Marginal effect of dry matter accumulation and nitrogen and phosphorus uptake and utilization in maize and soybean intercropping
[Objective]The present paper aimes to study the effects of intercropping on dry matter accumulation,nitrogen and phosphorus ab-sorption and utilization of maize and soybean,and to clarify the mechanism,which has important guiding significance for realizing high yield and high efficiency of maize and soybean intercropping.[Method]Three planting methods were set up in the experiment,namely,maize sin-gle cropping,soybean single cropping and maize and soybean intercropping.Nitrogen and phosphorus accumulation of maize plants at wide-mouth stage,spinnery stage and maturity stage,and nitrogen and phosphorus accumulation of soybean plants at flowering stage,pod stage and maturity stage were measured respectively.The characteristics of dry matter accumulation and nitrogen and phosphorus absorption accu-mulation of different organs of maize and soybean were studied by intercropping,and the marginal effects of nitrogen and phosphorus absorp-tion and utilization were clarified.[Result]Intercropping decreased the accumulation of dry matter and nitrogen and phosphorus,and promo-ted the distribution of nitrogen from roots to grains compared with single cropping.The dry matter accumulation of soybean was reduced,es-pecially the influence on the middle row was greater than that on the side row,and the dry matter and nitrogen and phosphorus accumulation on the side row showed marginal effect advantage.Compared with the mono-cropping system,intercropping reduced the nitrogen transfer a-mount of vegetative organs in stems and leaves of corn and soybean plants by 22.13％and 29.85％,respectively,and the contribution rate of transport nitrogen to corn kernel nitrogen decreased by 5.11％and 17.45％,respectively,and the contribution rate of root nitrogen ab-sorption to grain nitrogen was higher than that of transport nitrogen to grain nitrogen.Intercropping could effectively improve the nitrogen use efficiency of the system,which was 2.34％and 4.62 times higher than that of corn and soybean monocropping,respectively.The nitrogen use efficiency of the system was 26.82％higher than that of soybean monocropping,and 10.16％lower than that of corn monocropping.Corn occupied the dominant position in the system yield,accounting for 82.27％of the system yield,and LER reached 1.47.The system yield was 13 110 kg/hm2,which was 3.96％lower than that of monocroping maize.[Conclusion]The main advantage of intercropping is to promote the distribution of nitrogen absorbed by roots to grains and improve the efficiency of nitrogen use.
MaizeSoybeanIntercroppingNitrogen use efficiencyMarginal effect
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万方数据
