Abstract:Aerobic incubation experiment was conducted with Eum-Orthic Anthrosols(Cinnamon soils)of sub-humid area to study the effects of temperature and water condition on soil N mineralization of 0—90 cm soil layer which was divided into three layers(each 30 cm thick).Soil samples were incubated at different temperature of 8.0,16.0,24.0,32.0,40.0℃ in tubers,and water contents were adjusted to 11.0%,15.0%,19.0%,23.0%,27.0%(w/w),sampling 7,14,21,35,49,63, 84 days after incubation,respectively.The results showed that N mineralization accumulation quantity of all soil layers increased with the increase of temperature and water content,in the order of 0—30 cm>30—60 cm>60—90 cm.Mineralizable N of the 0—30 cm soil layer was the major part,which accounted for 67.9% of total amount in 0—90 cm soil layer.Every soil layer had different mineralization process: mineralization process of 0—30 cm soil layer could be described with linear equation and 30—60 cm and 60—90 cm soil layers with logarithm equation during incubation.Statistical analysis significant correlation was obtained between the soil N mineralization rate(k) and water content(w),which correlation coefficient was above 0.93.It was found that soil N mineralization rate of 0—30 cm soil layer was most sensitive to temperature,30—60 cm was less,and 60—90 cm was least.As a whole,under the condition of higher incubation temperature,the N mineralization rate would be shower with the increase of temperature and soil layer depth. Temperature and water content of soil had interactive effects on the quantity and rate of N mineralization.To 0—30 cm soil layer,the positive effect of moisture on N mineralization was more evident than temperature under the higher incubation temperature,while to 30—60 cm and 60—90 cm,the effect of temperature was more evident.