Effects of chemical regulation and P fertilization on P absorption and utilization in maize/peanut intercropping system

In order to investigate the effects of chemical regulation and phosphorus (P) fertilization on P in maize/peanut intercropping system, a field experiment was conducted in 2012 and 2013 in the farm of Henan University of Science and Technology. P content, accumulation and distribution in different organs of intercropped maize and peanut were determined and the effects of chemical regulation and P fertilization on intercropped maize/peanut analyzed. The experiment included eight treatments — monocultured maize, monocultured peanut, intercropped maize/peanut with chemical regulation, and intercropped maize/peanut without chemical regulation of 4 planting models with and without P fertilizer application P fertilizer dose was 180 kg(P₂O₅)·hm^–2. Results showed that compared with monocropping system of maize, maize/peanut intercropping system increased seed P content and accumulated P in stem and seed of maize. Also while intercropping enhanced P distribution in maize seed, it obviously limited P content and accumulation in different organs of peanut and P distribution to nuts. Compared with monoculture systems, intercropping improved P uptake with obvious P intercropping advantages of 15.9919.54 kg(P)·hm^–2. During the little bell mouth stage, spraying chemical regulator to intercropped maize increased P content in maize seed, decreased P accumulation in maize stem, leaf and seed, and then promoted P distribution in maize seed. However, spraying chemical regulator to intercropped maize obviously increased P content in seed, P accumulation in stem, leaf and nut, and then promoted P distribution in nut of peanut intercropped with maize. Compared with spraying chemical agent to intercropped maize without P fertilization, spraying chemical agent to intercropped maize with P fertilization significantly enhanced P content and accumulation in different organs of maize and peanut, increased P distribution in maize seed and peanut nut. Also compared with none-P intercropping, intercropping with P fertilization improved P absorption of the system, and increased P intercropping advantage to 19.5022.00 kg(P)·hm^–2, representing an increase of 16.51%57.51%. This suggested that the application of P fertilizer had a significant advantage in term of P availability under maize/peanut intercropping system. Chemical regulation with P fertilization enhanced P uptake, thereby bringing significant advantage of maize/peanut intercropping system.