摘要
为了研究不同类型的改良材料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土区进行田间试验,设置了泥沙用量为20、40 t/hm2,3种硅藻泥用量为1.5、3.0、4.5 t/hm2和对照试验,探讨不同改良材料与用量对土壤容重、孔隙状况、饱和导水率、土壤水盐分布以及对棉花生长和产量的影响.研究结果表明:在0~20 cm表层土壤中,不同处理的土壤容重和总孔隙度无显著差异;与对照相比,3个硅藻泥处理的大孔隙数量比分别降低0.51%、2.53%和4.75%,土壤饱和导水率降低1.18%、15.88%、22.65%,土壤含盐量降低62.76%、72.01%和75.76%(P<0.05),棉花产量降低2.8%、5.0%、11.1%;2个泥沙处理的大孔隙数量比分别增加了17.75%和37.09%,土壤饱和导水率增加17.94%、60.29%(P<0.01),土壤含盐量降低23.17%、25.08%(P<0.05),棉花产量增加11.1%、16.7%.引黄泥沙有效改善土壤质地和孔隙状况,增加土壤饱和导水率,适宜改良粘质盐土的物理性状.硅藻泥不适用粘质盐土物理性状的改良.因此,改良粘质盐土的关键是选择增加土壤大孔隙数量、比例,提高土壤饱和导水率的材料.
Abstract
To study the effects of different modified materials on the physical properties of clayey saline soil,a field experiment was carried out in the clayey saline soil area of the Yellow River Delta.In this experiment,two sedimentation amounts 20 and 40 t/hm2 and three diatom mud amounts 1.5,3.0 and 4.5 t/hm2 were used,and controlled trials were set up.The effects of different modified materials and amounts on soil bulk density,porosity,saturated hydraulic conductivity,soil water and salt distribution,growth and yield of cotton were analyzed.The results showed that there was no significant difference between soil bulk density and total porosity in 0-20 cm soil layer;the large pore ratio of the three diatom mud treatments decreased by 0.51%,2.53% and 4.75% compared with CK,the saturated hydraulic conductivity decreased by 1.18%,15.88%,22.65%,the soil salt content decreased by 62.76%,72.01% and 75.76%,respectively (P<0.05),and the cotton yield decreased by 2.8%,5.0% and 11.1%,respectively;the large pore ratio of the two sedimentation treatments increased by 17.75% and 37.09% compared with CK,the saturated hydraulic conductivity increased by 17.94% and 60.29%,respectively (P<0.01),the soil salt content decreased by 23.17% and 25.08%,respectively (P<0.05),and the cotton yield increased by 11.1% and 16.7%,respectively.Yellow River sediment could effectively improve the soil texture and pore condition,increase soil saturated hydraulic conductivity,and be suitable for improving the physical properties of clayey saline soil.Diatom mud was not suitable for the improvement of physical properties of clayed saline soil.Therefore,the key points to improve the clayey saline soil were to select the materials that could increase the quantity and proportion of soil macropores and improve the saturated hydraulic conductivity of soil.