Wet, dry years mitigated by grazing, cover practices
2020 will go down as one for the record books, and with all that’s occurred over the past 10 months, it would be no surprise the weather was just as wacky.
The first four months of the year we started out with above average precipitation, and then beginning in May, we flipped a switch and started to fall below average to the point we’re now about seven inches below normal, and depending on where you’re at in the county, it’s likely even more.
1988 has been the driest year on record over the past 40 years, but looking back through my records, there have been five or more years since 2000 that have been comparable as this year.
2013 was within half an inch of our current rainfall, and 2016 was just a few inches above. And when you factor in the rain we’re getting as I write this article, it will be even closer.
Unfortunately, we have a short memory when it comes to weather, and since the past three or four years have been extremely wet, we can forget what a less than normal year can look like.
This isn’t to diminish how impactful low rainfall can be on a farm but should remind us that while we can’t control the weather, we can control how the weather impacts the overall farm operation.
In pasture and hay fields, waiting a few extra weeks in the spring to turn cows out can have a huge impact on yields over the whole year.
Studies have shown that if we wait until a plant has reached the five-leaf stage and the first graze is taken back to the third leaf, annual yield is not impacted. If we graze that same plant back to a two-leaf stage, we lose over half of our annual yield.
Think about that. Overgrazing pasture the first graze of the year, even when we’re overrun with rain, can have a long-term impact, and in years like this, that yield impact is exacerbated.
The same thing can happen on crop fields, any time we till a field. Whether it’s a moldboard plow or a turbo-till, we release carbon or the sponge that holds water in the soil, and when we switch to no-till, we only slow the release of carbon from the soil.
Crops need a large amount of carbon to grow. That demand can’t come from air alone and it’s pulled from the soil, so while no-till is good, you’re not building carbon fast enough to keep up with the plant’s demand.
That’s why adding cover crops into a rotation has such a large impact.
In no-till corn and beans, we typically see infiltration rates of one inch per hour. When we add just rye or wheat to that rotation as a cover crop, we double the infiltration rate, and the longer we grow the cover the more impact we have on the soil.
When we allow the cover to grow to near pollination, we can hold a tremendous amount of water. We then plant into that cover. Rolling that cover down, we’re not only slowly releasing that stored water back into the growing crop. In June and July, when we need it, it’s available to the plant.
Not only that. By rolling that cover down, we’re armoring the soil and holding the moisture in the soil, doubling the water available to our growing crop.
Whether we have an extremely wet year or are suffering through a drought, cover crops and adaptive grazing can have a huge impact overall farm economics.
Feel free to contact our office to discuss how these practices can have a positive impact on your farm.
Andy Gaver is a conservationist with the USDA Natural Resources Conservation Service in Butler County.