Abstract: 【Objective】 The effects of different cultivation years alfalfa and alfalfa/cotton rotation on the physical and chemical properties were studied in the Aksu area of Xinjiang.【Method】The soils were collected from 0-10 cm, 10-20 cm and 20-40 cm depth from different plots, including 5 years of continuous planting of cotton field, five years alfalfa rotation planting cotton field, and planting alfalfa from 1st year to 4th year field. The soil bulk density, total salt, organic matter, total nitrogen, alkali hydrolyzable nitrogen, available phosphorus and available potassium were measured.【Result】The rotation can reduce pH. Planting alfalfa can decrease SBD. The SBD was reduced with increased alfalfa planting years. The longer the planting time, the better the SBD effect. The surface layer SBD was highest than that of other layers. The content of total salt (TS) was reduced in planting alfalfa and alfalfa rotation cotton field. The longer the alfalfa cultivation period, the more obviously the TS reduction. The TS in the fourth year of alfalfa field was decreased by 50.5% than that of the first year alfalfa. The TS of alfalfa rotation cotton was reduced by 41.7% than that of continuous cropping cotton. Planting alfalfa can increase the soil organic matter (SOM), the SOM was increased obviously with the increased alfalfa planting years. The total nitrogen content was highest in alfalfa/cotton rotation plot than others. The total nitrogen content of 0 -10 cm soil was highest in planting alfalfa plots than those of 10-40 cm, and 10-40 cm, total nitrogen content was not changed obviously. The alkaline hydrolysis nitrogen, available phosphorus content were highest in 4th year planting alfalfa field. The available potassium content was increased gradually with alfalfa planting years prolonged. 【Conclusion】Planting alfalfa in Aksu area can significantly reduce soil bulk density, increase the soil organic matter and nitrogen content of alfalfa, and alfalfa / cotton rotation can reduce soil salinity.

Key words: alfalfa; rotation; cotton; soil; physical and chemical properties

摘要： 【目的】研究阿克苏地区不同种植年限紫花苜蓿和苜蓿/棉花轮作,对土壤理化性质的影响。【方法】采集种植1~4 a的紫花苜蓿地、连作5 a棉花地和第5 a苜蓿轮作棉花地的0~10、10~20和20~40 cm土壤,测定土壤容重、全盐、有机质、全氮、碱解氮、速效磷和速效钾。【结果】紫花苜蓿与棉花轮作能够降低pH;土壤容重随苜蓿种植年限的增加而降低,并且种植时间越长,改善效果越好;棉花连作土壤全盐含量最高,种植苜蓿和苜蓿与棉花轮作可以降低土壤全盐,苜蓿种植时间越长,土壤全盐降低越明显,苜蓿种植第四年全盐量比第一年降低50.5%,苜蓿/棉花全盐比棉花连作降低了41.7%;土壤有机质含量随苜蓿种植年限增加而增加;苜蓿/棉花轮作土壤土全氮含量最高,种植苜蓿地0~10 cm全氮含量呈增加趋势;种植苜蓿第四年的土壤碱解氮及速效磷含量最高,速效钾随苜蓿种植年限的增加而逐渐增加。【结论】阿克苏地区种植紫花苜蓿可显著降低土壤容重,增加土壤有机质和氮素含量,苜蓿、苜蓿/棉花轮作能够降低土壤盐分。

关键词: 苜蓿, 棉花, 轮作, 土壤盐分, 理化性质