膜下滴灌棉田土壤水分动态化研究

通过系统观察不同土壤类型棉田水分动态变化规律,研究了膜下滴灌棉花苗期、蕾期、花铃期、吐絮期土壤含水量以及不同土层深度土壤水分的变化。结果表明,沙土和粘土从苗期到吐絮期含水量变化趋势相似,并呈现规律性的变化:土壤含水量的变化趋势近似于抛物线,苗期土壤含水量最低,随棉花的生长发育,土壤含水量逐渐增加,至花铃期达最大,到吐絮期,土壤含水量又下降,与蕾期相当。不同土壤质地0～100cm土层各层次的土壤水分含量存在差异,随着土层深度的增加,土壤含水量呈下降趋势。在不同生育期,沙土的含水量明显低于粘土。这种变化与土壤的物理化学性质、生物学特性以及棉花根系的生长发育有关。

Dynamic Study on Soil Moisture in Differents Soil Texture of Cotton Field Using Drip Irrigation under Film

Dynamic change rules of cotton field moisture in different soil types were observed. Soil moisture content in cotton seedling stage, bud stage, flowering stage and boll-opening stage using drip irrigation under plastic film was studied as well as changes of soil moisture content in different soil layer. Result showed that change tendency of soil moisture contents in sandy soil and the clay were similar from the seedling stage to boll-opening stage. And they presented a regular change with the change tendency of soil moisture content being approximate to the parabola. The moisture content in seedling stage was the lowest. With the growth of cotton, the content gradually increased and reached its maximum in flowering stage. Soil moisture content dropped at boll-opening stage, which was similar with that of bud stage. There were differences among the soil moisture contents in 0~100cm soil layers of different soil textures. Soil moisture content decreased with the increase of soil depth. Soil moisture content in sandy soil was obviously lower than that of clay in different periods, which was affected by the soil physical and chemical properties, biological characteristic and the development of cotton root system.