No Till Notes - "Cover Crops"

By Mark Watson, Panhandle No-Till Educator

The one thing I can say about this summer and the heat and drought that has set in is that I’m starting to look forward to January. I wouldn’t mind being cold again.

We finished up the winter wheat and field pea harvest about a week ago and are concentrating on making sure the irrigated crops are in good shape. The corn and pinto beans are moving along and look good if you can keep enough water on them. We have also drilled cover crops into our irrigated winter wheat stubble.

I’ve had mixed feelings about planting cover crops but we felt it was the right time to plant them again on our farm. As you may recall we have always left our irrigated winter wheat stubble intact and planted our corn directly into this heavy residue.

We tried cover crops a few years ago for grazing cattle and had good results, but didn’t think the economic benefit offset the water we used to irrigate the cover crops. The grazing of cattle left us with less residues the following spring which also increased our irrigation requirements on the corn the following year. We have really tried to conserve our groundwater, so we weren’t willing to trade groundwater for the benefit of the cover crops.

We decided to try cover crops again this year to manage our winter wheat stubble. We felt this heavy stubble with high carbon to nitrogen levels has slowed the development of the following corn crop. I don’t think it hurt our yields, but we thought we would try the cover crops to get the corn off to a better start next spring.

We are trying to keep a good amount of residue level in the field with the cover crops, but we are trying to change the high carbon low nitrogen level of the winter wheat residue and replace it with residue that has a higher level of nitrogen with less carbon. This should leave residue in the field which will be easier to plant into next year and an overall reduction in residue that should improve the early season development of our corn crop.

If this cover crop works out the way we think it will there will still be plenty of residue on the soil surface to lower our soil moisture evaporation rates next year and allow us to conserve our groundwater. We won’t graze these cover crops this time and leave the residue for the soil to lower soil moisture evaporation rates next year.

With these cover crops we are also trying to produce nitrogen for the corn crop to utilize next growing season and lower our rates of commercial nitrogen fertilizer. We will have to conduct some on farm experiments during the growing season to see how much nitrogen benefit we can expect from these cover crops.

We are also trying to improve the overall health of our soil by planting these cover crops. I think it is very important over the long term to improve the organic matter content in the soil. We are going to try and improve our organic matter with the cover crops. We will accomplish the increased organic matter by providing the soil with additional residues and living roots under the soil surface.

I also think the overall health of the soil will improve due to the increase in soil microbes and their diversity in our soil. I’m not a soil microbiologist but I really think there is something to improving the environment for these microbes in the soil to thrive.

With these goals in mind of managing our winter wheat residue and changing the carbon/nitrogen levels in the residue, improving soil organic matter content, reducing commercial nitrogen requirements, and increasing the population and diversity of soil microbes we planted cover crops again this year. Next week I’ll explain what crops we planted and why we choose these cover crops for our mix.