Integrating Solar Corridors into Vermont Corn Silage Production Systems

Progress report for ONE21-386

Project Type: Partnership
Funds awarded in 2021: $28,797.00
Projected End Date: 12/31/2023
Grant Recipient: University of Vermont Extension
Region: Northeast
State: Vermont
Project Leader:
Dr. Heather Darby
University of Vermont Extension
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Project Information

Project Objectives:

This project seeks to develop Solar Corridor Systems that are feasible for corn silage production systems in Vermont. The successful Solar Corridor System will optimize cover crop benefits and maintain corn silage yield and quality.  To develop a successful Solar Corridor System we will develop research with the following objectives:

Objective 1: Evaluate the effect of corn row widths and corn population on silage yield/quality as well as cover crop biomass.

Objective 2: Evaluate the effect of corn row width on establishment and productivity of forage based cover crops corn.

Farmers will benefit from the results by learning more about how to adapt corn silage production systems to reap the numerous benefits of cover cropping. Dairy farmers in Vermont are currently harvesting cover crops as forage adding additional benefits to the practice. A successful Solar Corridor System may further help farmers reap the benefits of cover cropping and crop diversity.

Introduction:

Although substantial gains in cover crop acreage have been seen across the northeast, proper establishment of cover crops continues to be challenging for dairy operations which rely heavily on corn silage. To overcome barriers associated with a short growing season, farmers have focused on interseeding techniques to establish cover crops into cash crops, however, limited success has been observed primarily due to significant reductions in light infiltration through the corn canopy. One factor is the pressure to maximize yields which encourages planting corn silage at populations ranging from 32,000-40,000 plants per acre. This reduces the amount of sunlight available to an interseeded crop.

Farmers have demonstrated their desire to cover crop and ability to integrate new practices into their operations. However, research has focused largely on the cover crop itself and has neglected to acknowledge other factors in the system; farmers need strategies that encompass the entire production system in order to fully realize the benefits of cover cropping. In a recent SARE grant (LNE18-361), Darby and 30 farm partners evaluated corn variety selection, corn population, and interseed timing to increase light infiltration and improve cover crop establishment. Results still remain highly variable.

In 2019, Darby and local farmers began to research the impact of corn row spacing on establishment of interseeded cover crops. Cover crops interseed into corn planted in wide rows (60 versus 30 inches) had 100% increase in cover crop biomass but corn yields were suppressed 3 tons/acre. This strategy is referred to as a Solar Corridor System that integrates row crops with solid-seeded crops in broad strips. The broad strips (corridors) allow for more efficient capture of solar radiation by each crop. Solar corridors are a variation on intercropping and allows for the production of two or more cash crops or a cash crop with a cover crop (Deichman, 2009). This strategy may allow farmers to select cover crops that maximize nutrient cycling or increase forage production and help reduce farm costs, off-farm inputs, and improve cover crop adoption.
Overall, VT farmers were very positive and felt the practice deserved more attention and that tweaks to the row spacing and population might close the yield gap. In addition, it was unclear if the cover crop in the solar corridor could be further utilized for forage. It is plausible that a cover crop species may make up for lost corn yield by providing additional forage, nutrients, and other benefits that may reduce on-farm inputs. As an example, Wisconsin research showed that successful interseeding of alfalfa into corn improved overall forage yields in a corn/alfalfa rotation (Osterholz et al., 2020).

Research is needed to understand the advantages and disadvantages of various row arrangements for corn silage systems, which cover crops are most successful in these systems, and which cover crops can provide the most benefit (i.e additional forage). Solar corridors are a relatively new cover cropping strategy and the information provided through this research will be used to create effective strategies for implementation in corn silage production systems.

Cooperators

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  • Wayne Fiske - Producer
  • Roger Rainville - Producer
  • Lindsey Ruhl (Researcher)

Research

Materials and methods:

REPORT 2021

There is little to report as the project has just started. However, our team is working with farmer collaborators to inform them the project as funded and to work on plans for the 2022 field trials.

 

 

We propose that changes in corn silage production practices combined with cover crop species selection can improve the establishment and value of interseeded cover crops. These trials will evaluate a Solar Corridor System. This system is a modification to intercropping and allows a farmer to increase diversity in their field. The main feature of the Solar Corridor System is use of wide row widths that allows full exposure of tall crops such as corn to sunlight while integrating lower growing crops between the rows of corn. In the proposed Solar Corridor System, silage corn will be grown in wide rows (up to 60") and cover crops planted between the rows of corn (the corridor). The proposed trials will evaluate Solar Corridor Systems with the goal of optimizing corn and cover crop productivity.  Treatments will be evaluated in small plots with on-station trials and with an on-farm replicated strip trial.

