Keeping your fields green will keep Lake Erie blue and your farm in the black

Impacts in your field

                Above ground, cover crops protect your field from the impact of raindrops.  When a leaf absorbs the energy of a hard rain, the soil particles underneath are less likely to be knocked loose or compacted.  The green part of a cover crop (even after it turns brown) also slows down the wind near the ground, reducing wind erosion in dry soils. 

                But the real work of a cover crop happens in the soil.  As the cover crop germinates, the roots move through either existing root channels from the last crop, or through other small spaces, widening them and holding them open.  These vertical channels help move air, water, and nutrients deeper into the soil, exactly where your next crop needs them to be.  Once the cover crop is dead, the decaying roots add to the soil’s organic content.  A healthy cover crop can out-compete weeds, reducing herbicide needs.  Some cover crops, such as clover, vetch, or winter pea, can also boost nitrogen availability in soil, reducing the need for fertilizer the next year.  If you are at the Wood County Fair, make sure to find the SWCD display in the Grange.  We have been growing cover crop samples in clear tubes so you can see what is going on underground when you have a cover crop on your field.  Spoiler alert: our tubes were not tall enough!

Effects in your watershed

                Cover crops are also important for water quality.  No matter how far inland you are, your fields are still part of a watershed.  This means that soil or nutrients lost to erosion, runoff, or tile lines will end up in a river or lake downstream.  All of Wood County drains to Lake Erie, either through the Maumee, Portage, Sandusky, or Toussaint rivers, or unnamed smaller streams which flow directly to the lake.  (Stop by our display in the Grange Building at the Wood County Fair to find out what watershed you live in.)  The source of water quality problems in Lake Erie is often miles upstream, and Lake Erie will continue to have algae blooms, anoxic zones, and fewer fishing and recreational opportunities as long as polluted water is flowing into it.  By using cover crops to hold nutrients and soil in your field, you are keeping the sediment and nutrients from creating a problem elsewhere. 

MODIS satellite imagery from 7/12/13 shows sediment (and nutrients) entering the lake from multiple rivers

The bottom line

                Ultimately, choosing to add a cover crop to your plan is a financial decision.  The expense of buying the seed and (perhaps) taking the extra pass through the field has to be offset by improved soil quality, higher yields, or reduced fertilizer costs.  There isn’t one blanket recommendation for what cover crop or blend of cover crops to use – each farmer needs to assess the conditions in each field to decide what is the most beneficial to that field.  However, there is plenty of information available on the advantages of different types of cover crops, and the benefits they provide to soil, water, and profits.

A good place to start your research is here: http://www.hort.purdue.edu/tristate_organic/cover_crops_fert_2007/1-covercropfundamentals.pdf  Or stop by the Wood SWCD display during the Wood County Fair.  We are in the Grange this year.