Water management and rice husk biochar application to solve acid sulfate soil problems to promote rice yield and reduce greenhouse gas emission

The use of biochar for soil fertility improvement is gaining popularity due to its potential to improve soil quality and increase crop yield in swampland. Water management plays a key role in controlling various dynamic processes such as acidity production. The water management system in acid sulfate soil should have a proper leaching and flushing capacity of the oxidation product. When these soils are used for rice, we found that the most important constraints were (1) Acidity (which includes the combined effects of pH, Al toxicity, and P deficiency) and (2) Fe stress (which is due to the combined effects of Fe toxicity and deficiencies of other divalent cations such as calcium/Ca). The experiment was carried out to investigate the effects of water management and rice husk biochar and compost applied in combination (0,1% of each w/w, thus 0,1% compost + 1% rice husk biochar) on growth, the yield of rice and methane emission on acid sulfate soil. The Provision of 50% compost + 50% Biochar rice husk with washing water management every two weeks (P2) in acid sulfate soil could reduce methane emissions by up to 53.16% with the highest dried unhusked rice yield of 3.86 t/ha.