In 2013 and 2014, VanTilburg Farms Inc. seeded 3 corn and 3 soybean fields to cover crops using cocktail mixes of at least 8 different species of cover crop seeds. The mixes were made up from 26 different species to make up 13 different seed mixes. These were all seeded in growing corn at tasseling and in growing beans, just before turning yellow. The same fields were used both years and were seeded the same each year: corn was planted one year and beans the next.
2013 was a very dry summer and planting was done in mid-August for corn and first week of September for beans. Results were poor, as the first sufficient rain was not until September 20. An early cold snap terminated the winter kill species early.
2014 was a very good growing season with corn tasseling in mid-July and beans growing into mid-September. Two of the three corn fields were seeded before tasseling and the third, right after tasseling. Soybeans were seeded in mid-September in an excellent stand of still green beans. Soybeans were late maturing due to plentiful moisture.
Adequate research and information is available on multi species cover crop mixes planted after wheat harvest. Many species mixes have been used after wheat. The amount of field-based research available for multi-species (8 or more) mixes for use in a strictly corn/soybean rotation is limited. Planting cover crops after corn and soybean harvests, limits the species of cover crops that can be planted that late in the fall. At present, most of the cover crops seeded are: clover, annual rye grass, cereal rye grass or tillage radishes after harvest. By planting in growing corn and soybeans in mid to late August, the mix of species is expanded and improves the mix of species growing year round to improve soil health and tilth. Cover crop mixes after corn and beans with 8 to 12 species have not been reported. This could be accomplished by using either aerial seeding or seeding by using a highboy designed to seed cover crops in growing corn and beans.
The design of this project is to use a highboy seeder to seed 3 different cover crop mixes in 3 different corn and bean fields in 2013 and repeat in 2014 in the same fields. This would provide 2 years of data using different species mixes in corn going to beans and beans going to corn. Each field would be approximately 40 acres making this a field-sized demonstration. The 3 farms would exhibit different management practices and fertility.
Many cover croppers promote the value of a cocktail mix of 8-10 species drilled after wheat. The design of this project was to see if the same benefits could be achieved by using VTF’S highboy seeder in growing corn and beans to get a similar benefit from the mixes. Forty acre fields were seeded with 3 different mixes, using a cover crop seeder designed and built by VTF. Some questions to be answered were the following. With 8 different seeds and different seed size, could even seed distribution be achieved across the field? What species would grow being dropped on top of ground? How early could cover crops be seeded in corn and sprout without dying due to lack of sunlight? How much additional growth could be achieved as compared to seeding with a drill after harvest?
Three farmers provided a bean and a corn field for the project. The crop rotation is corn and beans so that the same mixes were planted in the same plots each year. One year of corn, and one year beans. Three different mixes were spread on 3 plots of corn and 3 plots of beans, replicated 3 times in each field each year. The plots were planted the same each year. Some plots were designed to winter kill and some were designed to be sprayed and killed in spring before planting.
Cover crop mixes attached:
2013 was a dry summer, without rain until mid-September; this means the species did not get off to a good start. Plots were surveyed March 20 and 27, 2014 and growth was scarce due to the dry fall, rough start and severe winter weather. Winter kill was very evident in all plots. The knowledge gained was the corn plots could be seeded even earlier. The goal for the 2014 year is to seed some cover crop prior to tasseling and the rest around August 1. The bean fields were mostly affected by the dry fall at seeding and did not have growth as expected.
2014 was a good growing year and corn plots were seeded in early July before two of the fields tasseled, and just after tasseling on the third field. Rain followed soon and germination was good in early August. It was evident that there was very poor germination of the large seeds such as sunflowers and to our surprise, there was also poor germination of buckwheat. Cow peas, sun hemp and flax were rated as poor. The rest of the species showed good to excellent stands across the plots.
Harvest 2014 was wet and late and cover crops showed the stress from lack of light and harvesting in wet fields. November 9th, temperatures dropped to 28F and on the 24th 15F was recorded, killing most growth. Since then it was a cold winter, without much snow cover.
