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Pores (the spaces that exist between soil particles) provide for the passage and/or retention of gasses and moisture within the soil profile.The soil's ability to retain water is strongly related to particle size; water molecules hold more tightly to the fine particles of a clay soil than to coarser particles of a sandy soil, so clays generally retain more water. [2]
Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. The soil moisture curve is characteristic for different types of soil, and is also called the soil moisture characteristic. It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability.
The major river in Ethiopia is the Blue Nile. However, most drinking water in Ethiopia comes from ground water, not rivers. Ethiopia has 12 river basins with an annual runoff volume of 122 billion m 3 of water and an estimated 2.6–6.5 billion m 3 of ground water potential.
A relatively low rate of change indicates when macropore drainage ceases, which is called Field Capacity; it is also termed drained upper limit (DUL). Lorenzo A. Richards and Weaver [5] found that water content held by soil at a potential of −33 kPa (or −0.33 bar) correlate closely with field capacity (−10 kPa for sandy soils).
It is not known exactly to what extent dams in Ethiopia would reduce the flow of water to Sudan and Ethiopia. Assuming an evaporation rate of 1 meter per year, an irrigated area of 200,000 hectares and a combined reservoir area of 1,000 km2, the flow of the Nile could be reduced by 3 billion cubic meters per year, equivalent to about 5 percent ...
The reduced soil protection by vegetation cover, combined with steep slopes and erosive rainfall has led to excessive soil erosion. [12] [17] [18] Nutrients and organic matter were lost and soil depth was reduced. Hence, soil erosion is an important problem, which results in low crop yields and biomass production.
Water holding capacity may refer to: Available water capacity; Meat water holding capacity; Field capacity This page was last edited on 29 ...
It is also known as available water content (AWC), profile available water (PAW) [2] or total available water (TAW). The concept, put forward by Frank Veihmeyer and Arthur Hendrickson, [ 3 ] assumed that the water readily available to plants is the difference between the soil water content at field capacity ( θ fc ) and permanent wilting point ...