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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]
On the level of a complete ecological niche or ecosystem, nutrient depletion can also come about via the loss of the nutrient substrate (soil loss, wetland loss, etc.). Nutrients are usually the first link in the food chain, thus a loss of nutrients in a habitat will affect nutrient cycling and eventually the entire food chain. [2] [3]
Nutrients in the soil are taken up by the plant through its roots, and in particular its root hairs.To be taken up by a plant, a nutrient element must be located near the root surface; however, the supply of nutrients in contact with the root is rapidly depleted within a distance of ca. 2 mm. [14] There are three basic mechanisms whereby nutrient ions dissolved in the soil solution are brought ...
Specific soil management practices that affect soil health include: [17] Controlling traffic on the soil surface helps to reduce soil compaction, which can reduce aeration and water infiltration. Planting cover crops that keep the soil anchored and covered in off-seasons so that the soil is not eroded by wind and rain.
In agriculture, leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.
The rhizosphere is an "area of concentrated microbial activity close to the root" and where water and nutrients are readily available. [5] Plants exchange carbohydrates for nutrients excreted by the microbes, different carbohydrates support different microbes. [5] Dead plants and other organic matter also feed the variety of organisms in the ...
They sequester nitrogen and other nutrients that might otherwise enter groundwater, and they fix nitrogen from the atmosphere, making it available to plants. Many organisms enhance soil aggregation and porosity, thus increasing infiltration and reducing surface runoff. Soil organisms prey on crop pests and are food for above-ground animals.
The effect of pH on a soil is to remove from the soil or to make available certain ions. Soils with high acidity tend to have toxic amounts of aluminium and manganese. [116] As a result of a trade-off between toxicity and requirement most nutrients are better available to plants at moderate pH, [117] although most minerals are more soluble in ...