Long Term Effects of Integrated Plant Nutrition System on Rice Yield, Nitrogen Dynamics and Biochemical Properties in Soil of Rice-rice Cropping System

Long term fertilization from manure and fertilizer influences crop yield as well as soil nutrient cycling. Therefore, a field experiment was conducted from 2010 to 2014 in order to observe the long term effects of integrated application of manure and fertilizers on rice yield, soil nitrogen dynamics and soil biochemical properties. The field experiment was carried out in a rice-fallow-rice cropping pattern under wetland condition with four fertilizer management practices: NPKS fertilizer as soil test based (STB), Cow dung (CD) @ 3 t ha-1 + NPKS as integrated plant nutrition system (IPNS) [CD+IPNS], Poultry manure (PM) @ 2 t ha-1 + NPKS as IPNS [PM+IPNS] and N control. The rice grain yield, soil N dynamics and the biochemical properties assessed in our study significantly varied with the organic sources used in IPNS system. The annual grain yield of double cropped rice with PM+IPNS was similar to the STB treatment over the five cropping years while CD+IPNS responded from the third year. After five years of rice cropping PM+IPNS showed better impact on soil nitrogen dynamics and biochemical properties compared to STB fertilizer management. Considering the soil health, our study suggests that PM+IPNS could be a good practice for sustainable rice production in long run reducing the use of chemical fertilizer.