Another good reason most people do not use animal or human urine is health concerns although animal or human urine is perfectly safe to use as long as the donor is healthy. While it is understandable why we use Urea as a urine substitute the negatives far out weigh the positives. 6 Increases disease activities 7 Urea breaks down into various compounds some of which can inhibit plant growth. Eventually decreases plant production 9 Decreases nutritional values of plants to humans while increases nutritional value to pests. 10.The carbon in Urea based fertilizers is chemically converted to CO2 and lost to the atmosphere.
Carbon is energy to plants and soil micro-organisms.
It is a mistaken idea that more nitrogen is better then less. What you must understand is how nitrogen is available in nature and how plants and soil organisms use it. Nitrogen is produced freely in nature by various mechanisms found in nature. The most obvious sources of nitrogen is animal manure. Another source is bacterial action.