Terminating Cover Crops

Photo source: Mike Stanyard

Article by Mike Stanyard - NWNY Dairy, Livestock and Field Crops Extension Team. 

This article was originally published in NWNY Dairy, Livestock and Field Crops Extension Team’s April 2017 Ag Focus and is published here with Mike Stanyard's permission.

So far, it looks like cover crops did well despite the lack of a prolonged blanket of snow this winter.  This makes our cover crops even more valuable as one of their main purposes is to keep our soils from blowing and washing away.  It was cold enough that the species that were supposed to winterkill like tillage radish and oats died. For those that remain alive like cereal rye, triticale, wheat, annual rye and clover species, we will have to come up with a plan on how to manage them.

Some of these overwintering cover crops will be used as a forage crop and therefore will be cut at the appropriate time (Growth Stage 9 for triticale) for optimum feed value.  Others will be mowed/crimped, tilled under, or terminated with herbicides.  Each of these has restrictions depending on what production system you utilize (ie. strictly grain based, no-till, or organic).  If cover crops are not dealt with in an appropriate manner, they can become weeds and compete with our production crops.  We saw that first hand in a drought situation last year. I have put together some advice on herbicide termination from the Midwest states on some of our commonly used cover crops.

Annual ryegrass (Lolium multiflorum), also called Italian ryegrass or common ryegrass, has become a very popular cover crop in NY but has a confusing name.  It is not an annual and survives the winter very well.  Do not confuse annual ryegrass with cereal rye.  Annual ryegrass is a good cover crop because of its ability to rapidly germinate in the fall, grow aggressively in the spring, and add substantial root and forage mass to the soil profile. Here is some advice from University of IL on proper termination with herbicides (http://bulletin.ipm.illinois.edu/?p=3552).

• Make applications prior to 8″ plant height
• Glyphosate rates of at least 1.25 lb ae/A are required, although 2.5 lb is preferred for annual ryegrass termination
• Ryegrass must be actively growing, and it is recommended that applications occur only following three consecutive days when air temperatures have been above 45 F
• The addition of saflufenacil to glyphosate can improve control of annual ryegrass
• Combinations of paraquat, metribuzin and 2,4-D or dicamba can control small ryegrass (<6″ in height), but are not recommended for control of larger plants
• Avoid using PSII herbicides (atrazine & metribuzin) in mixtures with glyphosate, as they can cause antagonism and poor control of annual ryegrass.

Cereal rye. Glyphosate at a rate of 0.75 lb ae/A will effectively control both species up to 18 inches tall. Mixtures of glyphosate plus 2,4-D, chlorimuron, chloransulam, atrazine, or saflufenacil can also be applied for additional control of other cover crop species (specifically broadleaf species) and residual control of summer annual broadleaf weeds. Depends on what crop species is going to be planted.  The nonselective herbicides paraquat and glufosinate are less effective than glyphosate on these species.

Gramoxone SL (paraquat) applied at 3 to 4 pints per acre works well on smaller rye before it reaches the boot stage.  Add a nonionic surfactant to the spray tank to enhance penetration and total kill.  If you will be planting corn and choose to use Gramoxone SL, consider adding 1 quart of atrazine per acre to improve control of the rye.  (personal communication, Mike Hunter, CCE).  In 2009, research by Bill Curran at Penn State University, found that the additional of 1 quart of atrazine per acre, when used with Gramoxone, provided 99% control of 8-10 inch tall rye.  Only 70% control of the rye was achieved when Gramoxone was used alone in this study.

Crimson clover and Austrian winter peas are two popular legume species used as cover crops that typically do not winter kill and require a spring termination.  I have seen control issues with large pea vines with glyphosate.  Information on control of these species with herbicides is limited, but cover crop guides advise that glyphosate and 2,4-D/ dicamba easily control crimson clover and winter peas.

University of Wisconsin has a nice fact sheet with additional cover crops which lists termination methods preferred and herbicide options (https://host.cals.wisc.edu/wcws/wp-content/uploads/sites/4/2013/03/WCWS_204_cover_crop_termination_WEB.pdf).

Download a PDF of this article.

