南方红壤丘岗区稻田土壤有机酸含量与甲烷排放率

分别采用分光光度和微机控制气相色谱法同时测定稻田土壤有机酸含量和甲烷排放率，以了解二者之间的关系，结果表明，在不同施肥实验小区，土壤有机酸含量随变化趋势一致，而甲烷放率随时间变化趋势则不尽一致，各小区土壤有机酸含量与甲烷排放率的相关性为全有机肥小区〉常规肥小区〉全化肥小区〉沼渣肥小区。在不同灌水实验小区，土壤有机酸含量与时间变化呈一致趋势，甲烷排放率随时间变化，除定常湿润小区外，也呈一致性趋势。各

Relationship between Organic Acid Content in Paddy Soil and Release of Methane from It in the Red Earth Hilly Areas in South China

Organic acid content(OAC) in paddy soil and release of methane(ROM) from it in the red earth hilly areas in South China were determined with spectrophotometry and microcomputer controlled gas chromatography, respectively. Four fertilization plots were found to have a consistent temporal trend of variation in OAC but not in ROM,and to have a correlativity between OAC and ROM as follows:the plot applied fully with organic manure (r=0.981 )>the plot fertilized in a normal way (r=0.855) >the plot applied fully with chemical fertilizers (r= 0. 353) > the plot applied with a biogas residue (r=0.0213). Four water management plots were found to have a consistent temporal trend of variation in both OAC and ROM, except for the plot of constant moisture, and to have a correlativity between OAC and ROM as follows:10 cm deep water covered plot(r = 0.993)> frequently drained plot (r = 0.910)>3cm deep normal water covered plot(r=0.714)> constant moisture plot (r= 0. 00526). OAC has the same vertical distribution in soil depth as that of ROM.