基于棉花-水-盐生产函数的耕地盐碱化分级与评价

Grade and Evaluation of Arable Land Salinization Based on Cotton-Water-Salt Production Function

通过建立棉花-水-盐生产函数，对绿洲灌区耕地盐碱化程度进行了划分和评价。结果表明，棉花苗期土壤临界电导率和可容忍电导率分别为6．8dS／m和22．11dS／m，比联合国粮农组织（FAO）推荐的棉花全生育期平均值均低。根据棉花苗期耐盐性及相对产量可初步划分耕地盐碱化程度为6级，棉花适宜在土壤含盐量0．43％以下生长，把0～60cm土壤剖面的盐分控制在0．29％～0．43％即可获得正常产量的85％。在合理的灌排措施下，把中度盐化的土壤改良至轻度是完全有可能的。

Salinization of arable land is a direct threat to the sustainable development of irrigated agriculture in arid areas. In this paper, based on the establishment of cotton-water-sah production function, salinization level of arable land in oasis irrigation areas was divided and evaluated. The results showed that critical and tolerant soil electrical conductivity for cotton was 6.8 dS/m and 22.11 dS/m, respectively. It was less than average value for whole cotton growth period respectively recommended by Food and Agriculture Organization （FAO）. According to the salt tolerance and relative yield of cotton, salinization degree of arable land was preliminarily divided into six grades, and suitable soil salt content for cotton was below 0.43 percent. 85% of normal production could be obtained if salt content in 0-60 cm soil profile were controlled to within 0.29 to 0.43 percent. It is entirely possible that moderate soil salinization is improved to slight through reasonable measures of irrigation and drainage. The division and evaluation of salinization degree of arable land is realized by the study on crop-water-salt production function.