Effects of Nitrogen Application on Nitrogen Accumulation and Distribution of Crops in Maize and Potato Intercropping

Field experiment was carried out to study the effects of 4 nitrogen (N) levelsmaize:N0(0 kg/hm2), N1(125 kg/hm2), N2(250 kg/hm2), N3(375 kg/hm2), potato:N0(0 kg/hm2), N1(62.5 kg/hm2), N2(125 kg/hm2), N3(187.5 kg/hm2)on the yield, biomass, N accumulation and distribution in grain, stem and leaf, root of crops in maize and potato intercropping. The results showed that the maize and potato intercropping had yield advantages and the land equivalent ratios (LER) of 4 N levels were 1.46, 1.20, 1.04, 0.92, respectively. The intercropping yield advantage decreased with increasing of nitrogen level. The intercropping maize N absorptions of grain, stem and leaf, root were 39.76%, 27.98%, 15.36% higher than monocropping, respectively. The intercropping potato N absorption of tuber, stem and leaf was 4.14%, 24.59% lower than monocropping, respectively. Two years of experiment showed that the intercropping advantage of crop nitrogen absorption decreased with the increasing of nitrogen level. The effect of intercropping and nitrogen fertilizer on nitrogen distribution proportion of organs in corn and potato was not significant. The maize and potato yields of intercropping in low N level can catch up with those of monoculture in conventional or excess N level, so maize and potato intercropping can improve the crop yield and efficiency of nitrogen fertilizer, and reduce the nitrogen fertilizer application.