The Effect of Decaying Plant Life on Soil

Soil is made up of decomposing organic plant and animal material mixed with minerals from tiny rock fragments. Soil is constantly washed and blown away in a process known as erosion. To stay healthy and rich enough in nutrients for plants to grow, soil needs a constant supply of decaying plant and animal matter. The effect of decaying plants on soil is positive because the rotting plant matter adds to the soil and enriches it with nutrients.

The first effect on soil from decaying plants is when water leaches from the rotting plant material into the soil. The carbon compounds found in water within the plant gradually seep from the rotting plant to enrich the surrounding soil. As water escapes from the decaying plant, leaves and stems wither and turn yellow and brown.

Micro-organisms in the soil latch onto the decaying plant and start to break-up the remaining structure of the plant into smaller fragments that add to the content of the soil. This microbial action helps compost the decaying plant material into the soil rapidly, releasing the nutrients stored in the plant.

Following the decay of the soft and watery elements of the plant into the soil, only the stringy and woody cellulose of the rotting plant remains. This soon decays into the soil through chemical alteration by microbes and the action of fungi. This material rots down and adds to soil at different rates. For example, a wooden branch takes much longer to decay into the soil than the remains of a flower stem. The chemical and fungal alteration of the plant cellulose releases more nutrients and matter into the soil. Slowly decomposing matter in soil is known as humus.

The speed at which a decaying plant effects the surrounding soil depends greatly on temperature and moisture levels. Plant decay occurs more quickly in warm conditions. Cold or freezing conditions will slow or even stop the process. Moisture also quickens the pace of plant decay, washing the decomposing nutrients into the surrounding soil.