Passive Microwave Study of Salt Affected Agricultural Soil
Abstract
Salt affected agricultural soil from superficial horizon of local profile of Alwar region with textural
composition sand=30.2%, silt=59.7% and clay=10.1% has been selected for an estimation of observable
parameter of passive microwave remote sensing. Artificially salinized and moistened soil samples with
different concentrations in part per million (ppm) of Sodium Chloride corresponding to 0 ppm to 35000
ppm soluble in conductivity water are prepared.The real and imaginary parts of dielectric constant ε’ and
ε” for artificially moistened and salinized soil with Sodium Chloride are determined at different levels
of salinization. Real and imaginary part of dielectric constant is measured by wave-guide cell method at
a single microwave frequency 9.78 GHz and at constant temperature 330C. The Fresnel reflectivity of
salinized and moistened soil is determined for different observation angles. Further, Microwave emissivity
of salinized soil is also calculated with suitable model calculations in view of passive microwave remote
sensing. Microwave emissivity decreases with both salinity and moistness. Effect of salinity on emissivity
is very small and considerable only at higher wetness of soil. In dry soils no impact of salinity observed on
emission behaviour. High dielectric contrast between emitting layer of soil and air causes more energy to
reflect back within the soil media than that of transmitted out in air. Hence, emissivity of soil decreases
as salinity increases.
How to cite this article: Gupta VK. Passive Microwave study of salt affected agricultural Soil. J Adv Res Alt Energ Env Eco 2018;
5(1&2): 37-40.
References
2. Kolarkar A S, Dhir R P and Singh N “Characteristics and morphogenesis of salt-affected soils in south-eastern arid Rajasthan” Journal of Indian Society of Remote Sensing 8 (1) (1980) 31-34.
3. Jackson T J and O’Nell P E “Salinity effects on the microwave emission of soils,” J IEEE Trans. Geosci. Remote Sensing GE-25(1987) 214–220.
4. Sreenivas K, Venkataratnam L and Narasimaha Rao P V “Dielectric properties of salt- affected soils” Int J Remote Sensing 16(4) (1995) 641-649.
5. Yadav J S and Gandhi J M “Simple microwave technique for measuring the dielectric parameters of solids and their powders” Indian J Pure Appl Phys 30(1992) 427–432.
6. Peake W H, “Interaction of electromagnetic waves with some natural surfaces” IRE Trans on Antennas and propog AP-7 (5) (1959) 2582- 2590.
7. Kong J. A., Electromagnetic Wave Theory, 2nd edn. Wiley-Interscience, New York. (1990).
