苜蓿与禾草混播对海流图盐碱地土壤改良效果研究

Effect of Alfalfa-grass Mixed Pasture On the Remediation of Soil in Saline Area of Hailiutu

为探求不同混播组合和混播比例对盐碱土壤的影响,筛选最适合海流图盐碱地的混播方式,本研究以杂花苜蓿(Medicago varia)分别与新麦草(Psathyrostachys juncea)、缘毛雀麦(Bromus ciliatus)和长穗偃麦草(Elytrigia elongata)混播建植草地,连续三年测定土壤养分含量和pH,结果表明,建植混播草地对土壤有机质、全氮、速效磷、速效钾积累都有显著促进作用,降低土壤pH效果显著。苜蓿与新麦草混播最有利于土壤速效钾的积累,苜蓿与缘毛雀麦混播最有利于土壤有机质、氮素、速效磷的积累,苜蓿与长穗偃麦草混播降低土壤pH效果最显著。对于该地区同类型盐碱地综合改良效果而言,短期以苜蓿-长穗偃麦草1∶2混播土壤改良效果最好,长期以苜蓿-缘毛雀麦1∶2混播土壤改良效果最好。

In order to evaluate the remediation effects of different mixed sowing combinations and mixed sowing ratios on saline-alkali soil,and screen the best mixed sowing method for the saline-alkali soil of Hailiutu,27 mixed sowing plots were established using Medicago varia(alfalfa)with Psathyrostachys juncea,alfalfa with Bromus ciliatus and alfalfa with Elytrigia elongata.The soil nutrient contents and pH were measured for three consecutive years.The results showed that the mixed sowing of legume and grass had a significant effect on the accumulation of soil organic matter,total nitrogen,available phosphorus and available potassium,and reduction of soil pH value.The combination of alfalfa mixed with P.juncea was more conducive to the accumulation of soil available potassium.The combination of alfalfa mixed with B.ciliatus was more conducive to the accumulation of soil organic matter,nitrogen and available phosphorus.The mixed sowing of alfalfa and E.elongata had the most significant effect on reduction of soil pH value.For the same type of saline-alkali soil in the Hailiutu area,the short-term remediation effect of alfalfa-E.elongate mixture with 1∶2 sowing ratio is the best,and the long-term remediation effect of alfalfa-B.ciliates mixture with 1∶2 sowing ratio is the best.