As described in the “Agency Background” document, page 3, one of the purposes of the VDACS report was to “(i) conduct an assessment of the most effective means to encourage the use of slowly available nitrogen in lawn fertilizer and lawn maintenance fertilizer”. However, the annual nitrogen rate limits in the 2014 draft “Standards and Criteria” may actually have the opposite effect, discouraging the use of slow release fertilizers.

Both the 2005 and 2014 versions of the Standards and Criteria have recommended annual N rates of 3.5 or 4.0 lbs N per 1000 ft² for cool or warm season turf, respectively. The 2005 version had an additional sliding scale that allowed N rates up to 5.0 lbs (cool-season) or 5.5 lbs (warm season) when using slow release fertilizers (pg. 98). This increased allowance recognized the fact that these products pose limited risk to water quality impairment. The sliding scale has been removed from the 2014 version, and the new 80% limitation for slow and controlled release/enhanced efficiency fertilizers (pg. 98) would reduce slow release N rates further, to 2.8 and 3.2 lbs, respectively (rate reductions of 44% and 42% from the 2005 version). Higher annual N rates of 3.5 and 4.0 lbs (cool and warm season turf) would be allowed for readily available N than for slow release N. This seems counter-intuitive from a water quality perspective.

Research has repeatedly shown that slow release/enhanced efficiency fertilizers reduce the risk for water quality impairment, and this fact is recognized by all parties involved in this process. Limiting the rates of slow release N to levels that may not be agronomically sufficient, depending on specific product technology, could actually discourage the use of these products, and encourage exclusive use of readily available N sources instead. This unintended result would be in complete opposition to one of the primary goals of the entire process.

Two potential resolutions exist: remove the 80% limitation in the 2014 version, allowing all products to be applied at the same annual N rates; or keep the 80% limitation, but base it on the higher 2005 rates, resulting in annual N rates of 4.0 (cool season) or 4.4 (warm season) lbs N per 1000 ft² when using slow or controlled release/enhanced efficiency N sources. The latter approach would provide a true incentive to the use of these more environmentally responsible products.