The Effect of Algae in Soil

Nitrogen Fixing

• Farmers depend on nitrogen-fixing plants in modern crop rotation to maintain enough plant-accessible nitrogen in the soil for other food and cash crops. Blue-green algae is one of the few plants known to fix nitrogen. It is also very adaptable to almost any situation, just needing relatively wet surfaces on which to grow. As a nitrogen-fixer, cyanobacteria can prove very useful to farmers. Nitrogen fixers break down enzymes containing nitrogen not available to most plants. After being broken down, nitrogen, the most important element to plant growth, is made available to other plant life.

Studies

• Scientific studies on the effectiveness of blue-green algae in the soil have shown that plants do grow better when the soil has a rotation crop of blue-green algae. Regardless of the crop being grown, the introduction of cyanobacteria into the soil has provided a 15 to 20 percent higher crop yield than in non-inoculated soil. Given the adaptability of blue-green algae to diverse climates, it has potential to help re-enrich nutrient-depleted soils. Research on using algae in this way is ongoing.

Positive Effects

• Blue-green algae does more than just fix nitrogen in the soil. It helps to make phosphorous available as well, one of the three most important elements to plant growth, right up there with nitrogen. Additionally, when blue-green algae decomposes, fresh organic matter is introduced into the soil, encouraging the growth of beneficial microorganisms and providing a more sustainably healthy soil.

Popularity

• Despite its having been commercially available for at least half a century, farmers overall have not embraced the concept of using algae as a nitrogen-fixer. Though blue-green algae is especially adaptable, it will only grow for three to four months of the year, and generally, farmers need more readily available fertilizers and nitrogen-fixers. Though there are many benefits to the use of cyanobacteria, it also reproduces fairly slowly when on land, and is somewhat susceptible to harmful bacteria which can be introduced to the soil, hurting other plants. Research and development is ongoing regarding these shortcomings of blue-green algae in agriculture.