By Scout Nelson
Dry weather can increase the risk of nitrate buildup in forage plants. North Dakota State University Extension specialists are advising farmers and ranchers to use extra care when grazing or harvesting drought-stressed forage after rainfall.
Under normal growing conditions, plants take nitrate from the soil and use it to make amino acids and proteins. During dry weather, plant growth slows while nitrate uptake may continue. This can cause nitrates to build up inside the plant.
Rain does not immediately solve the problem. Instead, nitrate levels can increase shortly after rainfall because plants begin growing again while still processing the nitrates already stored in their tissues.
“Following a rain event, nitrate levels may actually spike two to three days after the rain,” says James Rogers, NDSU Extension forage crops production specialist.
Rogers recommends allowing plants seven to 12 days of good growing conditions before grazing. The same recovery period should be considered before cutting forage for hay.
However, waiting does not guarantee that forage is safe. Testing remains important before feeding drought-stressed forage to livestock.
“Even after allowing a seven- to 12-day recovery period following a rain event, do not assume that nitrate concentrations in forage have dropped to a safe level,” says Karl Hoppe, NDSU Extension livestock systems specialist.
Livestock drinking water should also be checked because water containing nitrates can add to the total nitrate risk. Hoppe also recommends knowing the nitrate levels of all hay used in a ration. Mixing hay with known nitrate levels with untested hay can create unexpected risks.
Ashley Ueckert, an NDSU Extension agriculture and natural resources agent, encourages producers to test forage after rain.
For more information about nitrate poisoning, read the NDSU Extension publication “Nitrate Poisoning of Livestock.”
Photo Credit: istock-simplycreativephotography
Categories: North Dakota, Crops, Hay & Forage, Livestock, Weather