Friday, January 24, 2020

Op-Ed: Fertilizer Bill A Good Start, But Science-Based Changes Are Needed To Be Effective

By John R. Lake, Agronomist

Senate Bill 915 (Yaw-R-Lycoming), which sets standards for the application of fertilizer to turf, provides for the certification of professional fertilizer applicators, sets labeling requirements and  establishes an education program, is a good start to addressing the use of soil nutrients for cosmetic purposes. 
Unlike nutrients applied for the production of a harvested commodity, turf, and ornamental applications only serve to provide a more aesthetically appealing landscape without any removal with the exception of grass clippings or landscape trimmings.
I hope to provide the reader with an appreciation for the amendments needed to truly meet this bill’s intended goal of reducing nutrient pollution of surface and groundwater, while maintaining the ability to maintain an attractive property and recreation areas.
Applied Nitrogen Limits
First let’s start with a basic law of agronomic science.
 Justus von Liebig's Law of the Minimum (1840) states that yield is proportional to the amount of the most limiting nutrient, whichever nutrient it may be. 
From this, it may be inferred that if the deficient nutrient is supplied, yields may be improved to the point that some other nutrient is needed in greater quantity than the soil can provide, and the Law of the Minimum would apply in turn to that nutrient.
Prior to the application of any fertilizer a soil test must be performed to establish what nutrients are needed, and what nutrients may be present in high to excessive levels.
Therefore, the amount of nutrients allowed must be specified by a soil test which helps sets limits the rate of highly mobile nitrogen, and prohibit application under weather and soil conditions where the applied nutrients are highly likely to move to surface water.
Applying this Law, Section 6851 should be amended to delete the language allowing fertilizers to be applied to the top of a streambank.
Section 6852 should be changed to add a provision limiting total applied nitrogen to 1 pound per 1,000 feet or less annually, unless soil tests results indicate a higher rate for a specific site is warranted.  In no case should more than 2 pounds per 1,000 square feet be applied in any one year.
Soil pH Levels
Next, the soil must have a pH within a range that is favorable to plant growth.  Failure to do so will ensure nutrients will not be taken up by grass and will be free to be lost to the environment.
Some examples of pH levels recommended by Penn State include: Annual Bluegrass 6.5; Perennial Ryegrass 6.5; Bentgrass 6.0; Tall Fescue 6.5; Bermuda 6.5; Zoysiagrass 6.5; Fine Fescues 6.0; Mixed cool season 6.5; and Kentucky Bluegrass 6.5.
Therefore, Section 6852 needs to be amended to prohibit the application of fertilizer, unless the soil pH has been adjusted to a pH of between 6 and 7.
If soil pH is not within these limits, then nutrients will be released into the environment.
The bill proposes fertilizer applicators be qualified to provide fertilizer application, or supervise the application. This attempt to establish a certification requirement must be appropriate to the agronomic skill set needed for this task.
As a result, the definition of a certified fertilizer applicator must also include a reference to an individual certified by the American Society of Agronomy or someone who holds a degree in turf science, agronomy or horticulture and who has passed an exam approved by the Department of Agriculture.
The provisions related to allowing pesticide certified individuals to qualify for fertilizer applicators is not appropriate because they have a different background and skill set.
Local Government Authority
Finally, this bill would strip local governments of the authority to address special environmental concerns that are area specific. 
Local governments must be able to establish more restrictive requirements to address special local environmental concerns such as eutrophication of ponds, lakes, or other surface or groundwater nitrate levels.
This provision should be removed from the bill to allow the local community the authority to take more stringent measures where the need is justified.
Thank you so much for taking the time to read and consider these recommendations and opinions offered by the author. 
This does not represent the opinion or is this endorsed by any other group or individual.
Click Here for a copy of the recommended language applied to the appropriate section of the bill.
(Photo: John Lake teaching along the banks of Letort Spring Run in Cumberland County.)

John R. Lake is a retired Agronomist formerly with the Department of Agriculture.  He can be contacted by sending email to:

Related Article:
[Posted: January 24, 2020]  PA Environment Digest

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