添加玉米秸秆条件下土壤有机碳含量对温度变化的响应

通过室内培养试验,研究了不同温度(10、30、50℃)下添加玉米秸秆对土壤总有机碳、团聚体有机碳、水溶性有机碳及腐殖质碳含量的影响。结果表明,与未添加玉米秸秆(CK)相比,添加玉米秸秆后土壤中以上各种有机碳含量均明显增加,同时促进了土壤微团聚体向大团聚体的转化。随培养温度的升高,添加玉米秸秆后的土壤总有机碳含量、土壤中0.25~0.053和0.053 mm粒级团聚体有机碳含量以及土壤腐殖质组分(胡敏酸和富里酸)的有机碳含量下降,而2~0.25 mm粒级团聚体有机碳含量增加,说明添加玉米秸秆后温度升高不利于土壤总有机碳、较小粒级团聚体有机碳、水溶性有机碳及腐殖质碳的积累,同时也不利于土壤大团聚体的形成。

Response of Soil Organic Carbon Contents after Corn Stalk Application to Different Incubation Temperatures

The effects of maize straw at different temperatures (10 ℃, 30 ℃, 50 ℃) on the soil organic carbon, aggregates associated organic carbon, water-solube organic carbon and humic substances carbon were studied using laboratory experiment. The results showed that, compared with control treatment, application of corn straw resulted in significant increase all of the above indexes, and promoted the transformation of soil micro-aggregates to macro-aggregates. With the incubation temperature increasing, soil organic carbon, 0.25~0.053 mm and <0.053 mm fraction of aggregate organic carbon content and the compo-sition of humus (humic acid and fulvic acid) organic carbon decreased after corn straw application, but the 2~0.25 mm frac-tion of aggregate of organic carbon content increased. These results indicated that, the rising of temperature was not con-ducive to the accumulation of soil organic carbon, micro-aggregate organic carbon, water-solube organic carbon and humic substances carbon after corn straw application, but also not conducive to the formation of soil macro-aggregates.