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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 ...
One would not want the water table to be too shallow to avoid crop yield depression nor too deep to avoid drought conditions. This is a subject of drainage research. The figure shows that a seasonal average depth of the water table shallower than 70 cm causes a yield depression [5] The figure was made with the SegReg program for segmented ...
RSC should not be higher than 1 and preferably less than +0.5 for considering the water use for irrigation. [5] The formula for calculating RSC index is: RSC index = [HCO 3 + CO 3] − [Ca + Mg] RSC index = HCO 3 /61 + CO 3 /30 – Ca/20 – Mg/12 (in case the ionic concentrations are measured in mg/L or ppm as salts)
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.
The sodium adsorption ratio (SAR) is an irrigation water quality parameter used in the management of sodium-affected soils.It is an indicator of the suitability of water for use in agricultural irrigation, as determined from the concentrations of the main alkaline and earth alkaline cations present in the water.
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.
The Global Climate Observing System specified soil water as one of the 50 Essential Climate Variables (ECVs). [18] Soil water can be measured in situ with soil moisture sensors or can be estimated at various scales and resolution: from local or wifi measures via sensors in the soil to satellite imagery that combines data capture and ...
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.