PAM和草类根系对荒坡侵蚀劣地紫色土微团聚体的影响

发布时间：2018-01-29 11:56

  本文关键词： 微团聚体 PAM 根系特征 根长密度 根表面积密度　出处：《草业学报》2017年12期 　论文类型：期刊论文

【摘要】：为探讨PAM(聚丙烯酰胺)和草类根系对侵蚀劣地土壤的改良效果,试验以该环境的紫色土为研究对象,设置了空白对照(CK)以及单施PAM、单植草类、"狗牙根+PAM"、"三叶草+PAM"4个试验处理类别,6个月后测定了土壤微团聚体组成,分析了土壤微团聚体分布、结构及分形特征。结果表明,1)各试验处理的大粒径微团聚体含量增加,小粒径的则减少;2)各试验处理的MWSSA(平均重量比表面积)、分散系数和分散率均显著减小(各指标最小值分别为CK的0.30、0.15和0.60倍),MWD(平均重量直径)、团聚状况和团聚度均显著增大(各指标最大值分别为CK的1.17、1.49和1.28倍);3)各试验处理的微团聚体分形维数均减小;4)GY-PAM1(狗牙根+液施PAM,浓度:30 g/m~3)土壤的各项微团聚体结构指标均优于其他试验处理,表现出较好的抗侵蚀性;5)"草类+PAM"的根系指标均优于单植草类,平均根长密度(RLD)和d(直径)≤0.2 mm径级分别是影响该紫色土结构稳定性和抗侵蚀性的主要因子和关键径级。
[Abstract]:In order to study the effect of PAM and grass root system on soil improvement of eroded soil, the purple soil in this environment was used as the research object, the blank CK was set up and PAM was applied only. The composition of soil microaggregates was determined and the distribution of soil microaggregates was analyzed after 6 months in four experimental treatments of monophyllodes, "PAM" and "PAM". Structure and fractal characteristics. The results show that the content of large particle size microaggregate increased and the small particle size decreased in each experiment. 2) the MWSSAs (average weight specific surface area, dispersion coefficient and dispersion rate) of each treatment decreased significantly (the minimum values of each index were 0.300.15 and 0.60 times of CK, respectively). MWD (mean weight diameter), agglomeration status and agglomeration degree increased significantly (the maximum values of each index were 1.17 ~ 1.49 and 1.28 times of CK, respectively); 3) the fractal dimension of microaggregates decreased in each experiment. (4) the soil microaggregate structure indexes of GY-PAM1 (concentration of 30 g / m ~ (-3)) were better than those of other experimental treatments, and showed better corrosion resistance. 5) the root system index of "grass PAM" was better than that of single plant grass. The mean root length density (RLDD) and d (diameter) 鈮，

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