Modeling nitrate leaching on a cropped Andosol
Modeling nitrate leaching on a cropped Andosol
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DOI：
10.1007/s10705-009-9247-x
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发表时间：
2009-09-01
影响因子：
3.1
通讯作者：
Kohyama, K.
中科院分区：
文献类型：
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作者：
Endo, A.;Mishima, S.;Kohyama, K.
利用气象特征、三组分硝化和/或反硝化链（NH（4）-> NO（3）-> N（2））和耕作制度，建立了基于多用途求解器的土壤硝态氮迁移模型，以评价耕作后土壤硝态氮的淋溶行为。通过将模型计算结果与毛细管蒸渗仪试验结果进行比较，验证了模型的有效性。将累积水通量和累积硝态氮（NO3-N）通量的实测值与模拟值进行比较，并通过均方根误差（RMSE）和t值检验统计量验证了模型的准确性。使用该模型的计算结果是准确的，尽管参数的数量很少（例如。G.脱氮率、固定化率等）采用简单的机理子模型。为了直观和定性地了解土壤层位中NO（3）-N浓度的行为，我们使用了一个耕作的土壤孔隙水中NO（3）-N浓度的彩色等值线。从验证结果和等值线结果来看，当（1）农田具有高渗透性和低吸附能力时，硝酸盐的淋溶风险可能会增加，当（2）施用氮肥后不久就下大雨时。RMSE和t检验的结果表明，FlexPDE模型与实测资料的关系比Hydrus-1D模型更接近。
The nitrate transfer model in Andosol using the multipurpose solver was developed using meteorological characteristics, three-species nitrification and/or denitrification chain (NH(4) -> NO(3) -> N(2)), and a cropping system to evaluate the behavior of nitrate leaching from a cropped Andosol. Its validity was then tested by comparing results calculated by proposed model with results from a capillary lysimeter experiment. The measured values of cumulative water flux and cumulative nitrate nitrogen (NO(3)-N) flux were compared with those of simulated values, and the accuracy of proposed model was verified by using test statistics of the root mean square error (RMSE) and t-value. The calculated results using the proposed model were accurate despite the small numbers of parameters (e. g. denitrification rate, immobilization rate etc.) and simple mechanistic sub-models were adopted. To understand the behavior of NO(3)-N concentration visually and qualitatively in the soil horizon, we used colored isopleths of NO(3)-N concentration in pore water at a cropped Andosol. From the validated results and isopleths results, the leaching risk of nitrate is likely to increase when (1) the agricultural land has high permeability and low capability of adsorption of nitrate, and when (2) heavy rains fall soon after application of nitrogen fertilizer. The results of RMSE and t-test, it was demonstrated that relationship between FlexPDE and observed data is in more agreement than the Hydrus-1D model.