Search results
Results from the WOW.Com Content Network
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 fraction of water held back in the aquifer is known as specific retention. Thus it can be said that porosity is the sum of specific yield and specific retention. Specific yield of soils differ from each other in the sense that some soil types have strong molecular attraction with the water held in their pores while others have less.
Soil moisture is a general term describing the amount of water present in the vadose zone, or unsaturated portion of soil below ground. Since plants depend on this water to carry out critical biological processes, soil moisture is integral to the study of ecohydrology.
Water moves in soil under the influence of gravity, osmosis and capillarity. [7] When water enters the soil, it displaces air from interconnected macropores by buoyancy, and breaks aggregates into which air is entrapped, a process called slaking. [8] The rate at which a soil can absorb water depends on the soil and its other conditions.
The nominal definition of field capacity (expressed symbolically as θ fc) is the bulk water content retained in soil at −33 kPa (or −0.33 bar) of hydraulic head or suction pressure. The term originated from Israelsen and West [ 1 ] and Frank Veihmeyer and Arthur Hendrickson.
Sufficient soil depth for adequate root growth and water retention; Good internal drainage, allowing sufficient aeration for optimal root growth (although some plants, such as rice, tolerate waterlogging); Topsoil or horizon O is with sufficient soil organic matter for healthy soil structure and soil moisture retention;
Soil physics is the study of soil's physical properties and processes. It is applied to management and prediction under natural and managed ecosystems . Soil physics deals with the dynamics of physical soil components and their phases as solids , liquids , and gases .