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

The combined abiotic stresses of drought and salinity make the main components of the agro-ecosystem, plant and soil, start their response functions on (0/1) to save the life on planet earth. The soil water becomes less or even unavailable for plant machinery systems in spite their cumulative actions whether they are either additive or multiplicative. The wheat’s hydraulic signal could roll leaves in order to reduce the leaf area index and net radiation (Nar et al., 2009) and could inhibit the root growth in the dry topsoil as a response to applied stress. Silicon, the second most abundant element in the earth’s crust, can act as plants’ first aid for healing the stressed parts to overcome the abiotic extremes (Epstein, 2009). As a response to a highly energetic soil solution, plants increase the uptake of silicon to alleviate the damaging effects of abiotic stresses. The negative interaction between silicon and sodium and the positive interaction between silicon and basic nutrients may stimulate plants to alleviate the side effects of abiotic stresses. Its deposits in roots enhance the elasticity, in tricombs enhance their function in cooling leaves and in leaves increase the water use efficiency under optimal conditions (Elsokkary, 2018) and enhance the transpiration under sub-optimal conditions. Silicon enhances the process osmoregulation which makes the suction head inside the plants’ roots to be in a higher negative potential in order to overcome the total potential of soil solution (Hegazy, 2020). Despite of the natural abiotic stresses produced by global climatic changes, the siliceous nutrition of plants is not only scientifically intriguing but also important in a world where more food will have to be wrung from a finite area of land, especially for the deficit irrigation and partial root-zone drying scenarios which will put crops under artificial stress. (Epstein, 2009 and Elkhatib et al., 2017). The aims of this research are to use the stress form of modified Richard’s equation to achieve a set of equations, AMUN_SHC. The latter is used to calculate, analyze and discuss the soil hydraulic capacitance and therefore determines the water uptake under stress conditions. Moreover, this research studies the forces control β, the stress strain relationship, and therefore the ascending of sap under the relative extreme combined stresse conditions. In the present investigation, a field experiment was carried out in Egypt as a major country in the African Sahara desert. An open field experiment was conducted at Oraby village, Maryout area, Alexandria between latitudes 30 o : 31 o degree north and between altitudes 30:32 east during the latest most drying year, 2009/2010 (Natural drought and salinity treatments (Fig. 3). Wheat grains, Sakha 94, were sown on November 27th in all field experimental plots and harvested in the first week of May. Fertilization was managed according to the recommendations of the ministry of agriculture this year. Natural drought and salinity were managed by silica fertilization. The response of wheat to silicon doses was investigated by its addition as potassium silicates and sodium silicates in three concentrations 0.0, 30.6, and 40.8 ppm. All of them were foliar sprayed at the ages of 40, 60, and 75 days from seed emergence at the early morning. The 6 treatment combinations were distributed in three salinity levels for saturated soil paste, ECe= 6.4, 9.7 and 10.3 mS/cm, in a split-split plot design with four replicates. In order to calculate soil stress index, soil hydro-physical properties were estimated by HYDRUS- 1D (Vr. 4.17) at depth z dimension (Simunek et al., 2013).ET C was calculated from meteorological data according to FAO (2002). The irrigation interval is each 20: 25 day. 1 Year 2023 3 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( ) II. M aterials and M ethods All the equations used in the materials and methods section are owned to the author 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