It is generally recognized that lawn fertilizers containing slowly available forms of nitrogen provide increased protection against nutrient loss than water soluble/readily available nitrogen products, particularly when used at equivalent nitrogen application rates.  It is therefore desirable to encourage the use of products containing slowly available nitrogen.  We believe this was the objective of the Virginia Department of Ag and Consumer Services study and report of December 2011, and the subsequent Virginia Nutrient Management Standards and Criteria draft regulation.  

 

Upon review of the documents however, the current draft rule can be interpreted as limiting slowly available nitrogen products to lower annual application rates (80%) than their water soluble counterparts.  If this limitation is correct and  enacted, we believe that it would discourage manufacturers and users from using slowly available nitrogen.  The rule under this interpretation would limit flexibility in use and overall turf quality (also negatively impacting nutrient loss via thinner turf).

 

The draft rule also recognizes that products containing slowly available nitrogen can be used in a single application at rates up to 2.5 lbs N per 1000 sq ft providing the water soluble portion of the product is limited to 0.7 lbs N per 1000 sq ft, due to their increased nutrient loss protection properties.  However, it continues to repeat the 80% annual application rate limit, which would in effect limit a product of this design to one application annually.  We do not believe that this was the intention of the rule.

 

Our suggestion is that either the 80% limitation be removed, or a limit more in line with previous regulations allowing higher application rates for products containing slowly available nitrogen be incorporated.  We feel these changes are necessary to achieve the overall goal of increased use of lawn fertilizers with slowly available nitrogen that protect against nutrient loss.

 

Thank you for your consideration.