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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 quality of irrigation water is very important to maintain soil fertility and tilth, and for using more soil depth by the plants. [26] When soil is irrigated with high alkaline water, unwanted sodium salts build up in the soil which would make soil draining capacity very poor.
Nitrogen fertilizer being applied to growing corn in a contoured, no-tilled field in Iowa.. Nutrient management is the science and practice directed to link soil, crop, weather, and hydrologic factors with cultural, irrigation, and soil and water conservation practices to achieve optimal nutrient use efficiency, crop yields, crop quality, and economic returns, while reducing off-site transport ...
A maize crop yielding 6–9 tonnes of grain per hectare (2.5 acres) requires 31–50 kilograms (68–110 lb) of phosphate fertilizer to be applied; soybean crops require about half, 20–25 kg per hectare. [21] Yara International is the world's largest producer of nitrogen-based fertilizers. [22]
Food production per capita since 1961 Grain silos Rice plantation in Thailand Cambodians planting rice, 2004. Agricultural productivity is measured as the ratio of agricultural outputs to inputs. [1] While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural ...
Base-cation saturation ratio (BCSR) is a method of interpreting soil test results that is widely used in sustainable agriculture, supported by the National Sustainable Agriculture Information Service (ATTRA) [1] and claimed to be successfully in use on over a million acres (4,000 km 2) of farmland worldwide.
Pore water pressure (sometimes abbreviated to pwp) refers to the pressure of groundwater held within a soil or rock, in gaps between particles . Pore water pressures below the phreatic level of the groundwater are measured with piezometers. The vertical pore water pressure distribution in aquifers can generally be assumed to be close to ...
Newmark's Influence Chart is an illustration used to determine the vertical pressure at any point below a uniformly loaded flexible area of soil of any shape. This method, like others, was derived by integration of Boussinesq's equation for a point load.