Field Salad: A No-management Cover Crop to Move Practice Adoption Beyond Just the Innovator Farmer

Progress report for ONC19-057

Project Type: Partnership
Funds awarded in 2019: $29,740.00
Projected End Date: 10/01/2022
Grant Recipient: Prairie Rivers Network
Region: North Central
State: Illinois
Project Coordinator:
Catie Gregg
Prairie Rivers Network
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Project Information

Summary:

This project was developed after hearing a cover crop farmer at a local watershed meeting argue that no matter how many benefits cover crops have, the largest farmers will never use them because they have too many acres to do this amount of management.  Field salad completes its life-cycle almost completely outside of the corn and soybean growing season potentially removing the management barrier to using cover crops. 

This project will assess field salad’s ability to function as a cover crop in a corn and soybean rotation without additional management. Corn and soybean yields will be compared with and without a field salad cover crop under three different kinds of management (organic, no-till, and conventional).  Weed pressure under these different scenarios will also be measured.

Developing field salad as a cover crop has the potential to address all three of NCR-SARE’s goals.  It protects our natural resources by helping expand cover crop adoption beyond current levels. Field salad may improve the lives of farmers by making cover crops an option for farmers who are not normally involved in these kinds of conservation practices. Farm profitability could also be improved by decreasing the cost of using cover crops. 

Project Objectives:

Action Objectives: Determine whether field salad is compatible with organic, no-till and conventional cropping systems. In particular, can it re-establish itself, not negatively impact yield, provide additional soil cover, and does it offer any weed suppression.

Learning Objectives: Presentations on the study's results and farmer co-operator experiences will look to reach farmers who have not yet tried cover crops, especially those who thought cover crops involved too much management. Farmers attending these meetings will be asked to fill out a survey on their attitudes and experiences with cover crops and whether learning about field salad changes them.

Cooperators

Click linked name(s) to expand
  • Ed Karr (Researcher)
  • Rick Kerchenfaut (Researcher)
  • Will Glazik (Researcher)

Research

Materials and methods:

Year 1- 2019

To test how field salad grows in-field we used a randomized controlled block design comparing control plots to plots that have been seeded with field salad. The control plots used the farmer's normal farming practices. The treatment plots had the farmer's normal practices plus the field salad cover crop. This study was repeated on three farms with different cropping systems (conventional, no-till, and organic). There are 4 replicate pairs on each farm.

The plots are 100 feet square and were seeded with a hand seeder. We had initially planned for larger plots. However, with the record breaking wet spring in 2019 the fields were harvested late. Since the fields were not able to be seeded until November, we held back part of the seed in case the plots needed to be reseeded. The plots have all germinated, so the extra seed will be given out to farmers as part of our outreach at the end of the grant.

All of the fields in this study will be growing corn in 2020. The conventional and no-till fields grew soybeans last year. The organic farm grew a summer cover crop mix last year that was tilled in.

The plot layouts can be seen here - Randomized controlled block plot design

Residue

Residue measurements were taken in February using the line-transect method. A 50 foot measuring tape was laid on a diagonal across each plot and at each foot marker it was recorded as either touching or not touching some sort of ground cover. Only one side of the tape was used to measure residue. These measurements were then converted to a percent coverage.

In the spring, 2 foot square quadrats will be used to measure the field salad's biomass. In the fall, larger 3 foot square quadrats will be used to compare the yields of the control verse treatment plots.

Year 2- 2020

Spring biomass

Spring of 2020 biomass samples were taken from our no-till and organic fields using a quadrat. While there had been some seedlings on the conventional field when we measured residue over the winter, there were no field salad plants in the field come spring. The larger samples from the organic field were dried at the U of I dryer prior to weighing. The smaller samples from the no-till field were dried in a microwave.

Yield

In the fall, we took yield samples from our no-till corn field by harvesting four 17’ 5” samples of corn from each plot to be combined into one sample. The sample weigh was taken, and then a 1/10th subsample was brought back to the university for threshing. The weight of the whole sample was then extrapolated from the subsample. Details of our harvesting and calculations can be found in the following document Yield Sampling Methods. We had planned to use similar methods on our soybean field. Unfortunately, at the last minute that field was accidentally harvested prior to our measurements. 

