The Effect Of Urea Application On Cool Season Mixed Turf And Nitrogen Fate

With rapid development of the economy and quick improvement of people's livelihood, the turf area of all kinds has increased rapidly in China, bringing to people beautiful environment. Fertilizatin is one of the three primary cultural practices for managing a healthy turf. Urea is the main nitrogen carrier of turf fertilizers. When nitrogen fertilizer is applied into turf ecosystem, some parts would be absorbed by plant, some parts would remain in the soil, and the rest would be emigrated out of turf ecosystem. Studies should that 10% of the total nitrogen would go to the surface water or underground water in nitric nitrogen form. Environmental pollution caused by fertilization has been receiving serious concern in many developed countries, while there is still little research on this field in China.This research was aimed to study the effects of urea application to cool season turf and the fate of nitrogen from urea in Beijing area. Attention was gived to the pollution caused by urea application. In the experimental design, urea application takes three levels: low nitrogen, medium nitrogen, and high nitrogen.The turf quality indicator such as color and growth rate was measured. Forms and content of nitrogen was analyzied both in the plant and the soil. Importance was given to the nitrate leaching in underground water .The result showed that for a good appearance and healthy turf ,the proper annual urea application rate was about 62.5g/m2. Lower than this rate may have adverse impact on turf growth.Higher than this rate may cause pollution risk. As for the proper urea application season, the experiment showed that autumn was better than spring, because in spring the nitric nitrogen leaching loss was much more than in autumn. There was no positive relationship between the urea employment level and the content of total nitrogen, ammonium nitrogen and nitric nitrogen content in soil.