Part I: Planning Spring Cover Crops
By Chuck Schembre, Understanding Ag, LLC
In the fall of 2023, NM Healthy Soil partnered with Green Cover Seed to distribute one hundred 25-pound bags of a custom designed spring cover crop seed mix among attendees at the annual REGENERATE Conference, taking place in Santa Fe, New Mexico. This article is the first in a three-part series providing guidance on how to plan, plant and harvest a diverse spring cover crop in the Western United States.
A happy cover crop seed recipient at the 2023 REGENERATE Conference. Photo by Isabelle Jenniches CC BY 2.0
If you are looking for opportunities and strategies to increase diversity and maximize your cover cropping benefits, consider the value added from Springtime cover cropping. Adding spring covers into rotations is less common than winter or summer cover cropping and while it can be very advantageous within a specific context, the primary benefits and management are often not fully realized or understood.
Generally, spring is a time to plant cash crops, increase grazing activities, and mow vegetation in orchards. In livestock or haying operations, spring seeding is a typical practice to overseed fields or establish a new pasture or hay crop. Therefore, in a livestock operation, a spring cover crop seeding can be considered a cash crop and the direct economical benefits are much easier to assume (feed for livestock). But why should a farmer or gardener consider seeding spring cover crops? When is the ideal timing? And how do spring cover crops increase a farmer’s bottom line?
As with all cover crop educational resources, the bigger picture and major impetus of cover cropping is to increase soil health and farm ecosystem function. Spring cover crops allow for establishing a wide diversity of plants given the mild temperatures and available moisture, plus warm temperatures to come. This combination of conditions increases the overall opportunities to improve soil health, enhance insectary and pollinator benefits, and increase forage diversity and feed value.
Spring Mix Composition
In this series of articles we are going to look at a spring mix designed by Green Cover Seed and generally discuss ways to manage a diverse mix from seeding to termination. It is important to understand when seeding a diverse mix with more than ten species, not all the species will germinate or perform well. The overall success of each species will be specific to your farm context, and is greatly dependent on the current condition and health of the soil, precipitation, seeding methods, and irrigation availability. As long as 5-6 species perform well, large benefits will follow with little management required.
Ideally, the cover crop will be composed of multiple grasses, legumes, brassicas, and other broadleaf plants. Although certain plants will be in the same plant family, each provides unique characteristics, such as different root and leaf architectures, root exudates, microbial associations, weed suppression benefits, nutrient cycling and scavenging capabilities, forage value, and insectary benefits.
Here is the list of species that comprised the mix designed for NM Healthy Soil’s spring cover crop seed campaign. It’s a great diverse mix of species and their individual characteristics check many, if not all of the boxes:
- Spring Forage Pea – large N fixation and residual N from decomposition, biomass, weed suppression.
- Common Vetch – N fixation, good biomass, pollinator.
- Crimson Spring Lentil – low water use, shallow taproot, good mycorrhizal support for a legume, and high forage and hay quality.
- Kentucky Pride Crimson Clover – N fixation, pollinator, biomass, weed suppression.
- Balady Berseem Clover – N fixation, pollinator, weed suppression, no bloating high quality forage, more palatable than alfalfa, low water use.
- Cosaque Black Oats – fibrous root, mycorrhizal benefits, good biomass
- Lavina Beardless Spring Forage Barley – fibrous root, mycorrhizal benefits, good feed quality grain, lower water use requirements than most cereals.
- Nitro Radish (daikon) – nutrient scavenger, compaction breaker, large channels created for subsoil infiltration and channels for crop roots to grow, provides biofumigation reducing pest and nematode pressure.
- Trophy Rapeseed – Deep penetrating tap root, great nutrient cycler and nutrient scavenger of N, high forage value.
- Purple Top Turnip – great forage crop, weed suppression, overall great nutrient scavenger, fast growing root.
- Brown Flax – very heat tolerant, phosphorus mobilizer, attracts beneficials, diversity enhancer.
- Baldy Safflower – very drought tolerant, compaction breaker, large tap root and nutrient scavenger, spineless variety supports good palatability for grazing, produces oil, seed feed for birds.
- Super Bee Phacelia – Exceptional pollinator with a high-quality source of nectar and proven to increase honey bee production, extensive fibrous root system increases organic matter.
Images by Green Cover Seed
Integrating Spring Covers into Crop Rotations
How spring cover crops fit within the rotation is very contextual and farm specific, so I am going to begin with an emphasis on revisiting the six principles of soil health as the main driver of our decisions and planning.
Where on the farm do you need to: 1) reduce disturbance, 2) increase soil armor, 3) increase diversity, 4) need to increase living roots, 5) have an opportunity to integrate or improve grazing, and 6) what is your context?!
No matter where and how you decide to add spring covers, you will achieve numbers 1-4 depending on how you manage them. In addition, we need to evaluate how to best include cover crops to improve and support the Four Ecosystem Processes on the farm – Energy Flow, Water Cycle, Mineral Cycle and Diversity. With proper management of cover crops we will be supporting a net benefit to the Four Ecosystem Processes just mentioned. Below I will discuss some options and ideas around rotations and optimizing the benefits. In all decisions moving forward, always keep in mind your specific ecological farm context, and get creative with timing and methods for establishing covers.
Vegetable Farm and Garden:
For the market gardener or home gardener, spring covers are a phenomenal tool to provide extended rest to beds planned for Fall and Winter crops. Beds that were bare and had poor armor over the winter are good locations to provide spring and summer time rest with covers. They can be used as a pollinator-insectary and after termination provide mulch for the next planting, or around the garden. The mix described above will also be increasing nutrient cycling and nutrient availability through fixation, microbial mineralization, and mycorrhizal associations, which will support the next crop’s nutritional needs.
In the Orchard:
Establishing Spring covers in the orchard is not as easy or practical in the arid-West, unless you have overhead irrigation, micro-sprinklers spraying out into the alleyway middles, or good late spring to early summer monsoon rains. In warmer Southwest climates, spring covers can be seeded in late Winter or early March, and rely on springtime rains.
Grazing and Feed:
Looking at each individual species on the list above, it is obvious there are great nutritional feed benefits. This mix can be overseeded to a degraded or poor producing pasture to increase diversity and serve as a biological “primer” providing all the soil health benefits we are aiming to achieve.
In the next article we discuss options and considerations for establishing a spring cover crop. Click HERE to read the second article in the series.
A happy cover crop seed recipient at the 2023 REGENERATE Conference. Photo by Isabelle Jenniches CC BY 2.0
Jim Parker
Thank you for including “conducting short grazing durations and long rest periods”
If it possible you might add Planned grazing which includes consideration of other organisms above and below the soil surface by varying the timing of grazed or harvested crops from year to year.
Thanks again for a very thought-full post.