No Till Notes: 'Moving forward'

The past few weeks I’ve been looking at the possibilities of improving the health of the soils we work with here in western Nebraska. The soils we work with have lost organic matter, soil microbial populations and diversity as well as soil structure over the years with our crop production practices.

To begin to restore soil health, the remedies seem pretty simple but can be hard to implement. When I’ve listened to presentations by experts on the remedies for restoring soil health, there are common threads throughout each presentation. Some of the keys to restoring soil health are keeping the soil covered with previous crop’s residues, adopting no-till crop production practices, diverse cropping rotations and having a living root growing in the soil for as much as possible during the growing season.

We began traveling down the path to soil health 20 plus years ago when we adopted no-till crop production practices on our farm. At the time soil health wasn’t on our radar, we were simply trying to utilize our resources and make our farm more profitable. Over the years we have definitely seen our soils respond and change in their physical properties. Our soil has a different feel to it than neighboring soils where winter wheat/ summer fallow practices are used with conventional tillage practices.

I feel our soil has improved in performance over time. We have improved the soil’s organic matter content during this time. I am certain we have improved the water infiltration and water holding capacity of our soil. Through testing we have shown we also have improved the soil microbiology in our soil with increased diversity and populations of soil microbes. I think our soil mineralizes nutrients more readily making them available to the plants we grow.

With our no-till cropping system we have adopted many of the principles needed to improve soil health. We have a diverse cropping rotation with warm season grasses and legumes. We leave the previous crop’s residues on the soil surface. The one area in improving soil health that we are lacking is having a living root growing in the soil throughout the growing season.

Extending the time in which we have a living root growing in our soil with increased plant biomass on the soil surface is the one component of improving soil health that is more of a challenge in our environment. The cash crops we grow have a living root growing in the soil for a limited time during the full growing season. Much of the time during fallow periods between crops we don’t have anything growing in the soil. In terms of soil health this is a concern.

Cover crops have been shown to be beneficial in improving soil health by extending the time living roots are grown in the soil. I define a cover crop as a crop which is planted following a cash crop harvest or prior to growing a cash crop. A cover crop is grown solely for the purpose of improving the health of the soil and/or to scavenge nutrients which may otherwise leach through the soil profile.

Cover crops have been grown quite successfully in areas following winter wheat harvest where they normally receive ample precipitation after wheat harvest to establish and grow the cover crop. The problem I see with this use of cover crops in our area following winter wheat harvest is the lack of reliable precipitation and the relatively short growing season remaining following our winter wheat harvest.

My concern with cover crops behind winter wheat harvest is our ability to replace the residues by growing the cover crop that we will lose by drilling the cover crop following harvest. Maintaining good residue cover is essential in our environment and I feel we would typically experience a loss of total residues in the field by planting cover crops following our winter wheat harvest.

My other concern is making the cover crops cash flow. The benefits of improving the soil’s health may take several years and the expense of raising cover crops during this time may prove to be economically challenging. I have no doubt that adding a living root growing in the soil during the entire length of the growing season would be beneficial, I just haven’t figured out how to do it.

Next week we’ll look at more options to adding a living root growing in our soil for an extended amount of time to improve soil health.