Effects of NBPT urease inhibitor on ammonia volatilization in paddy fields with wheat straw application Effect of the flood on the bacterial community of bacteriaplankton in Daling River Concentration change and migration characteristics of nitrogen in the paddy field of Ningxia Yellow River Irrigation Area Leaching characteristics of nitrogen and phosphorus in treated paddy fields with chicken manure Surface Water Contamination Potential of Seven Golf Courses in Beijing Ecosystem services analyses and valuation of China terrestrial surface water system Soil phosphorous accumulation in long-term P fertilization paddy field and its environmental effects