新疆连作棉田耕层土壤理化指标研究

以新疆长期连作棉田为研究对象,通过田间调查、取样测定的方法,研究新疆连作棉田不同产量水平条件下土壤理化指标变化特征。结果表明：随着棉花产量增加棉田耕层深度、犁底层厚度均呈增加趋势,但不同产量水平差异未达显著水平。土壤紧实度、土壤容重和土壤含盐量则呈下降趋势,其中高产田土壤紧实度在10-46cm显著低于中、低产田,而高产田耕层土壤容重和土壤含盐量显著低于中、低产田,但高产田土壤粘粒较中、低产田有所提高,而一定比例的粘粒有利于提高土壤保水性。高产田耕层土壤有机质、速效氮含量较高,表现为高产田>中产田>低产田,而速效磷、速效钾无显著差异。从产量构成因素来看,单株铃数是影响产量的主要因素,其次是单铃重,衣分无明显变化。

Topsoil Physical and Chemical Indexes of Continuous Cropping Cotton Field in Xinjiang

The authors studied the change characters of soil physical and chemical indexes of continuous cropping cotton fields with different yield levels by the methods of field investigation and sampling. The results showed that with the increase of cotton yield, the depth of plough layer and the thickness of plough bottom both increased, but the difference was not significant; soil compaction, bulk density and salt content all appeared decreasing trends, soil compaction of high yield field was significantly lower than that of middle and low yield fields in 10-46 cm soil layer, topsoil bulk density and soil salt content of high yield field were significantly lower than that of medium and low yield fields, but compared with medium and low yield fields, soil clay of high yield field increased, and certain percentage of clay could improve soil water retention. Topsoil organic matter and available nitrogen content of high yield field were higher, which followed the order of high yield field＞ middle yield field＞ low yield field, but no significant difference was found between available phosphorus and available potassium. From the point of yield components, boll number per plant was the main factor that affected production, followed by single boll weight, and lint had no obvious effect.