Reducing Fertilizer Loss

by Patrick Kirchhofer, Peoria County Farm Bureau

Planting season is here. Typically, the ideal time for central Illinois farmers to plant corn and soybeans spans a four-week time period from April 15th to May 15th. Farmers focus first on getting corn planted, followed by soybeans.

Surrounding the busy planting season is the application of fertilizer. Much has been learned about which fertilizers are needed by corn and soybeans and the amount needed, but there is still much to learn about this process. Questions arise, such as: When is the best time to apply nitrogen? Should fertilizers be split-applied, or in other words, apply smaller volumes more often? How do fertilizers dissolve in the soil, and how are they utilized by the plants? How is fertilizer lost through excess rainfall and soil erosion? What can farmers do to decrease the amount of fertilizer lost from farm fields? How effective is the use of no-till, cover crops, water retention basins and the like in reducing fertilizer loss?

One such collaborative effort is the Illinois Nutrient Loss Reduction Strategy (NLRS), developed in response to the U.S. Environmental Protection Agency’s 2008 Gulf Hypoxia Action Plan, which calls for each of the 12 states in the Mississippi River Basin to produce a plan to reduce the amount of phosphorus and nitrogen carried in rivers throughout the states and to the Gulf of Mexico. In 2011, the EPA provided a recommended framework for state plans. Illinois’ strategy follows this framework.

The Illinois NLRS working group convened in March of 2013. There are 25 members on this working group representing diverse backgrounds, including representatives from sanitary districts, university faculty, environmental groups, the EPA and farm commodity groups.

The key strategy of this plan is a study of best management practices for reducing loads from agriculture and urban runoff and wastewater treatment plants. Implementation of these practices will help Illinois reduce our phosphorus losses by 25 percent and nitrate-nitrogen losses by 15 percent by 2025. The eventual target is a 45-percent reduction in the loss of the nutrients to the Mississippi River. The actions will also assist in addressing water quality problems in Illinois rivers, lakes and streams.

The plan identifies priority watersheds in Illinois for nutrient loss reduction efforts, although every acre in Illinois is critical to implementing a successful strategy. Illinois has 22 million acres in crop production and is often No. 1 or 2 in corn and soybean production.

There are all sorts of acronyms used in our society, and agriculture has its share. One is "KIC by 2025," developed by the Illinois Council on Best Management Practices in the fall of 2011. KIC stands for "Keep It for the Crop by 2025,” referring to keeping fertilizer on farm fields for utilization by the crops instead of being lost through water runoff and soil erosion.

KIC utilizes the 4R nutrient stewardship principles. The four Rs are: 1) right source (balanced supply of essential nutrients); 2) right rate (decisions based on soil nutrient supply and plant demand); 3) right time (decisions based on dynamics of crop uptake); and 4) right place (addresses root-soil dynamics and nutrient movement in soil).

In addition, there are many ongoing field demonstrations throughout Illinois showing how the farm community can reduce nutrient losses and improve water quality, yet feed a growing and demanding world population. iBi