Abstract:
This paper studies the effect of fertilizer type on methane (CH4) and nitrous oxide (N2O) emissions in rice field, growing Pathumthani 80 or Gorkor 31 rice varietie, CH4 and N2O emitted from four types of fertilizers are compared: organic cow manure fertilizer, organic pellet fertilizer, organic liquid fertilizer, and chemical fertilizers (Urea 46-0-0 and Ammonium Phosphate 16-20-0). In this research, five different stages of rice cultivations were sampled 1) before-planting stage (0 day), 2) initial stage (30 days), 3) vegetative stage (60 days), 4) panicle-formation stage (90 days), and 5) maturation stage (120 days). CH4 and N2O emission was measured by Gas chromatography (GC) and Fourier transform infrared spectroscopy (FTIR).The paddy field with chemical fertilizer shows the highest CH4 emission at 1.19 mg/m-2/day, in contrast to those with organic pellet fertilizer giving the lowest CH4 emission. The CH4 emission rates in descending ranks are the plot with cow manure, the plot with organic liquid fertilizer, control plot without fertilizer, and the plot with organic pellet fertilizer, at 1.13, 1.04, 0.99 and 0.44 mg/m-2/day, respectively. For the N2O emission averages throughout rice grown season, the plot with organic cow manure fertilizer are released most throughout the growing season 1.84 mg/m-2/day maximum, followed by the plot with chemical fertilizer, control plot without fertilizer, the plot with organic liquid fertilizer and the plot with organic pellet fertilizer. By the emissions were 0.67, 0.66, 0.65 and 0.54 mg/m-2/day, respectively. It can be concluded, that the paddy field with chemical fertilizer gives the highest CH4 emission quantity, and The paddy field with cow manure fertilizers showed highest amount of N2O in paddy. The quantities of rice harvested from each plot of experiment the plot with chemical fertilizer, organic liquid fertilizer, organic cow manure fertilizer, control plot and the plot with organic pellet fertilizer were 6,513, 5,650, 5,269, 2,173 and 2,096 Kg/ha, respectively. Note that,this study has recommendations on the use of organic pellet fertilizers and chemical fertilizer to increase yield and reduce CH4 and N2O emission in paddy fields