The advantages of the natural atmospheric nitrogen fixing by algae are thus:

Nitrogen is often called the „engine of plant growth “.
Higher yields are produced by the addition of nitrogen. Nitrogen is also a substantial component of protein, 16% of crude protein is nitrogen.

high nitrogen demand of plants becomes a limiting factor in the process of organic agriculture, since organic fertilization, or the use of legumes, cannot supply the required nitrogen. The consequences of a lack of nitrogen are lower protein contents and a biological inferiority of the protein.

One can recognize a lack of nitrogen by a light green to yellowish color in the leaves, small tillering, and early ripening.

In order to avoid a nitrogen surplus, which develops after over fertilization, the manure spreading guidelines of the chamber of agriculture in Austria were strictly followed in our experiment. Excess nitrogen can also cause less strength, and sugar as well as decreased durability of the harvested products.

The necessary fertilizer quantity for a specific crop computes itself as follows:

The nitrogen need of the crop minus the organic nitrogen set free from the soil and the remainders of past harvested crops.
Average recommended fertilizer by corp (chamber of agriculture Austria)

Average nitrogen content of fertilizer by yield

In greenhouses nitrogen is supplied by the soil and irrigation systems. This kind of fertilization takes place with dissolved mineral nitrogen and the other necessary nutrients such as P, S etc. (often by blanket fertilizers).

The nutritive solution of our Cyanobacteria could replace this fertilization method and reduce the oil-intensive production of nitrogen.

The blue algae nitrogen exists bound in amino acids.

Because ground humus consist to a large part of amino acids, the formation of nitrogen positively affects the formation of humus.

In modern high yield agriculture with crop rotation and humus loving crops, the humus and nutrient content of the soil are gradually decreased.

The N-fertilizer produced by blue algae could offer an improvement.

With it not only do the ground fertility and yields become secured but also it binds CO₂ with the humus. 

In the greenhouse one could, with a well co-ordinated irrigation system, fertilize and water the plants at the same time. This “fertilization water” would be most valuable, because - beside the nitrogen – it would also contain the nutrients from the solution in which the Cyanobacteria grew. These trace elements would be particularly beneficial for the greenhouse crops.

Sources:
www.duengung.net