organic and inorganic nutrient sources, Indian mustard yield could be enhanced in these areas. For this, a field experiment was conducted to study the effect of organic (FarmYard Manure and vermicompost) and inorganic (urea) amendments with irrigation water of different sodium absorption ratios (SAR; 6, 10, 20 and 30). The experiment was laid out in a split-plot design (SPD) with 24 treatment combinations keeping different SAR in main plots and organic and inorganic nitrogen sources in sub plots. Experiment results revealed that increasing SAR levels reduced the availability of major plant nutrients, i.e. nitrogen, phosphorus and potassium. The soil organic carbon mineralization rate and Indian mustard seed yield were also deceased with increasing levels of SAR. Application of nitrogen through farm yard manure (FYM) and vermicompost decreased the electrical conductivity (EC), pH, and enhanced the cation exchange capacity (CEC) of soil solution. Application of 50% recommended dose of nitrogen (RDN) through urea and 75% through vermicompost produced maximum seed and stover yield of Indian mustard. Thus, supply of recommended dose of nitrogen as inorganic (50%) and organic (75%) sources improved the soil health and Indian mustard yield of arid lands with sodic irrigation water. The use of organic sources in place of sole application of N fertilizer may be a potential management option in sodic groundwater irrigated areas for enhancing mustard crop yield.