摘要
矿区土地复垦中,由于机械碾压导致复垦土壤呈现高压实状态,复垦土壤的有机质则因机械扰动而矿化。探究复垦土壤团聚体与有机质恢复机理,可为深入理解露天煤矿高压实复垦土壤质量演替规律提供依据。以平朔露天煤矿典型植被恢复模式——刺槐纯林不同复垦年限(0、3、12、14、17、25、28、32 a)土壤及周边未扰动土壤(CK)为研究对象,采集0~20 cm表层土壤样品,分析土壤水稳性团聚体(>2000μm、>250~2000μm、53~250μm、<53μm)及团聚体碳(C)、氮(N)以及^(13)C和^(15)N同位素特征。结果表明:1)土地复垦中机械碾压破坏了土壤水稳性团聚体结构与稳定性,但随着复垦时间增加,32 a样地>250~2000μm团聚体的比例较0 a提高737.02%,而53~250μm团聚体比例则降低19.25%;团聚体稳定性随着复垦时间而增加,表现为32 a样地土壤团聚体平均重量直径(Mean Weight Diameter,MWD)较0 a提高133%。2)各粒径团聚体C、N及C/N均随着复垦时间增加而增加,>2000和>250~2000μm团聚体C和N在土壤总C和N中占主导地位。>2000和>250~2000μm团聚体C/N整体上高于53~250μm团聚体。3)各样地土壤δ^(13)C变化范围为−15.14‰~−26.40‰;δ^(15)N的变化范围为1.13‰~10.87‰。>2000、>250~2000和<53μm团聚体的δ^(13)C值及>2000μm团聚体的δ^(15)N值随复垦年限增加呈现降低趋势。与>2000μm和>250~2000μm团聚体相比,53~250和<53μm团聚体中13C显著富集(P<0.05),这表明复垦土壤熟化过程中,土壤C从大粒径团聚体向小粒径周转。4)>2000与>250~2000μm团聚体中,新C占土壤总C的比例为>80%,且各样地间差异不显著(P>0.05),而在<53μm团聚体中,新C的比例在复垦14~17 a间显著增加,此后则变化不显著。上述结果表明,土地复垦中机械碾压增加了小粒径团聚体的比例,降低了团聚体稳定性,而随着复垦时间增加,植被恢复促进了土壤团聚体结构、稳定性及C、N的恢复。
Reclaimed Mine Soil(RMS)is the type of high compacted and nutrient exhausted soil,due to the mining and reclamation operations.The soil aggregate associated carbon(C),nitrogen(N),and isotope can be a platform to understand the pedogenic process of reclaimed mine soil.This study aims to monitor the soil aggregate recovery and Soil Organic Matter(SOM)formation.Different sorts of age chronosequence soil(0,3,12,14,17,25,28,and 32 a)were collected from the Robinia pseudoacacia L.forests in the Pingshuo opencast coal mine in China.Moreover,the soil was selected from adjacent and undisturbed Populus simonii forest as a reference(CK)as well.The wet-sieving method was used to separate the fractions of soil aggregate,and the aggregate-associated C,N,^(13)C,and ^(15)N isotopes.The results showed that:1)The proportion of>250-2000μm aggregate in the 32 a soil was 737.02%higher than that in the 0a soil,whereas,the proportion of 53-250μm in the 32 a soil was 19.25%lower than that in the 0a soil,indicating that the reclamation operations destroyed the structure and stability of water-stable aggregate.Moreover,the mean weight diameter of soil aggregate in the 32 a soil was 133%higher than that the in 0a soil,indicating the excellent recovery of the structure and stability with the ages.2)Soil aggregate associated C and N increased with the reclamation time.The>2000μm and>250-2000μm associated C and N were dominated in the total C and N.In addition,the aggregate-associated C,N,and C/N ratio increased with the time.Specifically,the large-size aggregate(>250μm)associated C/N was significantly higher than that of the microaggregate(P<0.05).3)Theδ^(13)C values were differed from-15.14‰--26.40‰,while theδ^(15)N values were ranged from 1.13‰-10.87‰.More importantly,theδ^(13)C values decreased with the time in the soil aggregate>2000μm,>250-2000μm,and lower than 53μm,theδ^(15)N values decreased in the>2000μm as well.The ^(13)C isotopes were significantly enriched in the soil aggregate 53-250μm and lower than 53μm f
作者
原野
高嫄
赵艺芳
任迎香
Yuan Ye;Gao Yuan;Zhao Yifang;Ren Yingxiang(Center of Land Reclamation in Mining Area,Shanxi University of Finance and Economics,Taiyuan 030006,China;School of Public Administration,Shanxi University of Finance and Economics,Taiyuan 030006,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2022年第11期72-80,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41907408)
山西省高等学校科技创新项目(2019L0496)。
关键词
复垦
土壤
有机碳
团聚体
碳同位素
reclamation
soils
soil organic carbon
aggregates
carbon isotope
