间套紫花苜蓿对棉花生长发育、产量及棉田土壤微生物和酶活性的影响

Effects of Intercropping Alfalfa on Growth and Yield of Cotton, Microorganism and Enzyme Activities of Cotton Field Soil

为提高河滩地和盐碱地的土壤肥力,实现其植棉减肥增效,在连年种植棉花的河滩沙地(原阳点)和低肥力盐碱地(开封点)进行了棉花和紫花苜蓿间作同时播种(JT1)和棉花现蕾后套种紫花苜蓿(JT2)对棉花生长发育、产量以及棉田土壤微生物和酶活性的影响试验,探索在不减少棉花产量的前提下适宜的间作或套种紫花苜蓿的种植方式。结果表明,与单作棉花(CK)相比,JT1处理棉花生长发育受到明显限制,株高、单株果枝数、单株果节数、单株铃数和铃质量明显降低,单铃不孕子数增加,两试验点子棉产量分别显著减少了20.55%和22.03%;JT2处理棉花生长发育受影响不明显,减产不显著。就两处理对土壤微生物数量和土壤酶活性的影响看,两试验点土壤细菌、真菌和放线菌数量在不同测定时期均较CK显著增加,两试验点土壤蛋白酶、脲酶、磷酸酶、转化酶和过氧化氢酶活性均较CK显著提高,拔棉柴后,两处理土壤有机质、全氮、速效氮、速效磷和速效钾含量均显著高于CK,棉田土壤营养状况得到明显改善,为下茬棉花减肥增效创造良好的土壤条件。可见,棉花和紫花苜蓿同时播种间作对棉花的生长发育影响较大,使棉花子棉产量较单作棉花显著减产,而在棉花现蕾后套种紫花苜蓿对棉花生长发育及子棉产量的影响不显著,但同样达到了显著提高土壤微生物数量、多种酶活性和土壤养分的效果。

In order to improve the soil fertility of river flat and saline-alkali land for planting cotton,and realize the concept of “Reducing the amount of fertilizer applied and increasing the efficiency of fertilization”,the effects of JT1(cotton and alfalfa intercropping at the same day)and JT2(interplanting alfalfa in cotton field after the cotton budding period)treatments on the growth and yield of cotton,microorganism and enzyme activities of cotton field soil were studied in the sandy land (Yuanyang) and low-fertility saline-alkali land (Kaifeng) where cotton was planted year by year,to explore a suitable planting way of intercropping or interplanting alfalfa in cotton field without reducing cotton yield.The results showed that compared with cotton monoculture(CK),the growth and development of cotton of JT1 treatment were restrained significantly.The plant height,the number of fruit nodes per plant,the number of bolls per plant and the boll weight were reduced obviously,and the number of infertile seeds per boll increased.The yield of cotton in the two trials was significantly reduced by 20.55%,22.03%.The growth and development of cotton of JT2 treatment were not affected greatly,and the yield reduction was not significant.According to the effects of the two treatments on soil microbial quantity and soil enzyme activity,the number of soil bacteria,fungi and actinomycetes in the two test ways increased significantly,compared with the control at different measurement periods.The activities of soil protease,urease,phosphatase,invertase and catalase were higher than those of the control group.After the cottonwood was removed,the contents of soil organic matter,total nitrogen,available nitrogen,available phosphorus and available potassium were significantly higher than the control group,which showed that the soil nutrient status had been improved significantly,creating good soil conditions for the “Reducing the amount of fertilizer applied and increasing efficiency” of the next crop of cotton.In conclusion,the planting way of cotton and alfalfa intercropping at the same day had obvious effect on the growth and development of cotton,leading to reduction the yield of seed cotton significantly.However,the planting way of interplanting alfalfa in cotton field after the cotton budding period had no significant effect on the growth and development of cotton and the yield of seed cotton,however,it also achieved the effect of significantly improving soil microbial quantity,soil enzyme activity and soil nutrients.