Structure

• Algae is a simple aquatic organism that produces its own food through photosynthesis. The body of algae consists of a thallus that attaches to solid surfaces using rhizoids, which resemble hairs. The thallus of algae is responsible for the photosynthetic process that feeds the plant. Algae reproduces by releasing genetic material in the water, where it grows into a new organism. Algae in the soil survive and reproduce in a layer of water contained in or above the soil.
  
  

Conditions

• Algae resides in regions of soil where a stagnant layer of water forms for extended periods. Algae often grows in compacted soil with a composition that does not allow water to drain easily. Soils with a heavy clay content and high fertility are particularly susceptible to algal growth since these soils drain poorly and provide rich nutrients for the algae to grow on.
  
  

Significance

• Land-based algae often attaches to rocks, causing them to break down into soil over time. Specific species of algae are used to create diatomaceous earth, which is an effective form of non-chemical insect control. In lawns and gardens, algae is often a sign of poor growing conditions that can cause weak or thin growth in your plants. Plants in areas where algae has temporarily taken root due to heavy rainfall often experience poor growth after the algae has died back. Large growths of algae often leave behind a dark crust that discourages plant growth after they have died.
  
  

Treatment

• Algae is responds well to treatments of copper sulfate solution. This chemical kills algae, causing it to brown out and die. However, the most effective means of treating algae are preventative in nature. Mechanically aerating your soil with a hoe or other digging tool will improve its drainage and prevent algae from taking hold in the soil. Decreasing the level of irrigation in affected areas or tilling small amounts of gravel into the soil will prevent the layer of water required for soil-borne algae to establish itself.