This fall, a Newport area resident contacted the Washington Conservation District (WCD) office to ask for advice about deer. Staff here receive frequent complaints about the local deer, which have voracious appetites and appear to reproduce easily. This resident posed a new question. Do overabundant deer have any impact on nearby streams and waterways?
I considered this question while walking my dog in the park that evening. It was already early October and yet the weather was sunny, warm and very dry, with a hunters’ moon overhead. I had timed our walk so that I could watch the sun set on our way out and the moon rise on our way back. While walking, I thought about deer.
I grew up in a rural part of Washington County that has now become urbanized. Seeing a deer, as a child, was in fact quite a site to see. Once, one ran through the neighbor’s hay field, across the road and then across the lake on honeycomb ice. All the neighbors talked about the deer that we saw cross the lake on thin ice that day. Today, I still live in the house I grew up in, but I now have an eight-foot fence around my garden to keep the deer out. If I want to see a deer, all I have to do is look out the back window, stand on the porch, or look at the bird feeder during the winter.
Later that night, as I was lying in bed, I could hear a combine in a nearby field. When farmers comb the fields of soybeans and corn in the fall, we can see the damage done by the summer rains. Some parts of the county got over ten inches of rain this July. Driving past some of the bean fields that have been combined, one can see rill erosion, or small gullies that formed. Imagine the surprise it must be when the combine hits one of those gullies!
Plant residue left behind after combing helps to break up rain hitting the ground and slow the flow of snow melt. Soybeans don’t leave much crop residue, however, so these fields are more prone to erosion. Corn, on the other hand, can leave more residue if a farmer uses conservation tillage practices. The goal of conservation tillage is to leave at least 30% of the ground covered in plant residue during the winter and after spring planting. Leaving this amount of residue with soy beans is more difficult, but still possible. Modern farming practices that don’t include conservation tillage plow everything under, however, so that there is hardly any residue left behind, even on corn fields. As a result, the soil is bare for long periods of time and more likely to erode.
Changes in farming practices and increasing deer populations are two signs of the times here in Washington County. While there is no direct connection between the two, we do see more deer in the fall when the combines are running and the herds are on the move looking for food. Unfortunately, eroding streambanks and green lakes have also become signs of the times, due to an increase in runoff from farm fields, as well as commercial and residential development in the county.
There is not much we can do to limit the number of deer in our area, although local communities recommend against feeding them in our yards because it contributes to nuisance populations in residential areas and increased deer-car collisions. For farmers that are tired of watching their soil wash away from their fields, the Conservation District offers funding and technical assistance to help keep that from happening. There are financial incentives for farmers who switch to conservation tillage, as well as grants to install grassed waterways, fence livestock out of wetlands or repair eroding gullies.
To learn more about assistance for agricultural producers and schedule a site visit with a WCD staff person, call 651-275-1136 or visit www.mnwcd.org.
Guest Writer: Wendy Griffin is a Natural Resource Specialist with the Washington Conservation District. She can be reached at firstname.lastname@example.org or 651-275-1136 x.24.