桔梗间作模式中作物养分吸收和利用对间作优势的贡献

Uptake and Conversion Efficiencies of NPK and Corresponding Contribution to Intercropping Advantage in Platycodon grandiflorum Based Intercropping Systems

设置桔梗/大葱、桔梗/薄荷间作以及各个作物单作的田间实验,以期揭示以桔梗为主间作体系的养分吸收和利用效率对间作优势的贡献。结果表明,桔梗/大葱间作体系作物的氮钾吸收量分别高于单作1.07%、19.48%,桔梗/薄荷间作体系作物的氮钾吸收量分别低于单作15.79%,1.33%。两种间作体系磷吸收量分别增加0.67%、0.69%。桔梗/大葱间作的土地当量比1.21,说明具有间作优势,桔梗为优势种,竞争能力大于大葱,有利于提供桔梗产量。桔梗/薄荷间作的土地当量比为0.93,说明无间作优势。桔梗/大葱间作体系氮磷钾吸收效率对土地当量比的贡献分别为0.05、0.04和0.23,利用效率的贡献分别为0.39、0.38和-0.04,说明桔梗/大葱间作优势的营养学基础主要来自于氮磷利用效率和钾吸收效率的提高。桔梗/薄荷间作体系氮磷钾吸收效率对土地当量比的贡献相对于单作体系分别降低了0.23、0.13和0.12,表明桔梗/薄荷间作无间作优势主要是间作降低了养分吸收量。

The uptake and conversion efficiency of N,P and K were assessed in Platycodon grandiflorum /Allium fistulosum L.,P.grandiflorum/Mentha arvensis L.intercropping system,and the corresponding monocropping systems,the intercropping advantage and nutrient uptake and conversion of cropping system were determined.The results showed that compared with weighted mean of monocultured crops of sole cropping system,P.grandiflorum/A.fistulosumincreased N and K uptake by 1.07%,19.48%.However,P.grandiflorum/M.arvensis decreased N and K uptake by 15.79%,1.33%,respectively.Phosphorus uptake under intercropping systems of P.grandiflorum/A.fistulosumand P.grandiflorum/M.arvensis were higher than those under the corresponding sole cropping systems by 0.67% and 0.69%,respectively.The equivalent ratio of P.grandiflorum/A.fistulosum was1.21 and P.grandiflorum was the dominant species with more competitive ability relative to A.fistulosum,indicating a significant intercropping advantage and favoring increase yield of P.grandiflorum.However,it was 0.93 in P.grandiflorum/M.arvensis intercropping system,indicating no intercropping advantage.The contributions of the uptake efficiencies of N,P and K were 0.05,0.04 and 0.23 in P.grandiflorum/A.fistulosumintercropping system and the corresponding conversion efficiencies were 0.39,0.38and-0.04,respectively,indicating that the intercropping advantage of P.grandiflorum/A.fistulosumintercropping system was mainly from enhanced N and P conversion efficiency and K uptake efficiency.The contribution of the uptake efficiencies of N,P and K were-0.23,-0.13and-0.12,consequently,it could be the main reason why no intercropping advantage were existed in P.grandiflorum/M.arvensis intercropping system.