秸秆还田对滨海粘质盐土物理性状和棉花产量的影响

为了研究秸秆还田对滨海粘质盐土物理性状的改良效果,在黄河三角洲滨海粘质盐化潮土区进行田间试验,设置了秸秆用量为0、1.5、3.0、4.5 t/hm24个不同处理,探讨不同秸秆还田量对土壤容重、孔隙状况、饱和导水率、土壤盐分含量和分布以及棉花产量产生的影响。研究结果表明:在0~20 cm的秸秆耕翻层,随秸秆还田量的增加,土壤容重降低,土壤总孔隙度增加;与对照处理相比,3个秸秆处理的土壤通气孔隙比例分别增加2.70%、9.52%和12.16%(P0.05),土壤饱和导水率提高56.28%、100.93%和161.4%(P0.01),0~20 cm表层土壤含盐量分别下降了28.08%、50.75%和40.71%(P0.01)。秸秆粉碎还田会明显改善土壤通气状况和土壤水分入渗性能,有效抑制表层土壤盐分积累,对滨海粘质盐土改良具有重要作用,是盐碱土改良的重要途径。但是,要注意控制秸秆还田量,以3.0 t/hm2的秸秆还田量为宜。

Effects of Straw Turnover on Physical Properties of Coastal Saline Clay and Cotton Yield

In order to determine the improving effect of straw turnover on physical properties of coastal saline clay, a field experiment was carried out in the coastal saline clay region in Yellow River Delta, four straw application amounts were set up, which were 0, 1.5, 3.0 and 4.5 t/hm², the effects of straw turnover on soil bulk density, porosity, saturated hydraulic conductivity, soil salt content and cotton yield were analyzed. The results showed that the soil bulk density declined and the porosity increased with the increase of straw amount in 0-20 cm soil layer; the proportion of aeration porosity of the three straw turnover treatments increased by 2.70%, 9.52% and 12.16% compared with that of CK(P<0.05); the saturated hydraulic conductivity increased by 56.28%, 100.93% and 161.4% respectively (P<0.01); and the soil salt content in 0-20 cm soil layer decreased by 28.08%, 50.75% and 40.71% respectively (P<0.01). The soil porosity situation and the ability of infiltration were improved obviously after straw turnover, soil salt accumulation in surface layer was restrained effectively, straw turnover played an important role in the improvement of the coastal saline clay, and could be an important way to improve saline soil. The application amount of straw should be concerned, 3.0 t/hm² was the appropriate amount of straw turnover.