改良剂对盐化草甸土不同土层理化性质及大豆产量的影响

为解决苏打盐化草甸土大豆种植产量低的问题,实现效益最大化和盐碱土可持续利用,本研究采用大田对比法,设置CK、T1、T2和T3 4个处理,每个处理在常规施肥基础上,分别增施改良剂0,30,60和120 kg·hm^-2,测定土壤相关理化性质和大豆产量,以期明确土壤改良剂对大豆田盐化草甸土的改良效果。研究结果表明:与当地常规施肥处理(CK)相比,T3处理10～40 cm土层容重降幅为3.17%～3.39%,T2和T3处理10～40 cm土层pH降幅分别为1.46%～1.83%和1.59%～2.19%,T2和T3处理0～30 cm土壤交换性钠含量降幅分别为3.08%～4.45%和3.61%～3.98%,T2和T3处理0～30 cm土层电导率、各级别水稳性团聚体百分数和MWD均显著增加,T1、T2和T3处理产量分别增加4.77%、21.94%和25.68%,效益分别增收176.7,953.8和892.5元·hm^-2。综合改良效果及效益,针对本次供试土壤盐渍化程度,改良剂最优用量为60 kg·hm^-2。

Effects of a Soil Ameliorants on Soil Physicochemical Properties with Different Depth Soil Layers and Yield of Soybean in Saline Meadow Soil

In order to investigate the effects of the soil ameliorants on soil physicochemical properties with different soil layers and yield of soybean in saline meadow soil, we conducted a field experiment, four ameliorants application levels as 0, 30, 60, 120 kg·ha^-1, defined as CK、T1、T2、T3, respectively, and the amount of fertilizer applied with the those treatments were the same as the local conventional fertilization treatment. We compared the results of the field experiment with that of CK. T3 substantially reduced soil bulk density of 10-40 cm soil layer by 3.17%-3.39%, pH of 10-40 cm soil layer of T2 and T3 reduced by 1.46%^-1.83% and 1.59%-2.19%, respectively. Exchangeable sodium content of 0-30 cm soil layer of T2 and T3 reduced by 3.08%-4.45% and 3.61%-3.98%. However, compared with CK, T2 and T3 substantially enhanced the electrical conductivity, the proportion of different water stable aggregate size and the mean weight diameter(MWD). T1, T2 and T3 increased yield of soybean by 4.77%, 21.94% and 25.68%, and the benefit increased by 176.7, 953.8 and 892.5 yuan·ha^-1, respectively. Overall, we comprehensived the effect of soil ameliorants on the soda salinized meadow soil and benefit analysis, the optimum application rate for the degree of soil salinization in this experiment was proposed as 60 kg·ha^-1. The results provide theoretical basis for the improvement of soda salinized meadow soil.