What are alternate organic compounds that can be used for the same purpose as Urea and explain the benefits of Urea over the alternates.

Plants need three macro-nutrients for their growth. These
are nitrogen, phosphorus and potassium. Urea is a source for
nitrogen.

Organic alternatives of urea include compost
which is derived by microbial decomposition of organic waste. Organic alternatives to
urea are superior to urea in many ways. They improve the ability of the soil to hold
water, improve its texture, do not cause plant damage due to excessive nitrogen
availability, etc. The nitrogen availability in the soil can also be increased using
nitrogen fixation by growing alternate crops of legumes that have nodules in their roots
which can take nitrogen from the air and convert it to a form that can be used by
plants. The symbiotic relation enriches the soil and eliminates the requirement for a
nitrogen fertilizer.

But these methods are not possible to
use if there is intensive farming of non-leguminous crops and sufficient amounts of
organic manure is often difficult to obtain.

The benefits
of urea which outweigh the benefits of organic fertilizers are that it can be
transported easily as urea has one of the highest concentrations of nitrogen. Urea
releases ammonia which is acted upon by microbes in the soils and converted to ammonium
compounds that can be absorbed by plants. Urea can be easily spread out over the entire
field and if this is done at the right time and the right quantity is used, the
utilization of the nitrogen in the urea is high.