6 minute read
Field Reports
Rodale Institute scientists and farm managers around the country are studying strategies for more effective and productive regenerative organic agriculture.
Cover Crops Beat Black Plastic
What we’re learning: Organic strawberries grown with a cover crop produced yields comparable to those of strawberries grown in black plastic mulch, according to the preliminary results of a study at the Rodale Institute California Organic Center in Camarillo, California. The researchers found that sorghum-Sudangrass, a cover crop that reaches 5 to 12 feet tall, worked effectively to prevent the growth of weeds throughout the strawberry growing cycle and contributed essential biomass to the soil.
Why it matters: Many strawberry growers rely on black plastic mulch to suppress weeds, but it offers nothing for the soil’s health and creates waste that’s not biodegradable. Regenerative organic farmers can plant sorghum-Sudangrass to control weeds and nourish the soil food web while still harvesting the same volume of this high-value crop.
WEED-BLOCKING ROTATIONS
What we’re learning: Weed management is a common challenge for organic farmers. The Diverse Systems Trial at the Rodale Institute Midwest Organic Center in Marion, Iowa—near Cedar Rapids— is examining how several four-year rotations involving corn, soybeans, cover crops, small grains, and spring peas can interrupt weed cycles. Cattle grazing is intentionally integrated into the crop rotation on half of the research plots to understand how this may help to recycle minerals (and thereby reduce the need for fertility inputs), reduce tillage, manage weeds, and improve soil health and biodiversity overall.
Why it matters: Conventional operations typically plant a few genetically modified crops (mostly corn and soybeans) designed to withstand treatments of toxic weed-killing herbicides. They also use heavy amounts of nitrogen fertilizer. These practices contaminate water, soil, and air and harm human health.
Regenerative organic farmers protect the soil and its inhabitants, as well as human health, by eschewing the use of herbicides and synthetic fertilizers and avoiding frequent mechanical cultivation and tillage. Identifying a crop rotation that improves soil health and reduces weed pressure and the need for costly fertilizers adds a valuable strategy to help regenerative organic farmers be more successful.Regenerative organic farmers protect the soil and its inhabitants, as well as human health, by eschewing the use of herbicides and synthetic fertilizers and avoiding frequent mechanical cultivation and tillage. Identifying a crop rotation that improves soil health and reduces weed pressure and the need for costly fertilizers adds a valuable strategy to help regenerative organic farmers be more successful.
Healthier Colorful Corn
What we’re learning: A breeder at Texas A&M University has developed a purple corn variety that is highly nutritious. The Rodale Institute Southeast Organic Center in Chattahoochee Hills, Georgia, is evaluating the hybrid to determine if it can tolerate the challenges of the high temperatures, drought, weeds, and insect pests found in the Southeast. Initial research findings from the first year of the study have shown that the Texas hybrid has had strong germination rates, high yields, and the ability to withstand the region’s weed pressures.
Why it matters: Purple corn isn’t just colorful. It’s a rich source of anthocyanins, phytonutrients that have been linked to a reduced risk of heart disease and cancer.
Clean Water
What we’re learning: Stormwater runoff from farms causes catastrophic flooding in some areas. Even worse, it carries excess chemical fertilizers into freshwater lakes, rivers, and streams, causing algae to grow faster than ecosystems can handle and diminishing the oxygen that aquatic life needs to survive. The Watershed Impact Trial, a partnership between Rodale Institute and Stroud Water Research Center in Avondale, Pennsylvania, is a six-year assessment of the impact of different farming practices on the freshwater supply. It is tracking the quantity and composition of runoff; residues of pesticides, fungicides, and herbicides on crops and in the water and soil; the physical, chemical, and biological properties of soil, including water infiltration; stream water quality; and the presence of harmful microbes in the water.
Why it matters: Cover crops increase soil fertility and reduce the risk of soil erosion and of toxic fertilizers getting into surface water and groundwater. Healthy soils that have maintained their nutrients are more stable and hold more water, decreasing the risk of runoff and improving crop yields during periods of drought.
Microgreen Management
What we’re learning: Microgreens are immature vegetable shoots (harvested 7 to 21 days after germination), and they are prized by healthy eaters for their concentrated nutritional content.
Organic microgreen growers must optimize temperature and humidity conditions to ensure healthy growth and fend off diseases. Researchers at the Rodale Institute Pocono Organic Center in Long Pond, Pennsylvania, have evaluated strategies to stimulate yields of broccoli microgreens while protecting the plants’ health. They found that inoculating the planting medium with Trichoderma, a widely used biocontrol agent, improved growth of the plants by increasing nutrient absorption and protected them against diseases.
Why it matters: Microgreens are an easy, low-cost, high-value crop for organic producers. Sales of microgreens in the United States are estimated at $1.74 billion in 2024, and profit margins for growers typically exceed 15 percent.
Five Objectives
Rodale Institute’s regional resource centers have been established to achieve these goals.
Increase the number of farms and acres in organic production in the region.
Establish long-term research trials to determine changes in soil health, yields, economic models, and more in unique climates and soil types.
Solve challenges, including pest, disease, and weed management, for organic farmers in their regions.
Provide farmer training, extension services, and pathways to market.
Develop partnerships with local organizations and research institutions interested in organic production and farmer training.
