Global Journal of Science Frontier Research, D: Agriculture and Veterinary, Volume 23 Issue 1

The S shaped SSI with depth (Left). Available water as a response to the combine stress (right). µ = ( | ) = 1/ ω c (5) Where: µ: first order derivative of PSI= ƒ(SSI). dSSI: change in soil stress index. dPSI: change in plant stress index.1/ ωc: the compensation factor. A fully-developed meniscus in a cylindrical tube showing the equality between the upward pull of surface tension and the downward pull of the suction in the water from which the relation ΔP=2γ/r can be derived (Bazaraa, 2015). 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1 6 11 16 21 26 31 36 41 46 SSI Depth (cm) EC= 3.12+ Time= 73 days Uncompensated fully Compensated parially Comp. -100.00 -50.00 0.00 50.00 100.00 1 21 41 61 81 101 121 141 Time (day) Available water (mm) Available water (mm) EC=3.12 Available water (mm) EC=4.82 Available water (mm) EC=5.12 © 2023 Global Journals 1 Year 2023 34 Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( ) Figure 3: Figure 4: D The Modified Richard’s Equation for Assessing the Impact of Drought and Salinity in Arid and Semi-Arid Zones. Part Two: A Soil Hydraulic Capacitance