Follow along with this narrative: Installing conservation practices reduces in-field erosion. Reduced in-field erosion decreases the amount of sediment carried in a stream. Streams carrying less sediment have more energy. Streams with more energy result in additional streambank erosion. Added streambank erosion increases the sediment load in the stream. Ultimately the sediment load carried in the stream remains unchanged. In the end, applying upland conservation only shifts the source of the sediment load from upland erosion to streambank erosion. Logically then, why should farmers install conservation practices if reducing upland erosion doesn’t result in less sediment carried in the stream?
Are you joking? You cannot be serious. The first time I heard this argument I was enraged. I could not imagine the perverted logic that conceived this thought process. What a twisted and warped way to look at the world. It was nothing more than an excuse for farmers.
”Introduce a little anarchy. Upset the established order…”
―The Joker – Heath Ledger
Several years have passed since I heard this argument. Reflecting now, I think the reason I was so outraged is because there is an element of truth in this logic that I did not want to admit. It made me rethink my established order…that any conservation would directly lead to clean water.
Agriculture has significantly changed the hydrology of our landscape. We have replaced forests with cropland. We have plowed under prairie to plant corn and soybeans. We have drained wetlands with tile and drainage ditches. We have straightened streams so they are easier to farm along. All this change in hydrology has reduced infiltration, increased runoff, and amplified the energy in our streams and rivers.
Studies have shown that conservation practices reduce upland erosion, but have led to increased streambank erosion, leaving the total sediment delivery unchanged. Wow, that seems like a waste of time and money.
But doing nothing isn’t the answer. Instead we should do more to modify the current hydrology in a good way. And there are really only three ways we can impact the hydrology enough to reduce runoff and significantly modify stream energy.
1. Replace cropland with permanent vegetation like grasslands and forests.
Permanent vegetation increases water infiltration, thereby reducing runoff. For obvious reasons, it is unlikely that farmers will voluntarily return a significant amount of row crop to permanent vegetation. The Conservation Reserve Program (CRP) has only gotten us so far. But every little bit helps.
2. Increase soil health by using no-till and/or cover crops.
Improved soil health leads to greater infiltration and less runoff. Soil health, in theory, is the best solution. However, soil health is not a permanent fix. Years of improved soil health generated by no-till can be undone in a few short years. For example when a super weed surfaces, like Palmer amaranth has, farmers may believe they need to use more aggressive tillage.
3. Retention structures like ponds and wetlands lessen runoff.
Installing more ponds and wetlands is the most effective and permanent solution to reducing stream energy. Ponds and wetlands even provide lots of secondary benefits. But they are expensive and time-consuming to engineer…up until now.
As I have said in earlier blogs, I don’t believe in silver bullets. In theory, any one of these solutions could succeed. But in reality, implementing only one approach will fail. We should never put all of our eggs in one basket. I suggest we promote all three options and keep our eyes wide open about the limitations of each one. Let’s avoid the twisted logic that concludes any conservation practice, wherever it lands, helps achieve our goal for cleaner water.
We need to support farmers by being honest with them about the benefits, as well as the limitations, of the what and where of conservation practices. Furthermore, we need to be honest about how and where we spend our precious conservation dollars. Doing more is not necessarily better – what I have often referred to as the shotgun approach. We need to be precise in our efforts to modify hydrology, or else all our efforts to reduce soil erosion will fall short of producing cleaner water. That is logical. And we can’t wait.
Voice your opinion. Please add to the dialogue by including your comments below. How do you suggest we introduce a little anarchy into the current strategies guiding what and where conservation practices belong?