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首页> 美国卫生研究院文献>The Scientific World Journal >Nitrogen Fertilizer Rate and Crop Management Effects on Nitrate Leaching from an Agricultural Field in Central Pennsylvania
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Nitrogen Fertilizer Rate and Crop Management Effects on Nitrate Leaching from an Agricultural Field in Central Pennsylvania

机译：宾夕法尼亚中部农田氮肥用量和作物管理对硝态氮淋溶的影响

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Eighteen pan lysimeters were installed at a depth of 1.2 m in a Hagerstown silt loam soil in a corn field in central Pennsylvania in 1988. In 1995, wick lysimeters were also installed at 1.2 m depth in the same access pits. Treatments have included N fertilizer rates, use of manure, crop rotation (continuous corn, corn-soybean, alfalfa-corn), and tillage (chisel plow-disk, no-till). The leachate data were used to evaluate a number of nitrate leaching models. Some of the highlights of the 11 years of results include the following: 1) growing corn without organic N inputs at the economic optimum N rate (EON) resulted in NO3-N concentrations of 15 to 20 mg l in leachate; 2) use of manure or previous alfalfa crop as partial source of N also resulted in 15 to 20 mg l of NO3-N in leachate below corn at EON; 3) NO3-N concentration in leachate below alfalfa was approximately 4 mg l; 4) NO3-N concentration in leachate below soybeans following corn was influenced by fertilizer N rate applied to corn; 5) the mass of NO3-N leached below corn at the EON rate averaged 90 kg N ha (approx. 40% of fertilizer N applied at EON); 6) wick lysimeters collected approximately 100% of leachate vs. 40–50% collected by pan lysimeters. Coefficients of variation of the collected leachate volumes for both lysimeter types were similar; 7) tillage did not markedly affect nitrate leaching losses; 8) tested leaching models could accurately predict leachate volumes and could be calibrated to match nitrate leaching losses in calibration years, but only one model (SOILN) accurately predicted nitrate leaching losses in the majority of validation treatment years. Apparent problems with tested models: there was difficulty estimating sizes of organic N pools and their transformation rates, and the models either did not include a macropore flow component or did not handle macropore flow well.
机译：1988年，在宾夕法尼亚州中部一个玉米田的黑格斯敦淤泥质壤土中，在深度为1.2 m处安装了18个盘式溶渗仪。在1995年，在同一出入坑中，在深度为1.2 m的位置安装了灯芯测渗仪。处理措施包括氮肥用量，肥料使用，轮作（连续玉米，玉米-大豆，苜蓿-玉米）和耕作（凿犁盘，免耕）。渗滤液数据用于评估许多硝酸盐淋滤模型。 11年结果的一些亮点包括：1）以经济上最适氮率（EON）种植没有有机氮输入的玉米，导致渗滤液中NO3-N的浓度为15至20 mg l； 2）使用粪肥或以前的苜蓿作物作为氮的部分来源，也会在EON时在玉米下方的渗滤液中产生15至20 mg l的NO3-N； 3）苜蓿以下渗滤液中的NO3-N浓度约为4 mg l； 4）玉米追施氮肥对玉米以下大豆下渗滤液中NO3-N含量的影响； 5）以EON速率浸出玉米下方的NO3-N的质量平均为90 kg N ha（在EON时施用的肥料N的大约40％）； 6）灯芯测渗仪收集了大约100％的渗滤液，而平底锅测渗仪收集了40–50％。两种渗渗仪类型收集的渗滤液体积的变化系数相似； 7）耕作对硝酸盐淋失没有明显影响； 8）经过测试的浸出模型可以准确预测渗滤液量，并且可以在校准年中进行校准以匹配硝酸盐浸出损失，但是只有一种模型（SOILN）在大多数验证处理年中可以准确预测硝酸盐浸出损失。测试模型的明显问题：难以估算有机氮库的大小及其转化率，并且该模型要么不包含大孔流量成分，要么不能很好地处理大孔流量。

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