Enriched Charred Rice Husk to Improve the Nutrient Management in Rainfed Groundnut

Abstract

Background: The uncertainty of groundnut productivity in the rainfed areas could be minimized by in situ conserving the soil moisture received through precipitation during the cropping period and improving the nutrient status. Methods: A field experiment was conducted at the Department of Agronomy, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, Tamil Nadu during 2014-2015 rabi season to find out the effect of charred rice husk and other organic materials enriched with or without fertilizer nutrient on the moisture retention and nutrient supply during the deficit period of crop growth. The treatment consists of charred rice husk, biochar, lignite and farm yard manure alone and enriched with the recommended dose of nitrogen (10 kg ha-1) and phosphorus (10 kg ha-1) fertilizer and compared with the absolute control and recommended dose of fertilizer (10:10:45 kg NPK ha-1). Result: The structural morphology of organic materials was studied using Scanning Electron Microscope (SEM) showed that the particles of charred rice husk were uneven and the diameter varied from 3-4 pm with clod and block appearance, the particles of biochar were irregular in shape, uneven sized and diameter varied from 2-3 pm with block appearance and the lignite particles found spherical and aggregated. The chemical composition of organic manure with nutrient examined under SEM-EDAX revealed that the charred rice husk contains 64.31% carbon, 28.42% oxygen and 5.96% silica. Results of the study revealed that, application of enriched FYM at 5 t ha-1 recorded significantly higher pod yield (2190 kg ha-1). The enriched biochar and charred rice husk produced comparable pod yield of 2010 kg ha-1 and 1983 kg ha-1, respectively.