Managing Prevent Plant Acres
Jun 17, 2019
Now that the planters and air seeders are parked from planting cash crops, it’s time to start looking at a plan to manage the soils that did not get planted this spring. Below are a few guidelines to help get this soil ready for next year!
- DO NOT LEAVE IT IDLE
Leaving soils with nothing growing on them is not an option! The days of cultivating several times during the summer or using herbicides to control weeds are long gone. These practices would create issues not just for next year but potentially for years to come.
First off, let’s look at tillage. There are several things multiple tillage passes do that are not good for the soil. Every tillage pass initiates evaporation of water which will then bring more salts from the lower soil profile to the top. This wicking up of salts works the same as water moving up the sheetrock when your basement gets wet. The movement of salts into the upper profile will limit crop growth next year and potentially beyond.
The second thing that happens with multiple tillage passes is that the soil aggregates and pore spaces get destroyed. These aggregates and pore spaces are needed for two major functions of the soil. The first is they provide space for water to move down through the profile and leach salts out of the root zone. The second is these spaces provide room for oxygen in the soil. This is essential to keeping soil microbes and plant roots healthy.
The third important thing that happens when multiple cultivations occur is the accumulation of water in the soil profile (remember summer fallow days). Plants growing will use up far more water than can ever evaporate off a field.
The use of multiple herbicide passes during the summer to control weeds has two draw backs. The first is that it will be expensive. The second is that the use of herbicides in this way will continue to build resistance in weed populations. So, to keep your herbicides working for years to come, try to use as few applications as possible. The best way to limit herbicide is to plant a cover crop that will shade out weeds!
- PLANT A COVER CROP
Cover crops are a key piece to managing soils that have not been planted. Cover crops carry out several important functions to help get these soils ready for planting next spring.
The first is that cover crops use water. These cover crops will use excess water the entire time they are growing. As these cover crops dry out the top portions of soil profile, they allow for summer rains to move down through the soil profile rather than running off. These summer rains moving through the profile will help leach salts out of the top portion of the soil.
The second thing cover crops do is provide roots for beneficial soil microbes to live on. Of these microbes, one of the most important is mycorrhiza fungi. These fungi colonize on plant roots and help the plant pull both water and phosphorus from the soil. When tillage is done or no living plant roots are in the soil, these fungi start to die off and will take time to recover once there are living plant roots present. Many times, the year following a fallow year we will see fallow syndrome in grass crops which is caused by the lack of mycorrhiza fungi. Also, living plant roots will help keep the other beneficial microbes in the soil healthy and living. These microbes aid in breaking down organic matter into the nutrients our crops use.
The third important thing that cover crops do for soils is they provide protection from wind and water erosion. The growing plants will intercept rainfall before it hits the ground, helping limit soil from breaking apart and running off. The growing plants will also keep the wind from blowing soil off the field.
The fourth and probably one of the most easily seen benefits of cover crops is that they keep weeds from growing. The canopy provided by the cover crop will keep weeds such as kochia, common ragweed, and waterhemp from emerging and going to seed. Keeping weeds under control and from going to seed will pay huge dividends not just for next year but for years to come.
- MANAGE COVER CROPS
Make sure to manage cover crops to achieve your goals for the soil. Here are things to consider that will ensure your cover crops are working for you.
- What will your 2020 crop be? To help keep disease and insects from affecting next year’s crop, don’t use the same species this year that you plan to plant next year. Also, try to pick cover crops that will benefit next year’s crop (i.e. plant a legume species if you plan to plant a grass crop next year).
- What do you need to do in your fields with cover crops? If you need to break up compaction in your fields be sure to include radish in the mix you plant. If you are looking to use up as much water as possible, plant a high-water use species such as sunflower. If you are looking to build more soil aggregates, try to include a small grain species.
- How much is in your budget for cover crop seed? Set a budget and stick to it. You do not need to use a 20 species cocktail mix that costs $50/ac to get the benefit of a cover crop. Use seed that you have on farm already or seeds you can buy for cheap. Try to use 3-4 species and not spend more than $20/ac on the seed.
- Kill the cover crop if needed. If there are species in your mix that are close to going to seed and you don’t want them to, don’t be afraid to use a chemical application to take that species out.
These are just a few quick guidelines to help you succeed in preparing your soils for next year. To help you get the exact results you are looking for, be sure to visit with your ACI agronomist. Thanks for your business, and we look forward to helping you get ready for 2020!