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采用PAM、β-环糊精、沃特保水剂、腐殖酸等4种土壤结构改良剂,通过室内土柱培养,以研究其对风沙土有效的改良效果,并探讨其作用机理和合理的施用浓度。结果表明,4种改良剂均可促进>0.25 mm水稳性团聚体的形成,在低浓度(0.05%~0.1%)下其趋势为:沃特保水剂>β-环糊精>PAM>腐殖酸,在高浓度(0.2%~0.4%)下趋势为:PAM>β-环糊精>沃特保水剂>腐殖酸。4种改良剂在浓度为0.05%~0.4%时,均可有效地降低风沙土团聚体的分形维数,改善风沙土结构,尤其沃特保水剂改良效果最明显。在低浓度下,4种改良剂均可有效地降低土壤容重。回归分析和方差分析表明,沃特保水剂主要作用于5~1 mm粒径的团聚体,其适宜浓度为0.05%左右。
Four kinds of soil structure improvers such as PAM, β-cyclodextrin, water retaining agent and humic acid were used to study the effective improvement effect on sandy soil by means of soil column cultivation. The mechanism of action and reasonable Application concentration. The results showed that the four modifiers could promote the formation of> 0.25 mm water-stable aggregates. The trend of water-soluble aggregates at low concentration (0.05% -0.1%) was: water retaining agent> β-cyclodextrin> PAM> Formic acid, the trend of high concentration (0.2% ~ 0.4%) is: PAM> β-cyclodextrin> Water retaining agent> humic acid. When the concentration of the four modifiers is 0.05% ~ 0.4%, the fractal dimension of aeolian sand aggregates can be effectively reduced and the aeolian sand soil structure can be improved. In particular, water repellent has the most obvious improvement effect. At low concentration, four kinds of modifiers can effectively reduce soil bulk density. Regression analysis and ANOVA showed that water retaining agent mainly acts on agglomerates of 5-1 mm in diameter, and its suitable concentration is about 0.05%.