Effect of corn row width and population on corn and cover crop productivity (2022, 2023)

Treatments: Treatments will include cover crops interseeded into corn rows with varying widths and populations. Corn row widths of  30”, 36”, 40”, and 60” will be evaluated at 28,000, 30,000, 32,000, 34,000, and 36,000 plants per acre.

Methods: The experimental design will be randomized complete block (RCB) with split plots and 4 replicates. Main plots will be row width and subplots corn population. A Monosem precision planter will be used to plant the corn silage. A cover crop mix consisting of annual ryegrass, tillage radish, and red clover will be seeded at 25 lbs/acre. Cover crops will be interseeded with a DuoSeed Cover Crop Inter-Seeder (Dawn Biologic, PA) at the V4 corn stage. Plots will include 4 rows of each treatment and 50 feet in length.

Data Collection and Analysis: Light infiltration into the corn canopy will be measured at seeding, R1.0 and R5.0 corn stages. Cover crop biomass/cover will be measured at harvest and 3-weeks after harvest using a 1-m2 quadrat and Canopeo measurements. (http://www.canopeoapp.com/). Corn plots will be harvested with a 2-row chopper modified to include a wagon equipped with weigh bars to measure yields. Samples will be taken to determine dry matter content and corn silage quality. Samples for forage analysis will be passed through a 1 mm screen and analyzed for forage quality components (crude protein, fiber concentrations, and digestible) at the UVM E.E. Cummings Crop Quality Laboratory (Burlington, VT). Analysis of variance and means separation will be used to analyze data.

Farmers that were involved with preliminary solar corridor studies felt that keeping plant populations equal among the row widths might close the yield gap. This experiment will determine at which row width and corn population will corn silage yield and cover crop biomass be optimized.

Effect of corn row width on establishment and productivity of forage based cover crops corn (2022, 2023)

Treatments: Treatments will include 5 forage based cover crops interseeded into corn rows with varying widths. Forage based cover crops will include winter rye, annual ryegrass/clover/brassica, alfalfa, red clover, and orchardgrass.  Corn row widths will be 30” or 60”.

Methods: The experimental design will be randomized complete block (RCB) with split plots and 4 replicates. Main plots will be row width and subplots will be cover crops. A Monosem precision planter will be used to plant the corn silage. Cover crops will be seeded at 25 lbs/acre except winter rye at 100 lbs/acre. Cover crops will be interseeded with a DuoSeed Cover Crop Inter-Seeder (Dawn Biologic, PA) at the V4 corn growth stage. Plots will include 4 rows of each treatment and 50 feet in length.

Data Collection and Analysis: Light infiltration into the corn canopy will be measured at seeding, R1.0 and R5.0 corn stages. Cover Crop biomass/cover will be measured at harvest, 3-weeks after harvest, and the following spring using 1-m2 quadrat and Canopeo measurements. Cover crop biomass will be clipped to ground height at 2 locations within each plot. Samples will be weighed, dried, and weighed again to determine dry matter yields. Corn plots will be harvested with a 2-row chopper modified to include a wagon equipped with weigh bars to measure yields. An approximate 1-kg of corn silage will be sampled to determine dry matter and quality.  Soil nitrate-N samples will be collected at the 6th leaf stage to evaluate corn nitrogen needs. Samples of corn and cover crop treatments for forage analysis will be passed through a 1 mm screen and analyzed for forage quality components (crude protein, fiber concentrations, and digestible) at the UVM E.E. Cummings Crop Quality Laboratory (Burlington, VT).  Soil samples to determine the impact of the cover crop on soil health will be taken in the fall of each year. Soil health indicators including aggregate stability, active carbon and respiration will be measured through the Cornell Soil Health Laboratory. ANOVA and means separation will be used to analyze data.

Farmers that were involved with preliminary solar corridor studies felt that a perennial forage could be established in between the wide rows. This would allow for new forage seedings to be established during the corn year and hence increasing perennial forage yields during their first year of production. This would increase return per acre and value to the farm.

On-Farm Solar Corridor Trial

The collaborating farm will conduct trials in 2022 and 2023 to evaluate the impact of corn row width, on cover crop establishment and productivity.

Treatments: Treatments for the on-farm trial include comparing establishment of red clover with orchardgrass in 30” or 60” corn rows.

