Organic Matter and Factor Affecting Organic Matter in Soil

Organic Matter

Soil organic matter is composed of decomposing residues (plants and animals), by-product formed by decomposition, microorganisms and materials resistant to further decomposition. Generally, a mineral soil contains 2-5 %organic matter. Organic matter plays a variety of roles in nutrient, water and biological cycles in soil system.
Source of organic matter: common organic waste materials which could be used to increase soil organic matter include animal manures, crop residues, composts, green manure, sewage sludge, food processing wastes, industrial organic wastes, wood manufacturing wastes and municipal wastes.

Factor Affecting Organic Matter in Soil

The amount of organic matter in soil is the result of two processes: the addition of organic matter and the loss of organic matter through decomposition. The following four factors affect both addition and losses.
Management
                Practices that increase plant growth on a field (cover crops, irrigation, etc.) will increase the amount of roots and residues added to the soil each year. On the other hand, intensive tillage decrease organic matter by speeding up decomposition.
Soil texture
                Fine-textured soils can hold much more organic matter than sandy soils. Decomposition occurs faster in well aerated sandy soils. A sandy loam rarely holds more than 2 % organic matter.
Climate
                High temperature speeds up the degradation of organic matter. In areas of high precipitation there is more plant growth and therefore more roots and residues are added to the soil as source of organic matter.
Vegetation

                In grasslands, organic matter is added to the soil each year from grass roots that extend deep into the soil. In forests, the organic matter comes from leaves that are dropped on the surface of the soil. 

Popular posts from this blog

Grafting Method - Inarching or Approach Grafting

Image
Inarching or Approach Grafting Unlike other grafting operations, in inarching the scion is attached to the stock while it is still attached to the parent plant. Round the world, the method has been extensively used in the vegetative propagation of mango. The method involves potting healthy one-year- old seedling in earthen pots, which are usually 12 in deep and 8 in wide at the top. The earth ball along with root system is kept intact and placed in the pot. The unfilled space in the pot is then filled with a mixture of well- rotted manure and canal silt. The soil is firmly pressed around the earth ball and the transplanted seedlings are then watered. Potting of seedlings is usually done one month ahead of actual inarching operations. This allows sufficient time for the seedlings to set before grafting. Inarching can either be done in the spring months or in the rainy season. July and August are preferred over the spring season because after inarching operations in the spr...
Read more

Parent Material of Soil

Image
Parent Material of Soil Unconsolidated product of weathering from which soil develops is called parent material. Generally there are two groups of parent materials, i.e. sedentary and transported. The transported materials are further subdivided according to transporting agency and place of deposition. Sedentary or Residual                                            The parent material formed in place and still at the original site. Transported                       The parent material carried and deposited by various transporting agencies. By gravity- Colluvial By water- Alluvial By ice- Glacial By wind- Eolian The nature and properties of parent material together with climate are the most important factors affecting the kind and quality of soils. So to understand soils we must know the...
Read more

Green Manuring

Image
Green Manuring A growing crop that is plowed under and mixed with soil to enrich the organic matter is called green manure crop. The practice of plowing under or soil incorporation of such green manure is called green manuring. Green manures are mostly leguminous crops which are high in nitrogen contents. Generally following crops are suitable for green manuring: Jantar, Guara, Cow peas, Alfalfa, Sun hemp and Clover etc. Criteria for the selection of green manure crops It should be fast growing and easily established. It should produce abundant and succulent biomass. It should be well adapted to the local conditions. Growth habit of crop should encourage ground cover soon after its establishment. It should be able to fix nitrogen in the soil. It should have a wide climatic and soil adaptation and ability to grow on poor soil. Advantages Improves the soil fertility Adds nutrients and organic matter to the soil Improves the soil structure Improves soil aer...
Read more