通过对我国近10年382组农田N素淋失数据进行统计分析,发现水田的NO3^--N淋失量与土壤体积质量、有机质、全N(TN)、黏粒含量百分比显著负相关,与施N量、灌水量显著正相关;旱地中NO3^--N淋失量与全P(TP)、粉粒含量百分比、土层深度显著负相关,与土壤中TN含量、砂粒百分比含量、施N量、降雨量、灌溉水量显著正相关。水田中总N表观淋失率平均值为2.19%,95%的置信区间为1.56%~2.82%;旱地中总N表观淋失率平均值为4.35%,95%的置信区间2.88%~5.82%。根据2008年中国统计年鉴计算出2007年我国总N淋失量达到0.644 Tg,约占我国总施N量的2.80%。
Statistical analysis of 382 data of nitrogen leaching in farmland of China was conducted to identify the major influencing factors.The results showed that nitrate leaching was closely related to total nitrogen leaching.The amount of nitrate leaching in paddy field was significantly negatively correlated with soil bulk density,organic matter content,TN,soil clay percentage,and positively correlated to nitrogen application rate and irrigation.The amount of nitrate leaching in upland was significantly negatively correlated with soil total phosphorus content,sand percentage,nitrogen application,rainfall,irrigation,and positively correlated with TN,silt percentage and soil depth.The average net rate of total nitrogen leaching was 2.19%(95% confidence interval of 1.56% ~ 2.82%) in paddy field and 4.35%(95% confidence interval of 2.88% ~ 5.82%) in upland.According to nitrogen fertilizer consumption data in China Statistical Yearbook 2007,it was estimated that total nitrogen leaching was up to 0.644 Tg,accounting for 2.80% of China's total nitrogen application.