改良剂对复垦土壤水稳性团聚体及POC和MOC的影响

为探究改良剂对煤矿复垦土壤有机碳的影响,以山西省襄垣县煤矿复垦区复恳7年的土壤为研究对象,采用田间微区的方法研究了泥炭和腐殖酸对复垦土壤及各粒级水稳性团聚体颗粒态有机碳(POC)和矿物结合态有机碳(MOC)的影响。结果表明:施用泥炭和腐殖酸均能增加复垦土壤水稳性大团聚体(>0.25 mm)含量,但6个月后,水稳性大团聚体会减少,而水稳性微团聚体(<0.25 mm)会增加,>2 mm和<0.25 mm粒级的团聚体变化较大,2种改良剂相比,腐殖酸各处理土壤大团聚体及微团聚体的变化比泥炭大。泥炭和腐殖酸均能增加复垦土壤总POC、MOC含量及各粒级水稳性团聚体中的POC、MOC含量,施用比例相同时,施用腐殖酸的土壤POC、MOC增量更大,施用泥炭6个月和1年后土壤POC含量变化分别为2.14~8.89,1.53~5.00 g/kg,施用腐殖酸6个月和1年后土壤POC含量变化分别为8.07~20.12,5.63~19.36 g/kg,施用泥炭6个月和1年后土壤MOC含量变化分别为4.84~10.51,5.41~8.08 g/kg,施用腐殖酸6个月和1年后土壤MOC含量变化分别为9.10~35.34,5.91~30.00 g/kg。但6个月后,泥炭和腐殖酸各处理土壤POC和MOC含量会减少。施用泥炭和腐殖酸会降低土壤有机碳的稳定性,不利于有机碳的储存。

Effects of Amendments on Water-stable Aggregates and POC and MOC in Reclaimed Soil

The objective of this study was to explore the effect of amendments on soil organic carbon in reclaimed soil. A series of micro field experiments were set to study the effect of peat and humic acid on particulate organic carbon (POC) and mineral-bound organic carbon (MOC) of soil and water-stable aggregates in the soil, which has been reclaimed for seven years in Xiangyuan, Shanxi province. The results showed that peat and humic acid increased the content of water-stable macroaggregates (>0.25 mm) in reclaimed soil. After 6 months, the content of water-stable macroaggregates was decreased and the content of water-stable microaggregates (<0.25 mm) was increased, the change of aggregates with >2 mm and <0.25 mm aggregates were obvious. Compared with the two amendments, the changes of soil macroaggregate and microaggregate in humic acid treatment were greater than those in peat. Peat and humic acid increased the contents of POC and MOC of soil and all level water-stable aggregates in reclaimed soil. When the application ratio was the same, the increases of POC and MOC in soil with humic acid were greater. After applying peat for 6 months and 1 year, the POC contents were 2.14~8.89 g/kg and 1.53~5.00 g/kg, and after applying humic acid for 6 months and 1 year, the POC contents were 8.07~20.12 g/kg and 5.63~19.36 g/kg. After applying peat for 6 months and 1 year, the MOC contents were 4.84~10.51 g/kg and 5.41~8.08 g/kg, and after applying humic acid for 6 months and 1 year, the MOC contents were 9.10~35.34 g/kg and 5.91~30.00 g/kg. However, after 6 months, the contents of POC and MOC were decreased. Peat and humic acid reduced the stability of soil organic carbon, it''s not beneficial for the storage of organic carbon.