Resource Spotlight: Soil Health Management Planning Worksheet

Getting started with a soil health management plan can be a daunting task. Even farmer's who are experienced with no- or reduced-till and cover crops may find themselves struggling to make decisions on where to go next in their soil health journey. If you're looking to get your soil health toes wet, or just need help re-establishing your goals, the Soil Health Management Planning Worksheet is a short, simple way to get you headed in the right direction. PDF file available for download here.

Resource Spotlight: Adaptation Workbook

The USDA and the US Forest Service Department of Agriculture recently launched a digital Adaptation Workbook for Forestry and Agriculture. “The Adaptation Workbook is a structured process to consider the potential effects of climate change on forest ecosystems and design land management and conservation actions that can help prepare for changing conditions.” 

The workbook has a lot of flexibility to accommodate a wide variety of enterprises and relies on farmers gaining an understanding of their own geologic and climatic conditions, as well as having a strong grasp of their farm’s objectives and management goals. The Workbook was created because “more and more information is becoming available on climate change projections and potential impacts on natural resources and agriculture. Unfortunately, most of this information doesn't seem applicable because many land owners and managers are unsure how climate change might actually apply at the scales that are relevant to their work. The Adaptation Workbook was created to bridge this gap.”

The Workbook consists of 5 basic steps:

1. Define goals and objectives
2. Assess climate impacts and vulnerabilities
3. Evaluate objectives considering climate impacts
4. Identify adaptation approaches and tactics for implementation
5. Monitor effectiveness of implemented actions

While the main focus of the workbook is to help create a structure for climate adaptation, there are also elements of mitigation within the process. Though complete mitigation of climate change is likely impossible, there are many adaptation projects that go hand in hand with mitigation strategies, and vice versa. 

The Workbook can be used for Agriculture and Forestry. PDF versions of the workbook are also available at the links below. To use the online version, visit  https://adaptationworkbook.org/

Adaptation Resources for Agriculture

Forest Adaptation Resources: climate change tools and approaches for land managers, 2nd edition.

Resource Spotlight: NRCS Conservation Webinars

With the weather in Western NY being slightly less than pleasant in recent weeks, the chance to sit down, take a load off, and learn something new is upon us and USDA Natural Resource Conservation Services Conservation Webinars series is a great place to do just that. 

2016 offered a wide variety of webinars, but the following offer soil health specific content. If you’re interested in learning the basics of soil health check out The New Division of Soil Health: Approach and Benefits, Biological Indicators of Soil Health: What they are, how they are measured, and what is on the horizon?, and Soil Erosion: A Historical Perspective. 

There’s plenty to learn through these webinars about grazing in general, but Integrating Grazing into Cropping Systems, and Grazing Management on CRP Acres to Improve Soil Health will give you a soil health POV. 

Other soil health related topics include Farming Implements in Action: Impacts on the Soil, Erosion Potential of Tillage Systems, and Economics, Managing Soil Quality in Forests, Soil Health Impacts on Pest Management, and Soil Health in High Tunnel Production.

Recordings of all 2016 Conservation webinars are available here and can be viewed at any time.

Upcoming webinars for 2017 are full of promise. There are two webinars scheduled that will feature first hand view and commentary from farmers including Soil Health Economics - A Farmer's Perspective, and Managing Cover Crops in an Arid Region: A Farmer's Perspective. 

The basics of soil microbes will be covered in Soil Microbes Every Agronomist Should Know, and grazing for soil health will be discussed in Using Adaptive Grazing to Improve Soil Health in Grazing Ecosystems. 

Soil Health impacts on resource concerns, specifically water quality, will be covered in Movement of Nutrients through Soils: Impacts of Land Management (or lack of) on Water Quality, and various operation specific discussions and their relationship to soil health will be covered in Soil Health Challenges of High Disturbance Crops, Improving Soil health in Irrigated Intensive Vegetable Production, and Improving Soil Health on Confinement-based Dairies.

New live presentations will be available throughout 2017. Click here to see a full list of offered webinars and their scheduled dates and times. Recordings of each webinar become available within a few weeks of the live presentation if you are unable to attend day of.