Mean potential nitrate discharge hazard (federal method)

The mean potential risk of nitrate discharge is used to assess the mean risk of nitrate leaching from the root space of vegetation by leaching soil water. The location of the assessment is the lower bound of the rooted soil layer. The ratio of leachate rate and usable field capacity in the effective root space (nFKWe) first provides the exchange frequency of the plant-available soil water. This is classified in 5 stages (very low – very high) and gives the pNAG. The characteristic value of the potential risk of nitrate discharge is not suitable for deriving quantitative statements, as use-dependent influencing variables (e.g. crop type, quantities of nitrogen added and removed, autumn nitrate content in the soil) are not taken into account. The calculation of the potential nitrate discharge risk according to the federal method is based on the evaluation method 5.3 (AG Boden, 2000b). Further information can be found here: https://geo.brandenburg.de/karten/htdocs/21042020_Sickerwasserrate.pdf本研究以硝酸盐淋失潜在平均风险为指标，评估土壤水淋洗作用下植被根域的硝酸盐淋失平均风险。评估点位设置于根系土层下界。有效根域内的淋滤液速率与有效田间持水量之比（nFKWe），可表征植物有效土壤水的交换频率。该交换频率被划分为5个等级（极低至极高），并据此得到pNAG指标。由于该方法未纳入与施用相关的影响因子（如作物类型、氮素输入与输出量、土壤秋季硝酸盐含量），因此硝酸盐淋失潜在风险特征值不适用于推导定量结论。基于联邦方法的硝酸盐淋失潜在风险计算，依据《AG Boden, 2000b》中的5.3号评价方法开展。 更多详细信息可参阅以下链接： https://geo.brandenburg.de/karten/htdocs/21042020_Sickerwasserrate.pdf