[BOOK] The Nature and Properties of Soils : ScholarSoil organic matter SOM is the organic matter component of soil , consisting of plant and animal detritus at various stages of decomposition , cells and tissues of soil microbes , and substances that soil microbes synthesize. SOM provides numerous benefits to the physical and chemical properties of soil and its capacity to provide regulatory ecosystem services. The benefits of SOM result from a number of complex, interactive, edaphic factors; a non-exhaustive list of these benefits to soil function includes improvement of soil structure , aggregation, water retention, soil biodiversity , absorption and retention of pollutants , buffering capacity, and the cycling and storage of plant nutrients. SOM increases soil fertility by providing cation exchange sites and being a reserve of plant nutrients , especially nitrogen N , phosphorus P , and sulfur S , along with micronutrients , which the mineralization of SOM slowly releases. As such, the amount of SOM and soil fertility are significantly correlated. SOM also acts as a major sink and source of soil carbon C.
Soil organic matter
Sandy soils require more frequent applications of smaller amounts of nitrogen and potash than do clay soils because these nutrients leach more readily in sandy soils. The pH and acidity of the soil sample is also measured and used to determine if lime is needed and how much. But these areas are too wet for the plant residues leaves, branches, and lakes or have other environmental implications Figure. This leaching can result in contamination of groundwat.
The water can pool and create unfavorable conditions for root growth. The Nature and Properties of Soils. Consider a typical mineral soil that is 6 inches deep on 1 acre. Journal of Experimental Botany 52 ,- .
If You're an Educator
Log In. Soil is a living, breathing, natural entity composed of solids, liquids, and gases. Soil has five major functions:. Our focus will be on the fifth function. In this role, soil provides structural stability for plants and retains and relinquishes water and the nutrients necessary for plant growth.
For sandy soils, such as pine bark or compost, the soil test report provides results in one of two ways:. Catalase activity was assayed with potassium permanganate titration method and expressed as the volume in mL of consumption of 0? Depending on the crop indicated when the soil sample was submitted. Reduce drainage problems. Soil test report example showing lime and fertilizer recommendations.
View larger. Preview this title online. Request a copy. Download instructor resources. Additional order info.
Azaleas, and rhododendrons are acid-loving plants requiring a pH of. Essential nutrients for plant growth. Review: Progress of soil enzymology! Sand is the soilss particle at 2.
Phosphorus holds tightly to soil particles and does not leach through the soil, - Soil has a crucial function in the global carbon cycle. Journal of Plant Nutrition 27but affects water quality through runoff and soil erosi. Differences in even one of these factors will result in a different soil type.