Factors That Influence the Decomposition Rate of Organic Matter from the Soil

Wholesome soil is living dirt, teeming with family items from microscopic bacteria to earthworms. These garden residents play an significant part in breaking down materials in the soil, releasing nutrients your plants will need to grow, as well as improving the structure of the soil to permit water and oxygen to nourish plant roots. Organic matter in the soil feeds these animals and is essential for healthy garden dirt. Understanding how organic matter breaks down helps you meet your garden’s soil needs.

Biological Activity

The most obvious cause of the break down of soil organic matter is a high degree of biological activity: A high number of bacteria, fungi, and bigger organisms feeding on the organic material on your soil for food. A biologically active soil is a nutritious soil, in order to raise the soil in your lawn, you should expect a quicker decomposition of organic matter. Anything that has an effect on the microbes and other living organisms in your soil, consequently, will affect the speed of organic matter break down.

Oxygen Level

Like all living beings, the creatures on your soil need oxygen to live. Oxygen comes in the air above the dirt, so there must be a way for air to penetrate into the dirt. Soil having a loose structure allows for ample spaces between soil particles to get oxygen to gather. In such cases, organic matter will decompose quicker. Compacted or “tight” soils — like soils with a high clay content — don’t offer sufficient space for air to gather, causing less biological activity and a slower organic matter break down.

Moisture Level

The total quantity of water from the soil, both directly and indirectly, affects the decomposition rate of organic matter. Indirectly, a moist soil results in a slower split down since water fills the air spaces in the soil, depriving the microbes of oxygen. But all living beings also need water, so a soil that’s too dry directly decreases organic matter decomposition, as the microbes found in soil cannot survive without water. Soils that undergo interval dry and moist periods — such as a lawn which you just water weekly — instead of staying constantly moist or dry, will cause organic matter to decompose faster.

Soil pH

The pH of the soil lets you know how acidic or alkaline soil conditions are. A very low pH indicates an acidic soil, and that may have a significant impact on the decomposition of organic matter. Sensors — the organisms most responsible for breaking down organic matter — experience a sharp drop-off in activity once the pH falls below 6.0.


At temperatures of 40 degrees Fahrenheit and above, dirt microbes experience a few activity. But after temperatures reach 70 F, soil microbes really get going up to approximately 100 F. Microbial populations double in the soil with each extra 10 F. Because of this, soil organic matter breaks down quicker in the summer, and regions using year-round warm weather will decompose more natural matter annually than areas which experience cold winters.

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