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选择湖南省3个国家级稻田肥力变化长期定位监测点的土壤,分别在10、20和30℃进行室内恒温培养试验,研究温度和施肥对土壤有机碳矿化的影响及其与不同碳形态含量的关系.结果表明:在培养前期(0~13 d)土壤CO2产生速率较快,后期逐渐下降,其速率变化符合对数函数;升温促进了土壤有机碳矿化,各施肥处理土壤中,以秸秆还田和化肥配施有机肥处理土壤有机碳的累积矿化量较多;各施肥土壤的Q10值为1.01~1.53,与总有机碳、易氧化有机碳、胡敏酸碳和富里酸碳呈显著正相关;在10和20℃下CO2矿化量与微生物生物量呈显著的线性相关关系,而30℃下则无显著相关关系;CO2矿化量与不同碳形态含量和胡敏酸碳/富里酸碳呈显著的线性正相关;在10℃下矿化率与不同碳形态含量呈显著的线性负相关,在20和30℃下,矿化率与不同碳形态含量无明显相关关系.因此可以通过施用秸秆和有机肥增加对土壤碳的固定,减缓大气CO2浓度的升高,减少温室气体排放.
Soil samples from 3 national long-term paddy fertility change monitoring sites in Hunan Province were selected and incubated at 10, 20 and 30 ℃ respectively. The effects of temperature and fertilization on soil organic carbon mineralization were investigated. The results showed that in the early stage of culture (0 ~ 13 d), the soil CO2 production rate was faster and the later stage decreased gradually, and its rate change was in accordance with the logarithm function; warming promoted the soil organic carbon mineralization, Soil organic carbon accumulated by straw returning and organic manure application was higher than that of organic fertilizer treatment. The Q10 values of all fertilizing soils were 1.01-1.53, which were positively correlated with total organic carbon, readily oxidizable organic carbon, humic acid carbon and fulvic acid There was a significant positive correlation between CO2 mineralization and microbial biomass at 10 and 20 ℃, but no significant correlation was found at 30 ℃. The relationship between CO2 mineralization and carbon content and humic acid carbon / Fulvic acid showed a significant linear positive correlation; at 10 ℃ mineralization rate and the content of different carbon forms was significantly negative linear correlation at 20 and 30 ℃, the mineralization rate and the content of different carbon forms no significant correlation. So can be applied by straw and there Fertilizer increases soil carbon fixation, slowing the increase of atmospheric CO2 concentration and reducing greenhouse gas emissions.