Effects of nitrogen fertilizer,soil moisture and temperature on methane oxidation in paddy soil were investigated under laboratory conditions. Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidati...Effects of nitrogen fertilizer,soil moisture and temperature on methane oxidation in paddy soil were investigated under laboratory conditions. Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism cell.Not only NH but also NO greatly affected methane oxidation.Urea did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed afterwards.Methane was oxidized in the treated soil with an optimum moisture of 280 g kg-1, and air-drying inhibited methane oxidation entirely.The optimum temperature of methane oxidation was about 30℃in paddy soil,while no methane oxidation was observed at 5℃or 50℃展开更多
Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of fir...Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of first-order-kinetics. According to the equation the change of soil ability to oxidize CH4 could be estimated by the equstion The results showed that the soil ability to oxidize CH4 varied, depending on the initial CH4 concentration.High initial CH4 concentration stimulated soil ability to consume CH4, while low concentration depressed the ability. This characteristic of paddy soil seemed to be of considerable significance to self-adjusting CH4 emission from flooded rice fields if there exist oxic microsites in the soil.展开更多
文摘Effects of nitrogen fertilizer,soil moisture and temperature on methane oxidation in paddy soil were investigated under laboratory conditions. Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism cell.Not only NH but also NO greatly affected methane oxidation.Urea did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed afterwards.Methane was oxidized in the treated soil with an optimum moisture of 280 g kg-1, and air-drying inhibited methane oxidation entirely.The optimum temperature of methane oxidation was about 30℃in paddy soil,while no methane oxidation was observed at 5℃or 50℃
文摘Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of first-order-kinetics. According to the equation the change of soil ability to oxidize CH4 could be estimated by the equstion The results showed that the soil ability to oxidize CH4 varied, depending on the initial CH4 concentration.High initial CH4 concentration stimulated soil ability to consume CH4, while low concentration depressed the ability. This characteristic of paddy soil seemed to be of considerable significance to self-adjusting CH4 emission from flooded rice fields if there exist oxic microsites in the soil.
