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为探究不同秸秆覆盖量对盐渍化土壤蒸发量、含水率及含盐量的动态变化规律,于2009年在陕西省蒲城县卤泊滩试验基地进行了4个水平的秸秆覆盖量(1.05,0.75,0.45,0.15kg/m2)试验,以不覆盖为对照(C0)。试验结果表明:4个处理盐渍化土壤的日平均蒸发量较C0均显著减少,分别减少1.335 8,1.310 3,1.035 7,0.629 0mm/d;随着时间的延长,各土层土壤含水率逐渐增加,10cm土层平均土壤含水率变化幅度最大,较C0分别增加9.280%,9.000%,6.920%,2.450%;随着时间的延长,10,30cm土层土壤含盐量逐渐减少,盐分逐渐压制在50cm土层,10cm土层平均土壤含盐量变化幅度最大,较C0分别减少0.811%,0.802%,0.723%,0.381%;当秸秆覆盖量为0.75kg/m2时,再增加秸秆用量,保水和抑制盐分表聚的作用并无明显增强。研究表明,采用秸秆覆盖地表改良盐渍化土壤,减少了土壤水分蒸发损失,提高了水分利用效率,抑制了盐渍化土壤可溶性盐分的表聚作用,有效地提高了耕地面积的利用,且秸秆覆盖量以0.75kg/m2为宜。
In order to explore the dynamic changes of soil salinity, water content and salinity under different straw mulching rates, four levels of straw mulching (1.05 , 0.75, 0.45, 0.15 kg / m2) to not cover the control (C0). The results showed that the average daily evaporation of four salinized soils was significantly lower than that of C0, decreasing by 1.335 8, 1.310 3, 1.035 7 and 0.629 0 mm / d, respectively. With the extension of time, the soil moisture The average soil water content of 10cm soil layer changed the most, which increased by 9.280%, 9.000%, 6.920% and 2.450% respectively compared with that of C0. With the extension of time, the salt content of soil in 10 and 30cm soil gradually decreased, In the 50cm soil layer, the average soil salt content in the 10cm soil layer was the largest, which was 0.811%, 0.802%, 0.723% and 0.381% less than that of C0. When the straw mulching amount was 0.75kg / m2, Water retention and inhibition of salt aggregation did not significantly enhance the role. The results showed that using straw to cover the surface to improve salinized soil reduced the loss of soil water evaporation, increased water use efficiency, suppressed the surface aggregation of salinity soluble salt and effectively increased the utilization of arable land, and straw Coverage to 0.75kg / m2 is appropriate.