Abstract:

【Objective】 To explore the law of water and salt movement in different salinized soil conditions in cotton seedling stage, and clarify the relationship between the seedling formation law of different cotton varieties and soil salinity,the results can provide a theoretical basis for cotton cultivation under salinization conditions.【Methods】 The main cotton varieties in southern Xinjiang Tahe 2, Xinluzhong 56, and Xinluzhong 87 were taken as the research object, a completely randomized pot experiment was arranged in 2021. Three salt gradients shall be set according to the national soil salinization classification standard: 3, 5 and 15 g/kg (designated as S₁, S₂ and S₃ in turn), and the test soil was the original saline soil in Xiaohaizi irrigation area in southern Xinjiang.【Results】 (1) After a period of irrigation, under the condition of the soil salt content of 15 g/kg, the soil moisture content was higher than that of other treatments; (2) The salt content of 0-20 cm soil layer with different salinity treatment was significantly higher than that of 20-40 cm soil layer. With the increase of the initial salt content of the soil, the salt return to the surface layer increased; (3) According to the fitting equation, when the soil salt content of Tahe 2, Xinluzhong 56, and Xinluzhong 87 cotton reached 6.94, 7.04 and 7.09 g/kg, respectively, the number of adult seedlings was 0, which can be used as the salt resistance limit value of cotton in the seedling period.【Conclusion】 When the soil salt reaches the salt resistance limit value, soil permeability is weakened, salt aggravation seriously affects the cotton seedlings. It can be seen that the cotton seedling period responds significantly to the soil salinity, and the cotton planted in saline soil should be controlled by salt water, and soil salt content should be adjusted in time.

Key words: cotton; salinization; rate of water content; soil salt content; water and salt transport

摘要：

【目的】 研究棉花苗期不同盐化土壤条件下水盐运移规律,分析不同棉花品种成苗规律与土壤盐度之间的相关关系,为盐渍化条件下棉花种植提供理论依据。【方法】 以新疆南疆主栽棉花品种塔河2号、新陆中56号、新陆中87号为材料,于2021年布置完全随机盆栽试验,依据全国土壤盐渍化分级标准设置3个盐分梯度:3、5和15 g/kg(依次记为S₁、S₂、S₃),试验土壤为南疆小海子灌区原状盐渍土。【结果】 (1)灌水一段时间后,在土壤含盐量为15 g/kg的条件下,土壤含水率高于其他处理;(2)不同盐度处理0~20 cm土层含盐量都显著高于20~40 cm土层,随着土壤初始含盐量的增加,表层返盐加重;(3)塔河2号、新陆中56号和新陆中87号棉花在土壤含盐量分别达到6.94、7.04、7.09 g/kg时,成苗数为0,可作为棉花苗期耐盐极限值。【结论】 当土壤盐分达到耐盐极限值时,土壤渗透性减弱,返盐加重,严重影响棉花成苗。棉花苗期对土壤盐度响应显著,盐渍土种植棉花应以盐定水,及时调控土壤盐分含量。

关键词: 棉花, 盐渍化, 含水率, 土壤含盐量, 水盐运移