Using Summer Annual Forages as an Alternative to Double-Crop Soybean
By Liz Ridenour, Amanda Grev, and Jeff Semler
As of this writing 99.16% of Maryland is experiencing D0-D4 drought conditions according to the U.S. Drought Monitor. This is down from 100% a week ago and 99.94% on January 1. The recent rains have certainly perked things up but have done little to reduce the long-term impacts of drought. One of those impacts is the reduced yield of first cutting hay and the diminished promise of second and third cuttings. This brings us to a potential opportunity.
In most years, soybeans are a common choice for double cropping following wheat harvest in July, providing a second harvest and source of income for the producer, and nitrogen fixation in the soil in preparation for the fall planting season. However, nitrogen fixation from soybeans is not significant enough to reduce the need for nitrogen fertilizer following soybean harvest, and double-cropping using soybeans may leave the soil with less nutrients, as growing soybeans draw phosphorus and potassium from the soil.
One viable alternative to soybean double-cropping is the planting of summer annual forages. Not only do summer annual forages have the potential to improve soil health, mitigate pests, suppress weed growth, and reduce soil erosion, but they can also be utilized as a fast-growing forage for silage, hay, and direct grazing, making them an attractive and sustainable alternative to double-crop soybeans.
Summer annuals improve overall soil health in several ways. Not only do they protect the soil from the erosion characteristic of bare soils and add organic matter and nitrogen back into the soil, but they can also help to break pest cycles by attracting beneficial pollinators and predatory insects. Summer annuals provide shade for the soil during the hot summer months, lowering soil temperatures, aiding in soil moisture retention, and preventing weeds from sprouting. Summer annuals grown for forage can be grazed, harvested as silage or hay, or green chopped.
Options for Summer Annual Forages:
| Season Type | Functional Class | Examples |
|---|---|---|
| Cool Season | Brassicas | Radishes, turnips (Barkrant, Purple Top are both heat-resistant varieties), Bayou Kale, Titan Forage Rapeseed |
| Cool Season | Grasses | Annual Ryegrass, Black Oats, and Barley |
| Cool Season | Legumes | Crimson Clover, Hairy Vetch, and Peas |
| Warm Season* | Forbs | Buckwheat, Sunflower |
| Warm Season* | Grasses | Sudangrass, Foxtail Millet, Japanese Millet, Hybrid Pearl Millet, and Grain Sorghum |
| Warm Season* | Legumes | Sunn Hemp, Cowpeas or Forage Soybeans |
*Warm season annual forages are well-adapted to high temperatures and can withstand drought, maintaining soil moisture throughout the summer months.
It is important to keep both prussic acid and nitrate toxicity in mind when choosing annual summer forages. Nitrate poisoning is most likely to occur when plants are harvested as hay and fed, as stressful conditions cause the plant to halt its conversion of nitrates to amino acids, resulting in buildup of nitrates in the plant matter. Prussic acid is a particular risk in Sorghum-Sudan and Sudangrass hybrids, and can occur in damaged plant tissues, by severe drought or frost.
For those producers that cannot graze these crops or have the equipment to harvest them, this may sound like a non-starter. However, before you dismiss this opportunity think about which of your neighbors could benefit and harvest or graze these crops. This could be a win-win for both of you. The grower receives cash from the crop, and the neighbor can acquire some much-needed forage reserves close to home.
First and foremost, agriculture is a community endeavor, and farmers have often looked out for each other. In this case it is mutually beneficial.
So, before you dismiss this idea, remember the phrase that keeps many in a rut, “this is the way we have always done it.” Rethink your options. Who knows, you might open future opportunities by simply shifting your paradigm.
As always, for specific recommendations for your area, contact your local extension agent.
Resources:
Penn State Extension:https://extension.psu.edu/alternative-forages-for-spring-and-summer-planting
Iowa State Extension: https://crops.extension.iastate.edu/post/maximizing-forage-production-summer-annuals
Farm Progress.org: https://www.farmprogress.com/crops/why-i-no-longer-plant-greedy-beans-
Nebraska Institute of Agriculture and Natural Resources: https://cropwatch.unl.edu/2019/summer-annual-forages-after-failed-wheat/
Plant Cover Crops:https://plantcovercrops.com/my-favorite-cover-crop-after-wheat/
This article appears in June 2026, Volume 17, Issue 3 of the Agronomy News.