I remember one of the first times I learned about silage leachate and how toxic it can be to aquatic life. Luckily, my first experience wasn’t looking at a bunch of dead rotting fish trying to get out of their polluted homes. I was simply reading about it, and talking about conservation practices to help prevent this from occurring. We all know how important silage is on the farm, and that it is necessary to feed livestock. What we don’t all realize is the deadly nature of the leachate if it enters into water sources.
The silage isn’t so much the problem, it’s the juices that flow from the mix, what is referred to as leachate. It may sound crazy, but just one ton of corn silage has the potential to produce 7.5 gallons of silage leachate. A Michigan State University publication states; “Silage leachate is an organic liquid that is formed when water, or in some cases pressure from the structure, comes in contact with silage and runs off. “Leachate can be formed as a part of silage storage, especially if the corn or alfalfa is harvested too wet. Water comes in contact with the silage because it is part of the silage. “The other source of leachate is rain water coming in contact with silage and carrying nutrients with it. This leachate has a high biological oxygen demand, BOD. “If silage leachate is allowed to reach surface water, oxygen in the water will be consumed so quickly that anything living in the water, including fish, could immediately be in peril. “It is estimated that one gallon of silage leachate can lower the oxygen content of 10,000 gallons of river water to such an extent that there is a chance for fish kill. Leachate also can cause algal blooms that will further deplete the oxygen levels of surface water and it can also produce high levels of ammonia which will also cause fish kill.”
It goes without saying, hindsight is always 20/20. But I also believe knowledge is power. Now is the time to check your bunkers, silage bags, containment systems and storage facilities. Do you know where your outlets go? Where are the tiles leading to? Where is the leachate heading? According to the Minnesota Pollution Control Agency, “Corn silage leachate has a high BOD value, ranging from 12,000 to 90,000 mg/L, approximately 200 times stronger than raw domestic sewage. “A significant discharge of leachate into a watercourse can remove so much oxygen that fish and other aquatic life die immediately.” It is very important to keep silage leachate from reaching surface or ground water. We are all in this together, and should all care about our downstream neighbors, the domestic and wild animals and our future generations who will inherit the soils and waters we have used.
If you think your farm has a silage juice problem, there is always time to change it. Soil and Water Conservation District offices offer assistance with silage leachate management as a conservation practice. If you would like assistance with controlling silage leachate contact your local SWCD.