Alternative sources of soil organic amendments for sustaining soil health and crop productivity in India - impacts, potential availability, constraints and future strategies

Among the several causes, critical low soil organic matter status is predominant for decline in soil health and consequent fall in crop productivity. Over the years, availability of traditional source of soil organic amendment, viz. cattle manure drastically declined due to various reasons (domestic uses as fuel and plastering of the kachha houses). The present study highlights that there are many alternative sources of soil organic amendments available in the country which have tremendous potential to improve soil organic matter status and crop productivity, and rejuvenate and enhance the dying total factor productivity of Indian soils. Data from various sources reveal that about 300 million tonnes of alternative sources of soil organic amendments are available in the country. This study highlights that the application of alternative sources of organic amendments directly or indirectly improves soil health by influencing many soil properties (physical and chemical) and enzyme activities (biological) that regulate nutrient dynamics in the soil. Consequent upon improvement in soil environment, the application of alternative sources of soil organic amendments alone or along with recommended dose of fertilizers registered significantly higher yield in different crops across different agro-climatic conditions of the country. Composting and vermicomposting are the best strategies to convert the biomass of available alternative sources of organic amendments to plant nutrient-rich products.