Abstract The use of moisture readings by the indirect method has been increasing in recent years, such as the use of a frequency domain reflectometry capacitance (FDR) technology, but the use of this equipment requires a calibration for the soil. Usually these equipments are calibrated by soil layers, but the calibration of an FDR sensor by different soil tillage has never been performed. Therefore, this study aimed to: i) calibrate a frequency domain reflectometry capacitance probe (FDR) for a Ultisol Udult; ii) evaluate the calibration by Bland-Altman’s methodology; iii) calibrate the equipment for the same soil by applying four different soil tillage systems (conventional tillage, minimum tillage, minimum tillage with deep subsoiling, and no-tillage); iv) evaluate whether calibration separated by soil tillage is more effective than without separation. The experiment was carried out using split-pilot design on the premises of the Santa Fe plant, municipality of Ibitinga-SP-Brazil. Probe calibration reached up to one meter deep and generated four regression curves, one for each soil tillage system with the soil bulk density and macroporosity affecting the Diviner 2000 equipment calibration. Manufacturer’s soil calibration proved inadequate based on Bland-Altman’s methodology. It was used soil tillage systems as separation factor to calibrate the equipment, which increased the determination coefficient in 16 % in relation to soil calibration. Soil tillage, by modifying the structure of soil physical attributes, also affected the calibration of the Diviner 2000 equipment, proving that in an area where different soil tillages occurs, one calibration must take place for each soil tillage.

中文翻译：

---

通过土壤耕作用甘蔗种植的 Ultisol Udult 的电容探头校准

摘要 近年来，越来越多地使用间接方法读取水分，例如使用频域反射电容 (FDR) 技术，但使用这种设备需要对土壤进行校准。通常这些设备是按土层校准的，但从未进行过不同土壤耕作对FDR传感器的校准。因此，本研究旨在： i) 校准 Ultisol Udult 的频域反射计电容探头 (FDR)；ii) 通过 Bland-Altman 方法评估校准；iii) 通过应用四种不同的土壤耕作系统（常规耕作、最少耕作、深松土最少耕作和免耕）来校准同一土壤的设备；iv) 评估土壤耕作分离的校准是否比不分离更有效。该实验是在巴西 Ibitinga-SP-Brazil 市 Santa Fe 工厂内使用分体试验设计进行的。探头校准深度可达一米，并生成四条回归曲线，每个土壤耕作系统一条曲线，土壤容重和大孔隙率影响 Diviner 2000 设备校准。根据 Bland-Altman 的方法，制造商的土壤校准证明是不充分的。使用土壤耕作系统作为分离因子对设备进行校准，与土壤校准相比，测定系数提高了16%。土壤耕作，通过修改土壤物理属性的结构，也影响了 Diviner 2000 设备的校准，