中文摘要：

通过田间试验探讨了Al（N，210kg·hm^-2）、A2（N，270kg·hm^-2）、A3（N，330kg·hm^-2）3种施氮水平和距窄行玉米B1（0cm）、B2（15cm）、B3（30cm）、B4（45cm）4种施肥距离对玉米一大豆套作体系氮素吸收利用效率的影响。结果表明，与习惯施氮（A3）相比，减量施氮（A1、A2）提高了大豆R2、R5期单株根瘤数、根瘤干重和根瘤固氮潜力，以距玉米15cm处施肥的根瘤固氮能力较强；玉米、大豆的籽粒产量、地下部植株氮素吸收量和氮肥利用率随施氮量的增加呈先增加再降低的趋势，以A2处理的最高；施肥距离过大和过小均不利玉米、大豆产量的提高和氮素的吸收利用，以距玉米15～30cm处施肥效果最佳；减量施氮18％（A2）时，B2、B3处理相对常规穴施（B1）处理，玉米、大百及玉米一大豆系统的籽粒产量、植株氮素吸收量、氮肥利用率和土壤总氮含量均显著提高，土壤氮素贡献率显著降低。

英文摘要：

Abstract ： To investigate the effect of N application methods on N uptake and utilization efficiency in the maizesoybean relay strip intercropping system, a field experiment was conducted with three N application rates （N, 210, 270 and 310kg · hm^-2, which is considered as three N treatments, and denoted as A1, A2 and A3, respectively） and four fertilization applied distances （the distance between the fertilization dot and the narrow row corn of four treatments were 0,15,30,45cm, denoted as B1, B2, B3 and B4, respectively）. The results showed that at the treatments of A1 and A2, the number, dry weight and the potential nitrogen fixation of nodules for each plant were higher than those of conventional N application rate （ A3 ） at the stages of R2 and R5. At the same time, the nodules nitrogenase ability of treatment B2 was more than those of other treatments. With the increasing of nitrogen application rates, the grain yield, N uptake and N use efficiency of maize and soybean increased, then dropped. The maximum values of the indices occurred at the treatment of A2. The application distance of fertilization significantly affected the yield, nutrient uptake and utilization of maize and soybean. The fertilization effect was optimal when the distance was between 15 and 30 cm. As the amount of N fertilizer decreased by 18% （A2） , the grain yield of maize, soybean and the intercropping system, N uptake of plants, N utilization efficiency and the total nitrogen content of soil improved significantly with B2 and B3 treatments, comparing with the conventional fertilization of B1 treatment, N contribution rate of soil reduced significantly.