Integrated EMI–GPR surveys can support precision agriculture by monitoring and evaluating the effects of land uses and agricultural management
Expanding of agricultural areas, coupled with the effects of climate change are expected to put accelerating pressure such as more demand, degradation and variable precipitation etc., on land and water resources. To address this challenge, precision agriculture has become a key strategy for increasing agricultural productivity with minimum input and environmental damages. In order to facilitate the sustainable management of land and water resources, knowledge of spatiotemporal variability of relevant soil properties is needed. This demands methods for obtaining data at different scales rapidly and cost-effectively, enabling the evaluation of soil-related properties under variable land and crop management conditions. Based on my collected data thus far, the effects of different land use and agronomic practices on soil properties and soil hydrology can be assessed, adjusted and optimized in supporting precision agriculture.
Land use changes and agricultural activities alter soil properties and soil hydrology which can directly affect the sustainability of agriculture, as well as the adjacent natural systems. Continuous monitoring of an assortment of relevant soil properties is thus necessary in order to maintain land and water productivity and quality, especially under projected changing climatic conditions. However, mapping and monitoring of soil properties using traditional methods is expensive, labor-intensive, and time-consuming and provides point information only. Thus, rapid-response management activities such as real-time decisions on optimum irrigation and timing are difficult. A potential way to acquire information at field-scale is by non-invasive measuring of easily recordable physical variables, such as apparent electrical conductivity (ECa) using electromagnetic induction (EMI) that correlates with relevant soil properties. The ground penetrating radar (GPR) method for estimating SWC using radar wave velocity (RWv) under variable field conditions has been carried out successfully. The depth sensitivity of GPR is less complex than EMI, representing a function of SWC and wave frequency. Still, the application of GPR is time-consuming in comparison to EMI, which commonly limits the survey area or the monitoring frequency. An integrated EMI–GPR approach however, could provide the opportunity to calibrate the ECa and allows the interpretation of large scale EMI data towards the variability of desired physical and hydraulic properties of soils.
The main goal of this research is to generate high-resolution maps of key soil properties in order to assess the effects of different land uses and agronomic practices on soil hydrology in supporting precision agriculture.