民勤绿洲区苜蓿地土壤有机碳组分分布特征

发布时间：2018-09-12 16:55

【摘要】：为了解西北民勤绿洲区紫花苜蓿种植后土壤有机碳组分的变化趋势及影响因素,以民勤绿洲区3a(A3)、14a(A14)和22a(A22)苜蓿种植地为研究对象,以棉花种植地(CK)为对照,通过野外调查取样以及室内测试分析,对土壤中的全部有机碳(TOC)、重组有机碳(HFOC)、轻组有机碳(LFOC)、颗粒有机碳(POC)和微生物量碳(MBC)的含量进行测定,分析变化趋势并对其规律进行研究。结果表明:相对于棉花种植地,22a苜蓿地土壤容重和电导率分别降低了13.9%和95.4%。3~22a苜蓿地较棉花种植地(CK)的TOC、LFOC、HFOC和MBC分别表现出175.0%,1 416.0%,47.8%和216.0%的增长幅度,变化差异较为显著。在垂直剖面上,棉花种植地(CK)显著低于苜蓿地LFOC、POC、MBC含量,并随土层加深而不断降低。逐步回归分析表明LFOC与TOC显著正相关(p0.05)。苜蓿种植年限、土层以及这两个变量的交互作用对POC/TOC产生显著影响(p0.01),对TOC、LFOC、HFOC、POC、MBC、LFOC/TOC、HFOC/TOC和MBC/TOC均产生极显著影响(p0.001)。苜蓿种植提高了土壤质量,降低了土壤容重和盐碱性,连续种植14a是苜蓿最为合理的种植年限,同时苜蓿种植有利于0—60cm垂直土层有机碳组分的累积,尤其对TOC、LFOC和MBC的增长效果极其显著。
[Abstract]:In order to understand the change trend and influencing factors of soil organic carbon composition of alfalfa after planting in Minqin oasis area of Northwest China, the 3a (A3) 14a (A14) and 22a (A22) alfalfa cultivation fields in Minqin Oasis area were used as research objects and (CK) as control. The contents of organic carbon (LFOC),) particulate organic carbon (POC) and microbial biomass carbon (MBC) in all organic carbon (TOC),) recombined organic carbon (HFOC),) light groups in soil were determined by field investigation and laboratory analysis. The results showed that the soil bulk density and electrical conductivity of alfalfa field were decreased by 13.9% and 95.40.3a, respectively, compared with that of cotton cultivation area (CK), the TOC,LFOC,HFOC and MBC of alfalfa field were 175.00.1416.0% and 216.0%, respectively, and the difference was significant. The results showed that the soil bulk density and electrical conductivity of alfalfa field decreased by 13.9% and 95.40.30.The results showed that the TOC,LFOC,HFOC and MBC of alfalfa field were 175.0% and 216.0%, respectively. In the vertical section, the (CK) content of cotton planting land was significantly lower than that of alfalfa land, and the content of LFOC,POC,MBC decreased with the deepening of soil layer. Stepwise regression analysis showed that there was a significant positive correlation between LFOC and TOC (p0.05). The years of alfalfa planting, soil layer and the interaction of these two variables had a significant effect on POC/TOC (p0.01), and on TOC,LFOC,HFOC,POC,MBC,LFOC/TOC,HFOC/TOC and MBC/TOC (p0.001). Alfalfa cultivation improved soil quality, decreased soil bulk density and salt alkalinity, and was the most reasonable planting period for alfalfa for 14 years. Alfalfa cultivation was beneficial to the accumulation of organic carbon in vertical soil layer of 0-60cm. Especially for TOC,LFOC and MBC growth effect is extremely remarkable.
【作者单位】：甘肃农业大学林学院;甘肃省农业工程技术研究院;
【基金】：国家自然科学基金项目(41561062,31560170,31560238) 甘肃省自然基金项目(1308RJZA256)
【分类号】：S153.62

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