Although producers are tried their hardest to get as much planted as possible this spring, there are fields and especially areas of many fields that were simply too wet to get seeded this spring that will fall under the classification of prevented planting acres. The question is what to do with these acres.
The best option would be to plant a cover crop or annual forage crop on these acres later this summer if they dry out enough to seed. Having desirable plants growing in these areas will help dry the soil down as the plants use the moisture and transpire moisture through their leaves.
Drying soil down with plants is better than relying on evaporation to dry the soil out. One of the big advantages to using plants to dry the soil down is if there are any salts in the soil profile, they will stay where they are as opposed to being brought to the surface where salts will be deposited and concentrated as the moisture evaporates. As we saw during the wet years starting in 2011, the concentration of salts left on the surface as moisture evaporates can lead to expansion of saline areas or the development of new saline seeps.
In addition, having plants growing and living roots in the soil is beneficial to soil health. Living roots support the soil microbes and between them, they help improve soil structure.
Cover crops also provide the opportunity to add more diversity to the cropping system, which is another one of the soil health principles, however, having a living root in the ground is probably more important even if it is just a single species or simple mix to use excessive moisture and provide soil cover.
In case you haven’t seen it, the following is a good article on Cover Crop Options for 2022 prevented plant acres which just came out in the latest issue of the NDSU Crop & Pest Report:
COVER CROP OPTIONS FOR 2022 PREVENTED PLANT ACRES – Despite high crop prices, some acres in North Dakota may still be prevent planted during the 2022 growing season. It is essential to establish covers in 2022, at least to use excess soil moisture, otherwise, there will be a high chance of 2022 prevent plant acres going into prevent plant again in 2023. In addition, cover crops can be used for grazing, haying, baleage, preventing erosion, adding plant and microbial diversity, and keeping soils healthy and productive. Like any other decision, selection of cover crops, whether a single species or a species mix, should meet the objectives of the landowners or producers. Premixes may serve some purposes, but they might not meet all. Custom mixes are better suited for farm specific or, even better, field specific objectives.
Here are some potential questions one should ask to finalize a cover crop mix:
1) Is the field affected by excess levels of water-soluble salts and/or sodicity?
2) What will be the next crop on the field where cover crop is going to be planted in 2022, to consider and avoid volunteer issues?
3) What could be the herbicide and weed considerations?
4) Are there any disease considerations?
5) Is grazing an option?
6) Is haying or baleage an option?
7) Do the objectives include a species that over-winters and greens-up in 2023?
8) Do we just want a cover to use excess moisture this year or would we like to increase organic matter, stimulate biology, and improve fertility?
9) Do the objectives include attracting pollinators?
10) What is the maximum cost per acre we are willing to pay for seed and planting?
11) What is the plan for managing crop residue or plant biomass in case of no grazing, haying, and baleage?
And there could be other considerations as well.
Given below are some of the most common scenarios and cover crop choices without any specific considerations:
A Single species to Use Excess Soil Water and Provide Soil Cover – If planted immediately after the “final planting date”, sorghum, sorghum Sudangrass or a millet would be good options for producing maximum biomass, as these are warm-season species. Stand-alone seeding rates could be 25 to 30 pounds per acre. Another option could be stand-alone oats and barley or a mix of them for providing an effective cover. Seeding rate for stand-alone barley or oats could be 40 to 60 pounds per acre, whereas, in case of a mix, it could be 50% barley with 50% oats (20 to 30 pounds of barley and oats).
A Three-species Mix to Achieve Multiple Objectives – A simple mix could be comprised of a warm-season, cool-season, and a legume. Examples could include sorghum, barley, and field peas. Seeding rates could be 2 pounds or less of sorghum, 15 to 20 pounds of barley and 20 pounds of field peas. If grazing is an option, forage sorghum can be planted with forage barley and forage peas. Seeding rates will remain the same. Another example could be sorghum, radish, and field peas. Seeding rates could be 2 pounds or less of sorghum, 3 pounds per acre of radish and 20 pounds of field peas.
Another Three-species Mix That Can Achieve Multiple Objectives – A mix of barley or oats combined with radish or turnips and chickling vetch can also help improve soil health, use excess moisture, and prevent erosion. Seeding rates could be 20 pounds of barley or oats, 1.65 pounds of radish or 1 pound of turnips and about 6 pounds of chickling vetch. Please note that areas affected by Clubroot should avoid brassicas.
A Three-species Mix for Moderately Saline and Sodic Areas – A mix of barley, oats, and beets can work well on areas that have soil saturated paste electrical conductivity or EC levels of 6.00 (dS/m) or less and a sodium adsorption ratio or SAR of 7.00 or less. Please note that beets do not compete well with other species, so beet percentage in the mix should be 40 to 50%. That will mean 1.4 to 1.5 pounds of beets combined with 15 to 18 pounds of barley and oats.
NDSU Extension has a publication of how to start growing cover crops in North Dakota (North Dakota Cover Crop Recipe – Starting with Cover Crops in North Dakota – MCCC (msu.edu)). Information about the basics, functions, and goals of cover crops can be found in this publication.
NDSU Soil Health website has a great tool called Searchie for quickly getting information on cover crops for prevent plant. Just follow the steps below:
1) Click on this link: https://www.ndsu.edu/soilhealth/searchie/
2) Type in “prevented plant”
3) The search tool will show you where we talk about this topic in videos and podcast episodes. When you click on the link, it will take you directly to the relevant information mentioned in the video or the podcast
Also, NDSU Extension has a 2022 Prevented Planting Analysis Tool, which can be found on this link: https://www.ndsu.edu/agriculture/ag-hub/ag-topics/crop-production/tools/2022-prevented-planting-analysis-tool
For advice about specific cover crop mixes, please contact your local Agriculture and Natural Resources Extension County agents.
This article was authored by Leandro Bortolon, Extension Cropping Systems Specialist; Abbey Wick, Extension Soil Health Specialist and Naeem Kalwar, Extension Soil Health Specialist.
Williams County Soil Conservation District 