Originally Posted by http://desertgardens.suite101.com/blog.cfm/organic_vs_synthetic_fertilizers

There are some benefits to using organic fertilizers.



Compared to synthetic fertilizers, organic fertilizers have lower levels of actual nutrients. So, on the face of it, one would think that synthetic might be better.
However, organic fertilizers perform some important functions that synthetic fertilizers do not.
For instance, organic fertilizers increaseorganic content of the soil. By doing so, they increase the soil’s capacity to supply nutrients and other elements essential to plant growth and survival.
They improve the actual structure of the soil. Adding organic fertilizers help soil retain water, absorb oxygen and also help to provide adequate drainage.
Dry, alkaline desert soils can be almost devoid of microbial life. Organic fertilizers also help to increase the level of beneficial bacteria and fungi in the soil. In particular, organic fertilizers also increase mycorrhiza fungi, which create a symbiotic relationship with the roots of plants, and greatly enhance a plant’s ability to grow, absorb nutrients and to make fruits and flowers.