间作促进作物磷吸收的氮素调控效应

为探讨通过氮素调控促进间作作物磷吸收利用的效果，阐明间作的氮磷交互作用机理。设置3种种植模式（玉米马铃薯间作、玉米单作和马铃薯单作）、4个施氮水平（N0：不施氮、N1：1/2常规量、N2：常规量、N3：3/2常规量）的田间小区定位试验，研究玉米马铃薯间作对作物磷吸收和利用的影响，并分析磷吸收对施氮量的响应。结果表明：施氮量显著影响间作产量，低氮（N1）水平间作产量优势最大。间作玉米和马铃薯的磷吸收量均随施氮量增加而降低，在N2水平达到最大。在低氮条件下，间作玉米磷吸收量较单作平均提高了42.03%，马铃薯提高了13.46%。随施氮量的增加，玉米马铃薯间作的单位面积磷吸收的优势呈先增加后下降的趋势，在N1水平优势最强。在N1水平中，与单作相比，间作玉米籽粒磷吸收量平均增加86.26%，间作马铃薯块茎磷吸收量平均增加14.28%。因此，在保证作物产量和提高氮磷肥利用率的前提下，合理施入氮肥能够促进间作作物对磷素的吸收与利用。

Regulation effect of nitrogen application on promotion of phosphorus uptake of crops under intercropping

It is of great significance to explore how nitrogen regulation promotes phosphorus absorption and utilization in intercropped crops for elucidating interaction mechanism of nitrogen and phosphorus and nitrogen management in intercropping. Effects of intercropping on absorption and utilization of phosphorus, and its response to nitrogen were analyzed through field plot experiment with 3 planting patterns (maize and potato intercropping and corresponding monoculture) and 4 nitrogen levels including no nitrogen fertilizer (N0), 50% of regular nitrogen amount (N1), regular nitrogen amount (N2) and 150% of regular nitrogen amount (N3). The results showed that nitrogen application significantly affected yield advantage of intercropping, and low nitrogen (N1) had the greatest yield advantage. Phosphorus uptake of intercropped maize and potato decreased with the increase of nitrogen application rates, and phosphorus uptake was the largest at N2 level. Compared with corresponding monoculture at N1 level, phosphorus uptake in intercropped maize and intercropped potato increased 42.03% and 13.46%, respectively. Advantages of phosphorus absorption per unit area in intercropping system increased firstly and then decreased with the increase of nitrogen application rates, and the advantages were the strongest at N1. Absorbed phosphorus by maize concentrated mainly in grain, followed by straw and root, while phosphorus by potato in tubers. Compared with monoculture at N1 level, grain phosphorus in intercropped maize increased averagely 86.26% while averaged uptake by tubers of intercropped potato increased 14.28%. Therefore, the rational nitrogen application can promote the increasing effect of intercropping on phosphorus absorption and utilization on the premise of ensuring crop yield and improving the utilization rate of nitrogen and phosphate fertilizer.