The authors in the article below (Gainesville Sun, June 4 2017) suggest that better control of fertilizer will solve the pollution problem without resorting to using less. We hope this is the case, but if not, we hope that they consider smaller quantities.
That the DEP has called on agriculture to reduce 4.4 million pounds of fertilizer nitrogen is a wonderful thing. That these retired UF/IFAS Extension nutrient management specialists recognize this is also very positive.
Now, all we have to do, is do it.
Are we willing?
Comments by OSFR historian Jim Tatum.
-A river is like a life: once taken, it cannot be brought back-
Improve farm practices to protect water bodies
By George Hochmuth and Jerry Kidder
Special to The Sun
A truly sobering presentation was made by Florida Department of Environmental Protection officials in Live Oak in April about the excessive level of nitrogen pollution in the lower and middle sections of the Suwannee River and associated springs.
The river has been declared impaired because of algae growth from too much nitrogen. FDEP has prepared a draft basin management action plan that identifies the sources of nitrogen and the amounts of nitrogen each source must stop contributing to the water body.
Principal sources are urban and agricultural fertilizers, manures, septic systems and wastewater. The plan sets a timetable for restoration.
Under the plan, agriculture is required to remove a staggering 4.4 million pounds of fertilizer nitrogen.
Profitable crop production is not possible without nitrogen fertilization. However, the key issue here is not just the amount used but the management of nitrogen fertilization, such as how it is applied, where in the soil it is placed, and when it is applied in relation to crop growth. Rainfall and irrigation are also considerations.
These factors are included in the fertilization recommendations published by the Extension Service of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). Recommendations are based on studies carried out on campus, at research and education centers around the state, and on operating farms. Subsequently, these recommendations were adopted by the Florida Department of Agricultural and Consumer Services as part of their statewide best management practices program. Farmers who pledge to follow the best management practices are presumed not to be polluting the water body.
Although good nutrient management practices have been encouraged for decades, agriculture is still found to be contributing a huge amount of excess nitrogen to the water. How can this be?
We believe that too much attention has been given to the amount of nitrogen recommended and too little to the management practices that are part of the UF/IFAS recommendations. We often hear from farmers and their advisors that the amount of fertilizer recommended is not enough to produce the biggest crop yields. Thus, there is pressure to increase the recommended amount of nitrogen.
The amounts currently recommended are set for maximum yield, provided the management practices are followed. Throwing on more nitrogen to compensate for improper management is counterproductive to the goal of reducing nitrogen losses to ground and surface waters, and is costly to the farmer and to society.
Optimal fertilizer management strategies include the best source of nutrients (for example, synthetic fertilizers, manures, organic, controlled-release), correct placement of the fertilizer near the crop roots to maximize uptake, and correct timing of fertilizer application to coincide with the crop’s ability to take up the nutrients, i.e., not too early or too late in the growth cycle. And, it is of crucial importance to avoid excessive irrigation so nitrogen is not washed out of the root zone. This saves both nitrogen and water.
So, how do farmers reduce the amount of nitrogen they contribute to the river and still get good crop yields?
The answer is better implementation of the nitrogen and irrigation management strategies found in the best management practices, not an increase in the amount of nitrogen used.
Agriculture has a tremendous challenge ahead to reduce its nitrogen load under the basin management action plan. Society has a stake in this process. As taxpayers, our federal and state funds are being used to help pay for irrigation system upgrades, soil moisture sensors, fertilizer application equipment, manure storage and much more. All this assistance should allow agriculture to better implement nitrogen management strategies. Will this be enough?
Agriculture’s future presence in the Suwannee River basin will require full adoption of best management practices by all farmers, not just the progressive ones.
We hope everyone will focus on the challenge most likely to produce positive results, which is fertilizer and water management, not just amounts.
Unless we get the management practices correct, we won’t get the needed reductions in nitrogen in the watershed, and impairment of Florida’s waters will continue.
George Hochmuth and Jerry Kidder are retired UF/IFAS Extension nutrient management specialists living in Gainesville.