棉田废弃物还田对滨海盐碱地土壤质量的影响

棉花是黄河三角洲盐碱地区主要的种植作物。本试验设在利津县毛坨村，利用棉籽、棉秆、废棉等棉田废弃物还田，对盐碱地土壤的物理、化学、生物学指标进行分析，探讨不同棉田废弃物还田对盐碱地土壤质量的影响，为滨海盐碱地改良及棉田废弃物的综合利用提供科学依据。结果表明：（1）与对照相比，棉籽、棉秆、废棉处理的土壤容重均递减，土壤孔隙度、田间持水量递增，并且均达到极显著水平；棉田废弃物还田的土壤pH、含盐量含量明显降低，阳离子交换量、有机质含量明显升高。改良效果呈：棉籽处理＞棉秆处理＞废棉处理。（2）棉田废弃物还田的土壤微生物数量、棉花产量和土壤呼吸强度均比对照明显增加，增加程度依次为：棉籽处理＞棉秆处理＞废棉处理。（3）随着土壤深度增加，改良作用在减弱。总之，棉田废弃物以棉籽改良盐碱地效果最好，棉秆次之。

Effect of the Cotton Field Wastes Returning on the Soil Quality of Costal Saline-Alkaline Land

Cotton is one of the most important crops in saline-alkaline land in the Yellow River delta. The cottonseed, cotton straw and waste cotton were returned to the field in this study in Maotuo, Lijin Country. Meanwhile, the physic-chemical and biological properties were investigated in order to discuss the effect of different wastes, including cottonseed, cotton straw and waste cotton returning to the field on the soil quality of saline-alkaline land. The author expected to provide more scientific materials on improvement and utilization of coastal saline-alkaline land by this study. The results showed that: soil bulk density decreased and soil porosity and field capacity increased in cottonseed treatment (CT), cotton straw treatment (CST) and waste cotton treatment (WCT) compared to control treatment. Meanwhile, pH and the content of soil salt decreased, but cation exchange capacity (CEC) and the content of soil organic matter (SOM) increased. The effect of improvement of saline-alkaline land were in the order: CT>CST>WCT. Compared to control treatment, the quantity of microorganism, yield of cotton and soil respiration intensity increased in the order: CT>CST>WCT. However, the effects of improvement of saline-alkaline land decreased with soil depth. It suggests that the cottonseed is better rather than cotton straw and cotton waste in improvement of saline-alkaline land, and then is the cotton straw.