It will be interesting to see how the rye grass, wheat, and vetch survive. They all showed good growth and vigor at harvest. Most cereal grasses, legumes, and Brassicas did well on a majority of the plots in 2014. Rape and Ethiopian cabbage were not as dense as radishes and turnips. Sun hemp sprouted, but did not grow. Peas, cow and winter, were thin and only did well in areas of very thin stands of corn and beans.
Mixtures of any 3 or 4 grasses, oil seed radishes, purple top turnips and clovers, vetch and non GMO beans – gave satisfactory stands. These seemed to do well in both mixes designed to winter kill, as well as mixes designed to still be growing in the spring.
A late winter and very cold wet and snowy March spelled no growth and almost no green up, yet on March 26, 2015. Thus at the time this report is due not much can be said for what survived the winter as of right now it is mostly bare ground showing.
Impact of Results/Outcomes
Two plots tours were scheduled with disappointing results, with five showing up in Indiana and seven at the tour in Ohio. A late harvest was part of the problem. The best education took place when people were invited on a one-on-one basis to meet with us at one of the plots. Three newsletters were sent to local farmers describing the plots and inviting them to visit them any time. After harvest, signs indicating what species were planted were placed on all plots. Two of the plots had very good exposure on major highways.
Mixtures of any the grasses, oil seed radishes, purple top turnips and clovers, vetch and non GMO beans gave satisfactory stands. Mixes always had something growing well in our plots; it may have been only one species but something was growing. Recommendation would be to mix from 2 to 4 grasses with a brassica and 2-3 legumes. Use several criteria to develop your mix;
1. Does one want the mix to winter kill.
2. The cost of mix.
3. Date of planting.
- Multi-species cover crops have the advantage of not having a failure as something always germinated and grew.
- The small seeded crops like the Brassicas did better than the larger seeds like sunflowers, when seeded in growing crops without incorporation of some sort. All the grasses seemed to grow well when seeded in standing crops.
- Cocktail mixes have an advantage especially in fields that have never had cover crops before and would recommend that be used for first time use in new fields. They can be all winter kill, or a mix of winter kill and crops that need to be killed in spring.
- Would recommend avoid using large seeded crops and very expensive seed if flying or using a high boy to seed the crops. These crops did very poorly in all of the trials.
Additional Evaluation Details
1. The following species did poorly or did not germinate at all, planting is not recommended through a high boy or aerial seeding; Pearl Mullet, Sunn hemp, Cowpeas, Sainfoin, Flax and sunflower.
Soybeans, Sorghum Sudan, Trictale, and Buckwheat were disappointing and at best we found very few plants after harvest. Buckwheat germinated quickly, but disappeared almost as fast.
The remainder of species planted all had both good and bad stands, which varied from field to field and also within a field. That is why we preferred the mixes, as something was always growing across the field.
2. No difference in yields could be determined across the plots. However, yields could only be checked the second year of trials as 2013 was a bad fall to plant cover crops in the area and stands were poor. 2014 was a good growing year as yields were uniformly superior across the area. 2015 will be a better year to check yields, as 2014 was a good year for cover crops and also the second year for cover crops in the test fields.
3. Grid soil tests were completed on the 2015 bean fields with no noticeable differences. All the fields had received 3 tons of poultry litter per acre after the previous bean crop.
4. Soil tilth did not change much, if any after only 2 years of cover crops. However, the amount of roots present in spring of 2015 was significant as compared to non cover crop fields on the same farm. Again, the first year there was very poor growth of the cover crops, due to fall weather.
5. Unable to make any good analysis of costs versus yields, as there was no significant difference across plots and there was inconsistency of first year cover crop growth.
When comparing VTF fields that have been in cover crops for 5 or more years to the test plots, it became very apparent that 2 years is not long enough to make a good comparison of cover crops versus no cover crops.
Important key factors learned throughout these studies are that radishes and ARG or Cereal Rye, could be successfully seeded into growing crops and 4 -6 way mixes are better than single crop or 2 way mixes.