Reducing the excessive use of nutrients was the focus of presentations made recently during the annual Agribusiness Showcase and Conference in Des Moines.
Most Upper Midwest farmers are very aware of problems in the “Hypoxia Zone” of the Gulf of Mexico. This area where the Mississippi River discharges into the Gulf is negatively affected by the abundance of nitrate nitrogen (N) and phosphorus (P) found in the river water. Excess nutrients can come from many sources including: sewage treatment plants; soil erosion; deposition of atmospheric nitrogen and fertilizers used on farms; lawns; and golf courses.
The EPA in March 2011 issued a letter to encourage states bordering the Mississippi and Missouri Rivers to reduce contaminants, specifically N and P, found in lakes, rivers, streams and groundwater. Phosphorus is tightly bonded to soil particles, so erosion is the main reason it is found in water. Nitrogen, on the other hand, converts to nitrates and easily leaches down through the soil profile. This allows nitrates to infiltrate groundwater and eventually reach lakes, streams and rivers through tile systems or aquifers.
Below are a few recommendations from experts who spoke at the agribusiness conference:
- Eliminate “insurance” and “build” applications of nutrients. We tend to base our fertilizer needs on soil tests and what our yield goals are, then add an extra 10-20% to make up for losses due to weather, timing, etc. We need to stop this practice.
- Bioreactors at the field’s edge can lower nitrate in runoff water before it can enter a stream or tile drainage ditch.
- Saturated Buffers can help reduce both erosion and nitrate runoff for farms that have a river or stream flowing alongside or through the field.
- Cover Crops can greatly reduce erosion and help with more efficient nitrogen use. Cover crops are one of the few practices that may help an entire field, rather than merely an edge-of-field strategy. Long-term benefits of cover crops include managing weeds, increasing organic matter and building overall soil health.
- Precision Agriculture. Programs like Climate FieldView™ and Latham’s Data Forward™ bring economics and conservation together by using your own farm data. This leads to better variety selection and crop input decisions and often better use of soil and fertilizer resources.
- These are just a few of the most popular strategies, but you could visit with your local NRCS staff member for more ideas. Most state strategies are voluntary, but Minnesota is considering making some of their strategies mandatory. Fall application of nitrogen fertilizer might be the first practice banned in Minnesota.
- One farmer put it very simply, “Either join the effort now and have some freedom in what practices you use or wait until it is mandatory and then be told what to do.”
Contact your Latham RSM or our Technical Agronomist Phil Long to talk about ways our cover crop portfolio or Seed-2-Soil® services can help you and our customers raise the most profitable and sustainable crops.
