【摘要】 以黄土母质生土为供试土壤,采用盆栽试验,研究小麦与3种豆科牧草及油菜混作对根际土壤生物活性及土壤营养的影响.结果表明,黄土母质生土混作较单作可显著促进根际土壤微生物的繁衍、酶活性及土壤营养的提高,且在混作根土系统中,三大微生物种群数量、多种土壤酶活性以及土壤N、P、有机质营养之间均存在显著或极显著的正向相关关系.4种混作处理以豌/麦根际土壤综合效应较好,可作为生土改良的首选混播作物.结果还显示,在小麦生长期内,混作根际微生物数量与酶活性及根际土壤营养均随生育进程呈前低—中高—后低的抛物线变化.研究为混作复合群体应用于黄土母质生土地改良提供了理论参考.图3表1参23更多还原

【Abstract】 In order to investigate the effect of mixture cropping on the improvement of immature loess subsoil,four kinds of potted mixture cropping were applied as: Wheat(Triticum aestivum) + rape(Brassica campestris),wheat + pea(Pisum sativum),wheat + alfalfa(Medicago sativa) and wheat + trefoil(Trifolium pratense) to study the biological activity and nutrition in the immature loess subsoil.The results showed that mixture cropping promoted significantly multiplication of rhizospheric microbes,and increased enzyme activity and soil nutrition in the immature loess subsoil compared with monoculture.In the root-soil systems of mixture cropping,there were significant or extremely significant positive correlation among three types of main microbes,enzyme activities and N,P and organic matters in soil.The type of wheat + pea mixture cropping was the best choice to improve immature loess subsoil because of its comprehensive rhizospheric effects.The results also showed that the rhizospheric microbe quantity,enzyme activity and soil nutrition changed regularly with parabolic curve of lower—higher—lower at wheat growth stage.The study provided theoretical pattern for improving immature loess subsoil under mixture cropping.Fig 3,Tab 1,Ref 23更多还原