小麦／玉米间作优势及地上部与地下部因素的相对贡献研究

采用田间微区试验以及地下部种间根系分隔技术研究了玉米覆膜与不覆膜两种情况下小麦/玉米间作优势及地上部因素和地下部因素对间作优势的相对贡献。结果表明,玉米不覆膜时小麦/玉米间作籽粒产量和生物产量土地当量比分别为1.30、1.29,具有明显的产量间作优势,玉米覆膜时小麦/玉米间作籽粒产量和生物产量土地当量比分别为1.41、1.40,具有极显著的产量间作优势;玉米不覆膜时小麦/玉米间作氮、磷、钾养分吸收优势明显,玉米覆膜时小麦/玉米间作具有极显著的氮、磷、钾养分吸收优势。地上部因素和地下部因素对小麦/玉米间作中籽粒产量和生物产量间作优势的相对贡献,当玉米不覆膜时分别为75%、25%,当玉米覆膜时均为地上部占67%、地下部占33%。当玉米不覆膜时,地上部和地下部因素对小麦/玉米间作氮、磷养分吸收优势的相对贡献均分别为67%与33%,钾则地上部与地下部贡献相等(各占50%);当玉米覆膜时,地上部和地下部因素对小麦/玉米间作氮、钾养分吸收优势的相对贡献均具有同等重要性(各占50%),对磷吸收的贡献分别占55%与45%。

Intercropping advantage and contribution of above-ground and under-ground interactions in wheat-maize intercropping

A micro plot experiment and a root barrier technique were employed to investigate the intercropping advantage and the relative contribution of aboveground and under-ground interactions to the yield and nutrient uptaking in the wheat-maize intercropping system with or without plastic sheet mulching.The results showed that the land equivalent ratios(LERs) of both grain yield and biomass were 1.30 and 1.29 respectively for the intercropping of wheat and maize without plastic sheet mulching,showing a evident yield advantage of the intercropping.However,LERs with plastic sheet mulching were 1.41 for grain yield and 1.40 for biomass,indicating a significant yield advantage of the intercropping.There was evident advantage of nutrient uptaking in the intercropping of wheat and maize without plastic sheet mulching,whereas there was greatly significant advantage of nutrient uptaking in the intercropping with plastic sheet mulching.The contributions of above-ground and under-ground interactions to the intercropping advantage of both grain yield and biomass were 75% and 25% respectively for the intercropping without plastic sheet mulching.However,results of both grain yield and biomass were 67% and 33% respectively for the intercropping with plastic sheet mulching.The contribution of above-ground and below-ground interactions to the increase of nutrient uptaking were 67% and 33% for nitrogen,67% and 33% for phosphorus,50% and 50% for potassium respectively when intercropped maize was not mulched with plastic sheet.However,results of nutrient uptaking were 50% and 50% for nitrogen,55% and 45% for phosphorus,50% and 50% for potassium respectively when intercropped maize was mulched with plastic sheet.