为了分析咸水灌溉的可行性,试验于衡水市开展连续多年的大田定位咸水灌溉试验。以2012年棉花生长季为例,研究采用不同矿化度咸水灌溉后,不同灌水技术对土壤理化性状、土壤酶活性和棉花产量的影响。结果表明,咸水畦灌和沟畦轮灌均造成土壤积盐,其中沟畦轮灌处理在沟灌时的脱盐效果比畦灌处理好。随灌溉水矿化度的增加,0-20cm土层的土壤盐度、容重和pH表现出增加的趋势;畦灌处理的土壤盐度和pH整体高于相应的沟畦轮灌处理,但土壤容重较低。畦灌处理的土壤有机质含量在试验初期和结束时分别比相应的沟畦轮灌处理高8.9%~16.0%和13.8%~19.4%。2种处理土壤转化酶的恢复能力表现最强,脲酶相对稳定;在相同的土壤盐度水平下,畦灌处理的土壤酶活性整体高于沟畦轮灌处理。随土壤盐度的增加,畦灌处理的籽棉产量先增加后减少,而沟畦轮灌处理线性降低。当土壤盐度低于0.8dS/m时,畦灌处理的籽棉产量高于沟畦轮灌处理,反之则低。由以上分析可知,咸水灌溉导致土壤积盐、土壤酶活性受抑、pH和表层土壤容重增加;与畦灌相比,沟畦轮灌处理的土壤盐度水平更低,且具有更好的脱盐效果,但是因种植方式差异导致耕层土壤容重增加,有机质含量和土壤酶活性降低,籽棉产量低于畦灌处理。
In order to analyze the feasibility of the saline water irrigation, an experiment was conducted under long-term location saline water irrigation in Hengshui. The effects of border irrigation and alter furrow and border irrigation with saline water on soil physical-chemical properties and activities of soil enzyme, and cotton yield after continuous seven years irrigation during the cotton growing season in 2012 were studied. Results showed that border irrigation and alter furrow and border irrigation with saline water both led to salt accumulation in the soil profile, and the desalinization level was better in alter furrow and border irrigation treatment under furrow irrigation. With the increasing salinity of irrigation water, the soil salinity, soil bulk density, and pH value in 0--20 cm soil layer increased. Compared with alter furrow and border irrigation treatment, the soil salinity and pH value of the corresponding border irrigation treatment were higher, while the soil bulk density was lower. Soil organic matter of border irrigation treatment at the initial and final stage of experiment was higher than that of corresponding alter furrow and border irrigation treatment by 8.9 % 16.0% and 13.8% - 19.4%, respectively. The recovery capability of soil invertase activity was strong in two irrigation treatments, but urease activity was relatively stable. Soil enzyme activity of border irrigation treatment washigher than that of alter furrow and border irrigation treatment when the soil salinity was the same. With the increasing soil salinity, the seed cotton yield of border irrigation treatment first increased and then decreased, while the yield of alter furrow and border irrigation treatment decreased linearly. The seed cotton yield of border irrigation treatments were higher than that of alter furrow and border irrigation treatments when the soil salinity was the same and lower than 0.8 dS/m. The opposite was lower. By the analysis above, it was concluded that saline water irrigation led to soil salt accumulatio