Productivity, nutrient uptake and post-harvest soil fertility in lowland rice as influenced by composts made from locally available plant biomass

摘要

A field experiment was conducted during the kharif (rainy) seasons of 2005-2006 to study the effect of eight composts prepared from four different types of plant biomass (rice straw (Oryza sativa), Eupatorium adhenophorum, Lantana camara and grass/weed mixtures) following two composting procedures: (i) Microbial Enriched Compost (MEC) [biomass + cow dung + compost culture (formulations of cellulose decomposers, P-solubilizing microbes and free-living N-fixers], and (ii) Microbial and Nutrient Fortified Compost (MNFC) [MEC + rock phosphate at 2.5% (w/w) + neem cake 1%] on productivity of lowland rice. Recommended NPK (80:60:40 kg ha-1) and farmyard manure (FYM) at 10t ha-1 (similar to compost dose) treatment were also kept for comparison. In general, the performance of rice under MNFC composts was superior to MEC composts. The results revealed that the grain yield of rice with rice straw MNFC compost and Eupatorium MNFC compost were 5% and 3% higher than recommended NPK, respectively. The nutrient uptake and post-harvest soil fertility status were also significantly higher under these treatments compared to recommend NPK. In the present study, although the increments in grain yield of rice with various composts were not much during two years experimentation, substantial improvement in soil fertility in terms of available NPK was observed.