Relationship between the forms of soil sodium and sodium absorbed by cotton in the south centre area of Hebei

The soil sodium forms and content of 36 samples were investigated in south centre area of Hebei. The results showed that the total sodium, exchangeable sodium and water-soluble sodium contents in the 0-20 cm soil layer were 10.7-24.6, 48-10250 and 21.5-10400.5 mg/kg respectively. The relationship between the total sodium with exchangeable sodium, water-soluble sodium and exchangeable sodium with water-soluble sodium in soil were positive correlation; and the total sodium with soil organic matter, soil ECE were negative, and the total sodium with soil water-soluble sodium in irrigated cotton was also negative. The pot experiment by using the investigated soils indicated that the relationship of dry matter accumulation of cotton at seedling with soil exchangeable sodium and soil water-soluble sodium; and soil sodium absorption rate with exchangeable sodium and water-soluble sodium of cotton plant at seedling stage were curvilinear correlation.