Nitrogen Content,Response to Nitrogen Fertilization and N₂O Emission of Soil at Tea Plantations

Nitrogen is one of the essential nutrients for tea growth?and?development.Its supply directly affects tea yield and quality.This article reviews and analyzes the current status of the nitrogen in soil at tea plantations in China, the effects of the amount, forms and ratio in NPK fertilizers of nitrogen on tea plants, as well as the N2 O emission mechanism and associated factors.Chemical nitrogen fertilizer has a significant effect on the total nitrogen content in the soil at tea plantations.Appropriate application of nitrogen could remarkably improve tea yield and nutrition quality.But, excessive applications, either too high or too low a nitrogen level, could stunt the growth.Nitrogen fertilizers, such as ammonium and ammonium-nitrogen, normally benefit the tea quality.It is generally considered adequate for tea fertilization at the rate of N 200.0-350kg·hm-2, and a N∶P∶K ratio of 2∶1∶1.Since nitrogen fertilization can significantly increase N2 O emission, its application directly affects the air quality.Consequently, in order to maximize nitrogen fertilization efficiency while minimize air pollution to the environment, appropriate managerial strategies must be implemented.