Studies on the Effect of Fertilizer-N upon Winter Wheat by Using Stable Isotope ~(15)N Stable Isotope ~(15)N

The law of absorption and utilization of fertilizer-N in winter wheat and the effect of applying fertilizer in different stages of growth upon the productionand the production constitute are discovered by using stable isotope ~(15)N withZhT-02 mass spectrometer. According to these studies, a scientific basis is provi-ded for rational application of fertilizer to stabilize the increase of production.