In class we briefly talked about the effects adding organic matter to soil. Adding organic material to soil can increase biological activity. The microorganisms break down the organic material through a process called decomposition, which turns the organic material into useable nutrients for the soil. These microorganisms are also active in the killing of soil borne diseases.
Decomposition can also increase the ability of the soils to form into aggregates. The aggregate structure is the most desirable structure for promoting plant growth. This structure allows air and water to move freely through the structure. By improving aggregation of the soil, you have improved soil tilth. Soil tilth is the ability of organic matter to hold water and nutrients, help establish and maintain a strong granular structure, provide nutrients as decomposition takes place, and to buffer the effects of organic contaminants. All of this provides an area for plants to germinate and grow roots that will promote a healthy plant.
Soil humus can also be formed through decomposition. Humus is made of humic and non-humic substances. The non-humic substances are made up of polysaccharides, proteins, and lignin’s in their natural or transformed states. The humic substances can be broken down into four categories. The first is fulvic acid. This type has the lowest carbon and nitrogen content, but the highest oxygen content. Fulvic acid is soluble in both an acid and a base. The second type is humic acid. It is the most average of all the types of humus and is insoluble in acid and soluble in a base. The third type is humin. Humin has the highest carbon and nitrogen content, but the lowest oxygen content. Lastly, the most recently found type of humic substance, Glomalin. Which will be what my next post is about, unless someone informs us on this topic within the next week or so.