부산대학교 도서관

Highlights • Data were compiled from 212 studies in China, amounting to 1077 observations. • Leaching of NO 3 was significantly correlated with NO 3 accumulation in the soil. • Control-release fertilizer reduced 50% of NO 3 accumulation for maize than urea. • Compared to flood irrigation, sprinkler irrigation increased NO3 leaching potential driven by intensive rainfall. Abstract Application rates of fertilizers in China often exceed crop requirements, resulting in high accumulation of nitrate (NO 3) in the soil. Nitrate that has accumulated in soils is highly prone to leaching, directly threatening the quality of groundwater. A study was conducted to assess the magnitude of NO 3 accumulation and leaching in China, to identify factors controlling NO 3 accumulation and leaching, and to develop strategies that can be used to minimize NO 3 leaching. Data were compiled from 212 studies conducted in China, amounting to 1077 observations of the NO 3 content of the 0–100 cm soil profile in wheat and maize fields after harvest. Leaching of NO 3 was significantly correlated with NO 3 accumulation in the soil. NO 3 leaching increased with 0.058 and 0.34 kg NO 3 -N ha−1 per season for wheat and maize, respectively, for every 1 kg ha-1 increase in NO 3 -N accumulation in 0–100 cm. This mainly related to lower precipitation during the wheat season and intensive rainfall in the maize season. Accumulation of NO 3 in maize systems was 50% lower than for wheat when fertilized at the same rate, due to differences in rainfall between seasons. Soil NO 3 accumulation was higher in heavy textured soils than in freely draining lighter textured soils, as most of NO 3 leached out of 0–100 cm soil in lighter textured soils. Compared to flood irrigation, sprinkler irrigation increased NO 3 accumulation by 17% and 152% for wheat and maize, respectively, due to lower irrigation and leaching rate. The level of nitrate accumulation in Chinese arable soils has become a significant hazard to drinking water, so good agricultural management is essential. Soil NO 3 accumulation and leaching in China can be reduced by source and process control, such as reducing fertilizer application, using slow or controlled release forms of fertilizers, and regulating irrigation. [ABSTRACT FROM AUTHOR]