The effects of mixed planting of leguminous and gramineous green manure crops on fresh bi-omass and soil properties were investigated with a four-factor simple center mixture design. The mixture of vetch, hairy vetch and millet, with seeding rate 75. 0kg/hm2, 30kg/hm2 and 20kg/hm2 respectively, was one of the most productive patterns. After sowed in mixture during wheat flowering time, fresh biomass of all three crops yielded over 36138kg/hm2, which was 34. 6% , 1. 9% and 156.3% more than those of monoculture of vetch, hairy vetch and millet separately. The residues of roots in the mixture was 3534kg/hm2, which was 81. 4% ,67. 2% and 28. 9% more than those of corresponding monocultured vetch, hairy vetch and millet, respectively. The soil fertility of the mixture was improved, compared with three monoculture cropping. Soil organic matter, total N, available N, available P in the mixture were increased by 0. 148 ~ 0. 43g/kg,-0. 44 ~ 0. 11g/kg, 2. Lmg/kg and lmg/kg, respectively, and bulk density was decreased by 0. 01 ~0. 02g/cm3, and soil porosity was increased by 0. 33%~0. 66%, compared with corresponding monocultured cropping. The results indicated that technique of leguminous and gramineous mixed sowing increases fresh forage biomass and root residues, and improves soil fertility and physical properties.%采用四因素单形重心混料设计,对豆科与禾本科绿肥作物混播增肥改土效果及其混播技术进行研究,结果表明:箭筈豌豆、毛苕子、谷子混播为最佳混播方式,其用种量为箭筈豌豆75.0kg/hm2、毛苕子30kg/hm2、谷子20kg/hm2,在小麦扬花期撒播,鲜草产量可达36138kg/hm2,较单播箭筈豌豆、毛苕子、谷子分别增产34.6％、1.9％、156.3％；鲜根量可达3534kg/hm2,较单播箭笤豌豆、毛苕子、谷子分别增加81.4％、67.2％、28.9％.混播区较单播区土壤有机质含量增加0.148～0.43g/kg,全氮增加-0.04～0.11g/kg,碱解氮增加2.1mg/kg,速效磷增加1mg/kg,全磷基本保持平衡,土壤容重减轻0.01～0.02g/cm3,土壤孔隙度提高0.33％～0.66％.
展开▼