Methods: The experiments will be planted in randomized strip plots with a minimum of 3 replicates. Corn will be planted in May at 30,000 seeds per acre. The collaborating farmer will use their planters and remove row units to accomplish 60” rows. Cover crops will be seeded at 25 lbs/acre. Cover crops will be interseeded with a DuoSeed Cover Crop Inter-Seeder (Dawn Biologic, PA) at the V4 corn growth stage. Plots will include 12 rows of each treatment the length of the field .

Data collection: Light infiltration into the corn canopy will be measured at seeding, R1.0 and R5.0 corn stages. Cover Crop biomass/cover will be measured at harvest, 3-weeks after harvest, and the following spring using 1-m2 quadrat and Canopeo measurements. Cover crop biomass will be clipped to ground height at 2 locations within each plot. Samples will be weighed, dried, and weighed again to determine dry matter yields. Corn yield and quality measured by harvesting multiple plots (1/1000th of a row) and sub sampling for quality. Samples of corn and cover crop treatments for forage analysis will be passed through a 1 mm screen and analyzed for forage quality components (crude protein, fiber concentrations, and digestible) at the UVM E.E. Cummings Crop Quality Laboratory (Burlington, VT).  Soil samples to determine the impact of the cover crop on soil health will be taken in the fall of each year. Soil health indicators including aggregate stability, active carbon and respiration will be measured through the Cornell Soil Health Laboratory. ANOVA and means separation will be used to analyze data.

Research results and discussion:

We are just in the initial stages of the project and working with farmers to select fields and treatments for the on-farm studies. An initial project meeting was held with each collaborating farm in December of 2021.

 

Participation Summary
4 Farmers participating in research

Education & Outreach Activities and Participation Summary

2 Consultations
1 Webinars / talks / presentations

Participation Summary:

2 Farmers participated
56 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

From September to December of 2021 one presentation was provided to the Northeast Certified Crop Advisors focused on developing Solar Corridor Systems in Corn Silage. The presentation (webinar) was on December 15th and there were 56 attendees.

A presentation is planned for the Northeast Cover Crop Council Annual Meeting to be held on March 10th and 11th, 2022.

 

Dr. Darby's Extension Program has a well-established and extensive outreach program. Technical reports dating back to 2012 are available on the Program’s website. The Annual Field day draws over 225 attendees. The Program’s YouTube channel has over 300 videos with 2400 subscribers and 937,915 views. NWCS has several webinar series that focuses on tile drainage, cover crops, and no-till. Other educational efforts the NWCS has engaged in include courses for Custom Manure Applicator Certification, No-Till, and an Agricultural and Water Quality Curriculum for high school technical centers. Hence the project team has vast experience and networks to distribute the project information locally, regionally, and nationally. The program also has a strong social media presence on Facebook, Twitter, and Instagram.

Farmers and additional stakeholders will learn about the research project and results and recommendations about how to adjust their corn cropping systems to allow for better cover crop establishment through the vast network currently built by the project team.

This project combines on-farm research and outreach/education methods to transfer information and knowledge to farmers. In addition to gathering data at the farm research locations, we will utilize these sites for educational opportunities. Each year, a field day will be held at the Fiske farm to highlight project results and other cover crop and corn strategies for the northeast. The UVM Crop and Soil Annual Field Day (held at Borderview Farm in late July) will also highlight the project results and allow farmers to observe corn and cover crop strategies. Lastly, the project results will be delivered at the UVM No-Till & Cover Crop Symposium held in Burlington each February. We expect that over 400 stakeholders will be reached through these events.

In addition to the field days, we will develop a factsheet “Integrating Solar Corridors into Corn Silage Systems in the Northeast”, a video to highlight opportunity and challenges with the practice (YouTube channel 2.57K subscribers), and a 4-part webinar series addressing practices that lead to successful establishment of interseeded cover crops (125 attendees). This will guarantee that visual information will be relayed in multiple methods.

Although we are interested in sharing information related to Solar Corridors, our outreach efforts will cover broader topics that will help farmers enhance establishment of interseeded cover crops. Emphasis will be placed on modifying corn practices to encourage cover crop growth including row spacing (solar corridors), plant architecture, plant population, corn maturity, and herbicide considerations. Educational topics related to cover crops will include maximizing benefits by proper selection, timing and methods of planting. In addition, basic soil health topics will be in relation to growing successful cover crops in corn systems and their benefits to crop yield, soil quality, and farm sustainability.

As applicable, materials will be posted on the Northwest Crops and Soils Program website (https://www.uvm.edu/extension/nwcrops), available at
events (field days, conferences, workshops, etc.), advertised on social media pages, and uploaded to the Program’s YouTube channel (https://www.youtube.com/user/cropsoilsvteam/)

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.