The process of keeping nitrogen available to nourish your crops is complicated. Variables such as weather, soil type and soil microbe population can all have an impact on how nitrogen can be lost. This diagram illustrates how nitrogen is made available for plants as well as the various mechanisms for loss.
This occurs when the soil’s urease enzymes break the urea molecules
into ammonia gas. Up to 40% of surface-applied urea-based nitrogen
not incorporated into the soil via rainfall, irrigation or deep
mechanical incorporation can be lost through volatilization.
This type of loss can occur with every soil type.
This form of nitrogen loss happens when negatively charged nitrate
is moved below the plant’s root zone by percolating water.
Leaching is most common in sandy soils.
This form of nitrogen loss occurs when nitrate nitrogen is converted
back to gaseous forms. The nitrogen diffuses out of the soil and is lost
into the atmosphere. Denitrification occurs in soils that are poorly
drained or become waterlogged.