应用~(15)N 研究了中低产田小麦对氮肥的吸收和分配。结果表明:小麦出苗—拔节期,其根茎叶吸收 N 量随施 N 量的增加而下降,茎叶的氮肥利用率大于根系;小麦拔节—成熟期,在亩施5—15kgN 时,其利用率呈直线上升;施 N 量增至20kg以上,利用率明显下降,根茎叶的氮肥利用率明显低于籽粒。亩施15kgN 时,籽粒蛋白质含量增加。 Applying ~ (15) N to study the absorption and distribution of nitrogen fertilizer in middle and low yielding wheat. The results showed that the N uptake of roots and leaves decreased with the increase of N application rate at the emergence and jointing stages of wheat and the nitrogen utilization efficiency of stems and leaves was greater than that of the roots. In wheat jointing and maturing stage, Increased linearly; N application increased to more than 20kg, the utilization rate decreased significantly, nitrogen utilization efficiency of roots and leaves was significantly lower than the grain. Kernel Shi 15kgN, grain protein content increased.