Effects of biochars on soil carbon pools under aerobic rice cultivation

Abstract

A field experiment was conducted at ZAHRS, College of Agriculture, UAHS, Shivamogga, during summer 2018 to know the effect of biochars on soil carbon pools under aerobic rice cultivation. The experiment was planned with 16 treatments consisting of four levels of biochar at 2, 4, 6 and 8 t ha-1 and two levels of FYM at 5 and 10 t ha-1 which were applied alone, and in combinations. The recommended dose of fertilizer (RDF) was applied commonly to all the treatments. The treatments were imposed in RCBD design with three replications for each treatment. The aerobic rice (MAS 946-1) was taken up as a testing crop. The result revealed that application of 8 t ha-1 biochar, 10 t ha-1 FYM with RDF (100:50:50 kg ha-1) to soil significantly increased the soil carbon pools viz. potassium dichromate oxidizable carbon (PDOC), potassium permanganate oxidizable carbon (PPOC), and soil microbial biomass carbon (SMBC) contents in soil at harvest of aerobic rice due to combined application of biochar (8 t ha-1) and FYM (10 t ha-1) applied with RDF compared to biochar, FYM, and RDF alone. Cold water extractable carbon (CWEC), total organic carbon (TOC), and total carbon (TC) contents in soil increased with increase in biochar rate but statistically no significant.