以两年生红富士/平邑甜茶为试材,采用田间小区试验及15N同位素标记示踪法,研究了低氮(50千克每公顷)和中氮(100千克每公顷)条件下分别种植白三叶、黑麦草和鼠茅草3种牧草对苹果幼树生长及15N-尿素吸收、利用的影响。结果表明,春梢停长期,与单作苹果相比,种植牧草后苹果植株生物量、吸氮量及15N肥料利用率显著降低,这在低氮处理下尤为明显;而 Using two-year-old Red Fuji and Pingyi sweet tea as test materials, field trials and 15N isotope labeling tracer were used to study the effects of low nitrogen (50 kg ha -1) and medium nitrogen (100 kg ha -1) Effects of Three Forages of Leaf, Ryegrass and Rattan on Growth and 15N-Urea Absorption and Utilization of Young Apple Trees. The results showed that compared with single-cropping apples, the plant biomass, N uptake and 15N fertilizer use efficiency of apples decreased significantly after the spring shoots were stopped, especially under the low N treatment.