In this study, site-specific N balances were calculated for a 13.1 ha heterogeneous field. Yields and N uptake as input data for N balances were determined with data from a combine harvester, reflectance measurements from satellites and tractor-mounted sensors. The correlations between the measured grain yields and yields determined by digital methods were moderate. The calculated values for the N surpluses had a wide range within the field. Nitrogen surpluses were calculated from − 76.4 to 91.3 kg ha⁻¹, with a mean of 24.0 kg ha⁻¹. The use of different data sources and data collection methods had an impact on the results of N balancing. The results show the need for further optimization and improvement in the accuracy of digital methods. The factors influencing N uptake and N surplus were determined by analysing soil properties of georeferenced soil samples. Soil properties showed considerable spatial variation within the field. Soil organic carbon correlated very strongly with total nitrogen content (r = 0.97), moderately with N uptake (sensor, r = 0.60) and negatively with N surplus (satellite, r = − 0.46; sensor, r = − 0.56; harvester, r = − 0.60). Nitrate content was analysed in soil cores (0 to 9 m) taken in different yield zones, and compared with the calculated N surplus; there was a strong correlation between the measured nitrate content and calculated N surplus (r = 0.82). Site-specific N balancing can contribute to a more precise identification of the risk of nitrate losses and the development of targeted nitrate reduction strategies.

在这项研究中，针对一个13.1公顷的非均质田地计算了特定地点的氮平衡。使用联合收割机的数据，卫星的反射率测量值和安装在拖拉机上的传感器确定了氮平衡的输入数据，即产量和氮吸收量。测得的谷物单产与通过数字方法确定的单产之间的相关性中等。N个盈余的计算值在该字段中具有很大的范围。计算出的氮剩余量为− 76.4至91.3 kg ha ^-1，平均为24.0 kg ha ^-1。使用不同的数据源和数据收集方法会对氮平衡的结果产生影响。结果表明需要进一步优化和改进数字方法的准确性。通过分析地质参考土壤样品的土壤特性，确定影响氮素吸收和氮素过量的因素。土壤特性表明田间空间变化很大。土壤有机碳与总氮含量高度相关（r  = 0.97），与氮吸收呈中等强度（传感器，r  = 0.60），与氮过量呈负相关（卫星，r = − 0.46；传感器，r = − 0.56；收割机，r= − 0.60）。分析了在不同产量区的土壤核心（0至9 m）中的硝酸盐含量，并与计算出的氮过剩进行了比较；测得的硝酸盐含量与计算得出的氮过剩之间有很强的相关性（r  = 0.82）。特定地点的氮平衡可有助于更准确地确定硝酸盐损失的风险，并制定有针对性的硝酸盐还原策略。