Utilising organic wastes and alternative sources of plant nutrients for sustainable agriculture in Nepal

Subsistence oriented traditional agricultural practices in Nepal largely follow conventional approaches for soil fertility management. Conventional methods for soil fertility management rely primarily on use of compost and farmyard manure (FYM) as the main sources of plant nutrients. Recently, a shift from subsistence to semi-commercial production systems required changes in soil fertility management practices, which involved indiscriminate use of inorganic fertilisers, a decreasing trend of FYM and compost availability, and increasing use of poultry manure for crop production. More recent trends of commercial farming include crop intensification, use of high yielding varieties and specialised farming e.g. commercial vegetable and cash crops production. These are nutrient hungry production systems and currently dependent solely on inorganic fertilisers. Excessive nutrients depletion by these intensive production systems imposes severe consequences for soil fertility management, including increasing, and degradation of chemical, biological and physical properties of soil leading to loss of overall soil fertility and the appearance of severe micronutrients deficiencies in a number of crops. A far reaching and sustainable approach includes building integrated soil fertility management together with the use of under-utilised sources of plant nutrients such as bio-fertiliser technologies and recycling of organic residues, and enhanced composting (such as vermi-composting). Manufacturing of fertiliser products (granules, pellets, briquettes) from plant, animal and human wastes, and optimising the use of these products as alternative fertilisers are needed. The economic and environmental benefits from these products can be harnessed for sustainable production of crops, without jeopardising soil fertility and the environment. Achieving this result should be considered a priority goal for sustainable agriculture. This paper describes the scope of the alternative sources of plant nutrient management and their production and scaling-up for a wider adaptation in Nepal.