Effects of ethephon and phosphate fertilizer on N absorption and intercropped advantages of maize and peanut intercropping system

ObjectivesIn maize and peanut intercropping system, foliar spray of ethephon will reduce the plant height of maize, enhance the yield of peanut and the intercropping system. In this paper, the effect of phospharous application on the goodness of chemical regulation was further studied.

MethodsA field experiment was conducted from 2012 to 2013 in the farm of Henan University of Science and Technology. The experiment included 4 planting models:monocultured maize, monocultured peanut, maize and peanut intercropping with ethephon foliar spray, and maize and peanut intercropping without ethephon foliar spray, with or without the application of P fertilizer. The N content, accumulation and distribution in different organs of intercropped maize and peanut were determined, and the yield were investigated.

ResultsCompared with monoculture, maize and peanut intercropping significantly enhanced the N content in stems, leaves and seeds of intercropped maize and peanut, increased the N accumulation of intercropped maize, and promoted N allocation to grain of intercropped maize, but reduced N accumulation and allocation to nuts of intercropped peanut. N absorption of maize and peanut intercropping system was higher than that of monocultured maize or peanut, N intercropped advantage was N 26.88-42.21 kg/hm². Compared with no ethephon foliar spray, spraying ethephon decreased N competition ratio of maize to peanut, reduced the N content and accumulation in stems, leaves and seeds of intercropped maize, enhanced N allocation in grain of intercropped maize, and increased the N content and accumulation in stems, leaves and nuts of intercropped peanut, N distribution to nuts of intercropped peanut was promoted. N absorption of intercropped peanut and N absorption intercropped advantage were enhanced by 23.67%-49.54% (P < 0.05) and 4.95%-54.65%, respectively. Compared with no P fertilizer application, P fertilizer promoted the absorption of N in maize and peanut in the intercropping system with spraying ethephon to maize, with the N absorption enhanced by 19.49%-27.71% and 34.26%-43.24% (P < 0.05), respectively, and intercropping advantage in N absorption was increased by 69.97%-162.57% (P < 0.05).

ConclusionsFoliar spraying ethephon could decrease N competition ratio of maize to peanut, promote the N absorption of maize and peanut intercropping system and N distribution to seed, improve N absorption intercropping advantage, and promote the efficient utilization of nitrogen. P fertilizer application further strengthen the good effects of spraying ethephon.