Effects of Rice Husk Charcoal under Chemical and Organic-chemical Paddy Filed on CH4 Emission, Growth and Yield of KDML 105 Rice

Abstract

Paddy soils in the northeast of Thailand are the low soil fertility. The application of organic materials to the soil lead to increase methane gas (CH4) emission. Charcoal is the organic material as high carbon content and stability to decomposition and result to decrease Methanogenic bacteria activity. The experiments were conducted on farmer paddy fields. Two paddy fields were selected to use for this experiment i.e. chemical and organic-chemical paddy fields. The experimental design was RCBD with 4 treatments and 4 replications including; 1) no amendment, 2) rice husk charcoal, 3) farmer practice and 4) farmer practice + rice husk charcoal (panicle initiation stage: PI). The results of this research found that at initial growth of rice were not different between rice husk charcoal amendment and farmer practices under both chemical and organic-chemical paddy fields. These results indicated that initial growth stage of rice does not need addition chemical fertilizer. However, rice husk charcoal amendment at PI stage was improved rice productivity higher than farmer practices under chemical paddy field condition. Rice husk charcoal amendment was highest rice grain as yield 150 kg/rai under chemical paddy field, while, rice husk charcoal amendment and farmer practice were not significant difference in grain yield (424 and 425 kg/rai, respectively) organic-chemical paddy field. Rice husk amendment under chemical paddy field was highest CH4 emission during weeks 2 and 3 after transplanting. While, farmer practice under organic-chemical paddy field was highest CH4 emission. However, under low organic matter paddy field will induce to high CH4 emission when increase organic matter (rice husk charcoal) and decrease CH4 emission under high organic matter paddy field.