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Alpha is also a function of the number of items, so shorter scales will often have lower reliability estimates yet still be preferable in many situations because they are lower burden. An alternative way of thinking about internal consistency is that it is the extent to which all of the items of a test measure the same latent variable .
Cronbach's alpha (Cronbach's ), also known as tau-equivalent reliability or coefficient alpha (coefficient ), is a reliability coefficient and a measure of the internal consistency of tests and measures. [1] [2] [3] It was named after the American psychologist Lee Cronbach.
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.
Soil particle density is typically 2.60 to 2.75 grams per cm 3 and is usually unchanging for a given soil. [44] Soil particle density is lower for soils with high organic matter content, [45] and is higher for soils with high iron-oxides content. [46]
Soil chemistry is the study of the chemical characteristics of soil.Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1870s a consulting chemist to the Royal Agricultural Society in England, named J. Thomas Way, performed many experiments on how soils exchange ions, and is considered the father of soil chemistry. [1]
Salts dissolved from the soil accumulate at the soil surface and are deposited on the ground and at the base of the fence post. Saline incrustation in a PVC irrigation pipe from Brazil. Soil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. [1] Salts occur naturally within soils and ...
Plants are susceptible to such localized calcium deficiencies in low or non-transpiring tissues because calcium is not transported in the phloem. [1] This may be due to water shortages, which slow the transportation of calcium to the plant, poor uptake of calcium through the stem, [2] or too much nitrogen in the soil. [3]
Global variation in soil pH. Red = acidic soil. Yellow = neutral soil. Blue = alkaline soil. Black = no data. Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics.