Yagya Gajadhar Khadka and Pramod Sharma
Soil Science Division, NARC

Abstract

Agriculture is the mainstay of the national economy which accounts for about 34.1 % of the GDP and 65.5% of the employment. Currently Nepal needs sustainable agriculture production for the maintaining soil and crop productivity for the long run. Soil organic matter has different functions in plant growth and developments. The liberation of nutrients from the organic materials occurs during the microbial decomposition dynamics of soil organic matter. Mineral fertilizers are expensive commodities and small and marginal farmers are not able to use these fertilizers in adequate amount. On the other hand, soil quality is deteriorating due to imbalance and inadequate use of mineral fertilizers and lacking of soil organic matters. To maintain soil fertility using organic and biological fertilizers in combination with the mineral fertilizers has its own importance under integrated plant nutrient system (IPNS), which aims at maintaining soil fertility for Sustainable and environmentally sound agricultural production. There is no universal IPNS application to all circumstances. The suitable combination of mineral fertilizers, organic manures, crop residues, and bio fertilizer varies according to the cropping systems, land use systems, ecological, social and economic condition. A number of studied were carried out in the country to identify the best combination of various plant nutrients sources to sustain soil fertility. The results of some of these studies are briefly disused in this review paper.