不同混播方式下燕麦+箭筈豌豆混播草地的生产性能及土壤养分特征

Effect of different sowing patterns on production performance and soil nutrients in Avena sativa + Vicia sativa mixtures

为阐明混播方式对燕麦(Avena sativa)+箭筈豌豆(Vicia sativa)型豆禾混播草地混播优势的影响,在新疆昭苏盆地采用同行混播、异行混播与不同豆禾比的播种方式建植混播草地,利用牧草产量、营养物质产量和籽粒产量等指标分析混播方式对生产性能优势的影响,以不同混播方式下土壤养分变化与生产性能的内在联系为依据,探讨生产性能优势获得的途径。结果表明,1)燕麦与箭筈豌豆混播可获得混播优势,其中同行混播+豆禾比50∶50、异行混播+豆禾比50∶50和同行混播+豆禾比75∶25组合牧草产量和种子产量优势明显,生产性能较高。2)混播方式对土壤有机质和土壤全量养分影响较小,单播燕麦具有较高的土壤浅层速效磷含量,箭筈豌豆的生物固氮作用可增加土壤氮素养分的供应,而同行混播方式则有利于土壤碱解氮的积累。3)以混播群体结构作为控制因素时,牧草和粗蛋白产量依赖土壤氮素养分,与土壤速效磷含量呈负相关关系;以混播比例作为控制因素时,高箭筈豌豆混播比例下(80%和100%),土壤氮素养分可负向影响牧草和粗蛋白产量、牧草产量优势,否则则为正向影响,土壤速效磷含量负向影响牧草和粗蛋白产量、产量优势,正向影响种子产量优势,与混播比例无关联。因此,在冷凉牧区进行燕麦+箭筈豌豆型混播草地建植时,采取同行混播+豆禾比75∶25的混播组合既能提高土壤肥力,还能收获牧草产量和品质较优的草产品。

The productivity performance of legume –grass mixtures was analyzed by comparing forage yield, forage nutrients, seed yield, and soil nutrients inVicia sativa + Avena sativa mixtures with different sowing patterns (mixed cropping, intercropping, and different mix ratios). The effects of sowing pattern on the relationships between soil nutrient characteristics, productivity performance, and the advantages of mixed sowing were discussed. The results showed that 1) V.sativa + A. sativa mixtures can gain advantages from mixed sowing. The legume : grass mix ratios of 50 : 50 with mixed cropping, 50 : 50 with intercropping, and 75 : 25 with mixed cropping all displayed obvious advantages in forage yield and seed yield. 2) Mixed sowing patterns had little effect on soil organic matter or soil total nutrient content. Monocultures of A. sativa had higher soil available phosphorus contents. The biological nitrogen fixation of V. sativa increased the supply of soil nitrogen, and mixed cropping is therefore beneficial for the accumulation of soil alkali nitrogen. 3) When a mixed community structure was used as a control factor, forage yield and crude protein yield were dependent on soil nitrogen nutrition and negatively correlated with soil available phosphorus. When a mixed, high V. sativa ratio (80% and 100%) was used as a control factor, soil nitrogen nutrition negatively affected forage yield, crude protein yield, and forage yield advantage. At lower ratios the relationships were positive. Soil available phosphorus negatively affected forage yield, crude protein yield, and yield advantage, but positively affected grain yield advantage, and showed no correlation with mixed planting proportion. In conclusion, A. sativa + V. sativa mixtures with a legume : grass mix ratio of 75 : 25 with a mixed cropping pattern conferred higher mixed advantages in these cool climate pastoral areas. The mixed pattern could not only improve soil fertility, but also increase harvest forage yield and improve the quality of grass products.