Abstract: 【Objective】 This study clarified the nitrogen absorption and utilization characteristics in maize-peanut intercropping by studying the nitrogen concentration, nitrogen uptake, nodulation of peanut and nitrogen distribution under different configuration, which may provide a basis for regional screening and application of N efficient model of maize-peanut intercropping. 【Method】 A field study with 10 treatments was conducted in National Agricultural Experimental Station for Agricultural Environment in Fuxin in 2015 and 2016, which including four cropping systems, sole maize (M), sole peanut (P), intercropping system of 2 rows maize and 4 rows peanut (M2P4), intercropping system of 4 rows maize and 4 rows peanut (M4P4). Each maize treatment including three maize densities (6, 9 and 12 plants/m2). The characteristics and advantages of nitrogen uptake and utilization in maize-peanut intercropping system with different configurations (row proportion and maize density) were analyzed. 【Result】 Compared with monocropping, the change of N concentration in maize and peanut plants was not significant, the N yield of maize and peanut in intercropping was lower than that in monocropping due to the different proportion of land occupy, and was consistent with intercropping biomass performance. Maize-peanut intercropping significantly increased the system nitrogen uptake (N uptake equivalent ratio NER>1), which was mainly due to the nutrient absorption advantage of maize (pNER_m was 0.63~0.80). The NER was increased as the row and density of maize increasing. The nitrogen uptake in M4P4 pattern (NER 1.06~1.22) was significantly higher than that in M2P4 pattern (NER 1.0~1.06). In maize-peanut intercropping system, Maize was more competitive than peanuts (A_mp>0), and the competitive ability to absorb nitrogen was also stronger (CR_mp>1), M4P4 pattern and maize densification can enhance maize competition for nitrogen, increase the advantage of nitrogen uptake (△NU>0) and the contribution of intercropping nutrients to yield. Intercropping with maize could promote nodule formation of peanut. The number of nodule, weight of nodule per plant and weight per nodule of peanut under M4P4 pattern were higher than those under M2P4 pattern, and medium and low density treatments were better for nodulation. The soil available nitrogen content (Nmin) in the intercropping system was higher in the peanut strip than in the maize strip, and the Nmin in the sole peanut strip was higher than that in the intercropped peanut strip, while the Nmin in the sole maize strip was lower than that in the intercropped maize strip. 【Conclusion】 Maize-peanut intercropping could significantly improve the nitrogen uptake and utilization in the system, and maize contributed more to the system nitrogen uptake. Moderate increase of maize row ratio and density was beneficial to increase the nitrogen uptake equivalent ratio, enhance maize competition for nitrogen nutrition, and the contribution of intercropping nutrients to yield. In this study, M4P4-6 and M4P4-8 were the better pattern for maize-peanut intercropping, and the contribution rate of nitrogen uptake and utilization to the yield of the system could reach 18%. The promotion of maize/peanut intercropping on dry matter and peanut biological nitrogen fixation, as well as the competitive ability of maize to absorb nitrogen, were the important reasons for the advantages of maize/peanut intercropping in nitrogen utilization.

Key words: Intercropping, Configuration, Maize, Peanut, Nitrogen uptake