Accurate estimates of the quantity and rate of soil nitrogen supply (SNS) are essential to increase soil and farm N use efficiencies, in particular for soils high in organic matter. The objective of this work was to enhance the empirical understanding of the SNS of dairy grasslands on peat soils, using soil properties and weather variables. Data were collected from studies on herbage N uptake carried out between 1992 and 2017 in the western peat district of the Netherlands. For the period between March to mid October, SNS was estimated from the sum of mean growing season daily temperatures, soil organic matter (SOM) and applied calcium ammonium nitrate (CAN) N with a residual standard error of 25–27 kg ha⁻¹. Each °C growing season temperature sum affected SNS by 78–90 g ha⁻¹ and each g SOM per 100 g dry soil affected SNS by 3.6–3.9 kg ha⁻¹, respectively. SNS was equally estimated for conditions with and without CAN fertilisation. Validation with data from independent field trials showed similar impacts of SOM and growing season temperature sum on SNS. The error of prediction of the presented models, however, was still too large for direct on-farm application and led to underestimations for a specific site. Nevertheless, the obtained models allow for an increased understanding of soil and farm N balances. The models can therefore be used for improved temporal and spatial SNS-adapted farming practice advice, which can potentially lead to reduced soil and farm N surpluses.

中文翻译：

---

通过度日和土壤有机质含量估算的泥炭草地土壤氮素供应

准确估算土壤氮供应量（SNS）的数量和速率对于提高土壤和农场的氮利用效率至关重要，特别是对于有机质含量高的土壤。这项工作的目的是利用土壤性质和天气变量来增强对泥炭土壤上的奶牛草原SNS的经验认识。数据收集自1992年至2017年之间在荷兰西部泥炭区进行的牧草对氮的吸收研究。在3月至10月中旬期间，SNS是根据平均生长季节每日温度，土壤有机质（SOM）和施用的硝酸钙铵（CAN）N的总和估算的，其标准误差为25–27 kg ha ^-1。每个°C的生长季节温度总和对SNS的影响为78–90 g ha ^-1每100 g干燥土壤中的每g SOM对SNS的影响分别为3.6–3.9 kg ha ^-1。对于有或没有CAN施肥的条件，均对SNS进行了均等估计。来自独立现场试验的数据验证显示，SOM和生长期温度总和对SNS具有相似的影响。但是，对于直接在农场上应用，所提出模型的预测误差仍然太大，导致对特定地点的估计不足。尽管如此，获得的模型仍使人们对土壤和农场的氮平衡有了更多的了解。因此，这些模型可用于改进适应SNS的时间和空间的农业实践建议，这有可能导致减少土壤和农场的氮过剩。