Reseeding

Field salad was reseeded in the no-till and conventional till fields in the fall of 2020, New plots fall 2020. Field salad in the conventional field germinated, but then died. In the No-till field, it grew, but was sprayed before it could mature and produce seed. The spring of 2020 was very cool, which appears to have delayed maturity. The soybeans in the organic field were not planted until after the field salad had matured. Although the field salad plants were smaller than in other fields, they were able to produce seed. This field was tilled before planting. However, field salad was able to successfully reseed itself in the fall of 2020 and these plants are seen growing in the spring.

Residue

Residue measurements were taken in the fall using the same methodology as the previous year, using a 50 ft measuring tape. 

 

 

Research results and discussion:

Year 1- 2019

One of the benefits of field salad is that despite a wet season pushing harvest back significantly we were still able to get the cover crop to germinate in the fall. As expected, it has mainly stayed at a seedling stage in this first season. In future years, when the cover crop has more time to establish in the fall, we anticipate it producing greater over winter cover.

With the weather cycling between 50 degree days and snow storms it was difficult to find days where the soil was firm enough to go into the field but where there was not snow or ice on the ground. The fields were mostly clear of ice and snow on the day we took our measurements. However, three of the plots on the organic farm had ponding and ice covering a significant portion and so we were not able to get measurements for those plots. Again, because the cover crop was still in the seedling stage, we did not expect to see significant differences in soil coverage between the control and treatment plots.

Residue

The conventional fields had more residue than expected with their high levels of tillage. Interestingly, most of the residue was from corn, even though the previous crop was soybeans. Discussions with the farmer revealed that he had been having difficulty with his residue not breaking down. The organic farm had tilled in a summer cover crop mix and seeded a winter cover crop mix of cereal rye, brassicas, and clover. There was a mixture of the tilled cover crop residue and the winter cover crop in the field. There were also traces of corn residue. The no-till field had a thick thatch of soybean stubble covering the entire field. The field salad seedlings seemed to grow better in fields with higher residue. It was often found under clusters of crop residue or at the base of the other cover crops. 

The residue levels between treatment and control plots were comparable, with the conventional field having the greatest in-field variation. The conventional field had an average of 67% and 63% cover on the control and treatment plots respectively. The no-till field had a full cover across the field with an average of 100% on the control fields and 99% on the treatment fields. The organic fields had an average of 91% on the control plots and 92% on the treatment fields. 

The individual residue measurements can be seen here - Residue- 2_11_20

Year 2 -2020

Biomass

The average biomass samples for the no-till field were greater for the treatment group with 35g, vs. 27g for the control group, see No-till Biomass-2020. One of the plots in the control group had significantly more biomass, mostly due to grass weeds, than the other plots and may be skewing the results. When this plot was removed the remaining control plots had an average biomass of 39g which is closer to the treatment group. In the organic field, the control plots had higher biomass than the treatment group, with 539g and 496g respectively, see Organic biomass 2020. The organic fields were also seeded with a cover crop mix that included cereal rye. This accounts for the much higher biomass weights seen in this field.

While the field salad in the conventional field died, there were a few field salad plants on the edge of the field. Interestingly, these were larger and more mature than the plants on the no-till or organic fields.

Yield

In the 2020 growing season field salad did not grow on the conventional field, and the main crop was accidentally harvested early on the organic field. The average yield was not substantially different, with the control having an average of 246 bu/ acre and the treatment having an average of 241 bu/acre corn, see No-till yield data 2020.

Reseeding

In the organic field, field salad was able to reseed itself. This is despite having heavy competition from the cereal rye that was also planted. The field salad plants were small, but they were still able to mature and produce seed. Being buried with tillage did not prevent field salad seeds from germinating the next year. Since the conventional and no-till fields had to be reseeded, we took the opportunity to reorient the plots to make them easier to harvest yield data in the future. 

Residue

The conventional and no-till corn fields had residue levels in the 90’s for both the control and treatment plots. The organic soybean plots had slightly lower residue levels of 85% for the control and 77% for the treatment. These lower levels are attributable to soybeans producing less residue than corn. Residue values can be found here, Residue-Fall 2020.

 

 

Participation Summary
4 Farmers participating in research

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

We are still conducting the research phase of our project and therefore have not engaged in any outreach activities about our results.

Learning Outcomes

Key changes:
  • While 4 farmers are involved in the project, we are still conducting the research phase of our project and therefore have not engaged in any outreach activities about our results.

Project Outcomes

Project outcomes:

We are still conducting the research phase of our project and therefore have not engaged in any outreach activities about our results.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.