Serrano João, Shahidian Shakib, Marques da Silva José, Paniágua Luís L, Rebollo Francisco J, Moral Francisco J
MED-Mediterranean Institute for Agriculture, Environment and Development and CHANGE-Global Change and Sustainability Institute, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal.
Departamento de Ingeniería del Medio Agronómico y Forestal, Escuela de Ingenierías Agrarias, Universidad de Extremadura, Avenida Adolfo Suárez, S/N, 06007 Badajoz, Spain.
Sensors (Basel). 2024 Mar 1;24(5):1623. doi: 10.3390/s24051623.
Precision agriculture (PA) intends to validate technological tools that capture soil and crop spatial variability, which constitute the basis for the establishment of differentiated management zones (MZs). Soil apparent electrical conductivity (EC) sensors are commonly used to survey soil spatial variability. It is essential for surveys to have temporal stability to ensure correct medium- and long-term decisions. The aim of this study was to assess the temporal stability of MZ patterns using different types of EC sensors, namely an EC contact-type sensor (Veris 2000 XA, Veris Technologies, Salina, KS, USA) and an electromagnetic induction sensor (EM-38, Geonics Ltd., Mississauga, ON, Canada). These sensors were used in four fields of dryland pastures in the Alentejo region of Portugal. The first survey was carried out in October 2018, and the second was carried out in September 2020. Data processing involved synchronizing the geographic coordinates obtained using the two types of sensors in each location and establishing MZs based on a geostatistical analysis of elevation and EC data. Although the basic technologies have different principles (contact versus non-contact sensors), the surveys were carried out at different soil moisture conditions and were temporarily separated (about 2 years); the EC measurements showed statistically significant correlations in all experimental fields (correlation coefficients between 0.449 and 0.618), which were reflected in the spatially stable patterns of the MZ maps (averaging 52% of the total area across the four experimental fields). These results provide perspectives for future developments, which will need to occur in the creation of algorithms that allow the spatial variability and temporal stability of EC to be validated through smart soil sampling and analysis to generate recommendations for sustained soil amendment or fertilization.
精准农业旨在验证能够捕捉土壤和作物空间变异性的技术工具，这些变异性构成了建立差异化管理区（MZs）的基础。土壤表观电导率（EC）传感器通常用于调查土壤空间变异性。对于调查而言，具备时间稳定性至关重要，以确保做出正确的中长期决策。本研究的目的是使用不同类型的EC传感器评估MZ模式的时间稳定性，即EC接触式传感器（Veris 2000 XA，Veris Technologies，美国堪萨斯州萨利纳）和电磁感应传感器（EM - 38，Geonics Ltd.，加拿大安大略省密西沙加）。这些传感器被用于葡萄牙阿连特茹地区四个旱地牧场。第一次调查于2018年10月进行，第二次于2020年9月进行。数据处理包括在每个位置同步使用两种类型传感器获得的地理坐标，并基于海拔和EC数据的地统计分析建立MZ。尽管基本技术原理不同（接触式与非接触式传感器），调查是在不同土壤湿度条件下进行的，且时间上相隔约两年；EC测量结果在所有试验田均显示出统计学上的显著相关性（相关系数在0.449至0.618之间），这反映在MZ地图的空间稳定模式中（四个试验田总面积平均为52%）。这些结果为未来发展提供了前景，未来需要开发算法，通过智能土壤采样和分析来验证EC的空间变异性和时间稳定性，从而生成持续土壤改良或施肥的建议。
