玉米/大豆间作模式对青贮玉米产量、品质及土壤营养、根际微生物的影响

为明确冀西北地区玉米/大豆间作模式(简称玉豆间作模式)对青贮玉米产量、品质及土壤微生物群落的影响,以青贮玉米中原单32与大豆绥农41为材料,于2017—2018年进行了5种不同间作模式种植试验,测定了青贮玉米产量、品质以及土壤营养与微生物的变化。结果表明,与玉米单种(CK)相比,玉豆间作能明显提高青贮玉米产量、品质,改善土壤营养和微生物菌落。玉豆2:1模式为该地区最佳间作模式,该模式青贮玉米产量为68.53 t·hm^-2,粗蛋白(CP)、淀粉含量明显增加,分别比CK多0.5和3.2个百分点;每吨干物质可生产的牛奶量达到1 539.00 kg·t^-1。与CK相比,玉豆间作下根瘤菌固氮作用明显,其中玉豆2:1模式下灌浆期根际土壤碱解氮含量为124.3 mg·kg^-1。此外,在玉豆间作模式中,玉米根际土壤中子囊菌门真菌表达丰度增加,担子菌门真菌表达丰度降低;出现柄孢壳菌、Harpophora radicicola等新真菌类型。玉豆2:1模式下玉米根际土壤微生物OTU最多,达到318个。本研究为冀西北地区开展高产、优质玉豆栽培技术模式提供了理论依据。

Effects of Corn/Soybean Intercropping Model on Yield,Quality, Soil Nutrition and Rhizosphere Microorganisms of Silage Corn

The purpose of this study was to clarify the effect of corn/soybean intercropping pattern on the yield, quality and soil microbial community of silage corn in the north-west of Hebei province. Taking corn Zhongyuandan 32 and soybean Suinong 41 as materials, five different intercropping patterns were tested in 2017 and 2018. The yield and quality of silage corn, the change of soil nutrient and microorganism were measured. Compared with maize corn monocropping (CK), the corn/soybean intercropping pattern could obviously improve the yield and quality of silage corn. Meantime, the soil nutrient and microbial colonies were also modified. The 2:1 cultivation mode was the optimum mode. In this mode, the yield of silage corn was 68.53 t·hm^-2, and the content of crude protein and starch increased significantly, which was 0.5 and 3.2 percent higher than CK, respectively. The weight of milk that can be produced per ton of dry matter reached 1 539 kg·t^-1. Compared with CK, the nitrogen fixation effect of rhizobium in the corn/sybean intercropping pattern was obvious. In the 2:1 cultivation mode, the content of N in rhizosphere soil reached 124.3 mg·kg^-1. Meantime,in the corn/soybean intercropping pattern, the relative abundance of Ascomyces was increased, while the relative abundance of Basidiomycetes was decreased.The new fungal types such as Podospora tetraspora and Harpophora radicicola were obtained in the corn/soybean intercropping pattern. The number of OTU in the 2:1 cultivation mode was the most reaching 318. This study provides experimental basis for the corn/soybean intercropping cultivation technology model for high yield and high quality in northwest Hebei.