Improving Quality Agricultural Practices in Tropical Environments through Integrated Geophysical Methods

Abstract

Often, much attention is paid to things that do not majorly sustain life while the main pre requisite to living is usually left unattended to. Geoscience has been a tool used in solving the Earth's challenges both directly and indirectly. For instance, mining processes as well as hydrocarbon exploration has been aided extensively by the application of Geoscience, whereas Geophysics as a branch of Geoscience, which has proven worthwhile with so much importance in solving societal major need - Agriculture, is not gaining much attention.For agricultural application of geophysical methods, the three of all methods predominantly used are Electrical resistivity, Electromagnetic induction, and Ground Penetrating Radar (GPR). All these three methods are active, requiring artificial application of energy.Electrical resistivity method measures the electrical resistance for a bulk volume of soil which lies beneath the surface. This method basically reveals the subsurface electric field produced by the artificial application of electric current into the ground. An electromagnetic induction method measures the electrical conductivity for a bulk volume of soil directly beneath the surface. An instrument called ground conductivity meter is commonly employed for shallow electromagnetic induction investigations. With the Ground-penetrating radar method, an electromagnetic radio energy pulse is directed into the subsurface, followed by measurement of the elapsed time taken by the radar signal as it travels downward from the transmitting antenna, partially reflects off a buried feature, and eventually when it returns to the surface as it is picked up by a receiver. Past research indicates a wide range of indispensable uses for these three major geophysical methods employed in agriculture. Starting from soil water content monitoring using apparent soil electrical conductivity (ECa) measurements and Soil salinity assessment obtained with electrical resistivity and electromagnetic induction methods, followed by the use of GPR for updating and improving soil survey maps. These are used to evaluate soil property spatial variation.Agricultural geophysical measurements often tend to exhibit substantial variability by measuring soil electrical conductivity, soil dielectric constant (Water Content), spatial, horizontal and vertical changes. The Soil Water Content (SWC) controls important physical, chemical and biological processes such as plant growth, solute transport, rainfall, runoff, erosion, and ultimately pedogenesis. An understanding of the spatial and temporal variability in the soil properties (precision farming) using Geophysical methods will enhance the agricultural produce as well as soil management.Agricultural geophysics is the simplest and the most rapid method of identifying the nature of soil