1989). Especially, soil moisture is vital of importance to plant in order to maintain its life processes biologically. Water constitutes 80 to 90% of the fresh weight of most herbaceous plant parts and more than 50% of the fresh weight of woody plants.
On the other hand, increasing population and decreasing water source respectively make the use of water more sensitive. While the demanded of food is increasing with respect to world population, agricultural areas are getting smaller due to higher rural population den- sity (Josephson et al., 2014). Therefore, obtaining …show more content…
To identify the total amount of water in soil, all soil forming factors must be considered. While soil structure and texture
affect the amount of leaching in soil, climate cause water to evaporate from soil to air.
However, a water budget that minimizes water to satisfy crop needs is often a target for crop agriculture (Wysocki et al., 2005). The studies done so far show that there are many agents that affect crop yield and soil forming processes and indicate that crop yields can be affected directly by climate change, root zone moisture, soil forming factors, and applications such as fertilization, irrigation, drainage, seeding type, rotations plants, and so on. While high crop yields can be taken without irrigation from some parts of the United States, it cannot be taken from others. David Granatsteins work shows that dryland farming can be done in some parts of the Northwestern United State under conditions of semiarid or arid climates (Granatstein, 1992). However, the study of Joe Henggeler and Raymond E.
Masseyl shows that the yield can be taken around 40 to 45 % more from irrigated areas when compared with non-irrigated areas in Missouri (Henggeler and Masseyl, 1997). Even all …show more content…
Soil moisture, surface porosity, vegetative growth, and covering rate affect the over ow from a soil surface (Thurow, 1991).
Transpiration (T) is the loss of water vapor from plant surface. Together with the loss of water via evaporation (E) from surrounding soil surfaces, the total loss of water referred to as evapotranspiration (ET) represents the amount of water that the irrigator must supply to ensure that there is sufficient water to meet the needs of the plant (Sanford and Selnick,
2013).
Lastly, percolation is the process of water movement into the soil through soil layers by gravity and capillary forces. When water moves down under root zone, the water cannot be taken by plants that is called as deep percolation (Vaccaro, 2007). While surface runoff affects the soil quality at the surface, all other agents are mainly related to soil water content and ultimately ground water level.
Approximately 52% of the 14000 km2 Alabama Black Belt region is unsuitable for agri- cultural activities because of low hydraulic permeability, high water table, or other restrictive
soil properties such as having shrinking and swelling potential (He et al., 2011). This