The North Carolina Department of Agriculture & Consumer Services’ Agronomic Services Division announced on Apr. 2 the release of a new step-by-step guide designed to help farmers assess the nutrient value of their cover crops and potentially reduce fertilizer use.
The new resource comes as fertilizer prices have increased and more growers are adopting soil health practices. The guide aims to give practical, actionable steps for farmers to collect biomass samples from their cover crops, submit them for analysis, and calculate nutrient values per acre before terminating the crop each spring.
“There has been a growing interest in the nutrient value of cover crops in recent years,” said Dr. Kristin Hicks, lab director of the Plant/Waste/Solutions/Media Lab. “With recent spikes in fertilizer prices, we expect that interest to increase significantly. We created this quick guide with the goal of making it as easy as possible for growers to determine how much a cover crop could offset the need for fertilizer inputs.”
One key recommendation is that growers should use the Waste and Compost Analysis service instead of Plant Tissue Analysis when submitting samples—a change some may find unexpected. “In the case of cover crops, you aren’t growing it for harvest but as a fertilizer for eventual land application or incorporation, similar to manure or compost,” Hicks said. “The Waste Analysis is designed to report nutrient concentrations on a per acre basis for this purpose.”
Hicks also highlighted how quantifying nutrients can support better decision-making: “Growers want to get the most out of the cover crops they invest in,” she said. “By giving them straightforward sampling methods and quick nutrient calculations, we hope to empower them to reduce input costs while improving their soil’s long-term productivity.”
Cover crops offer several benefits beyond fertility management; legume species like crimson clover and hairy vetch fix atmospheric nitrogen while cereal species such as barley and rye scavenge residual nutrients from previous plantings. These practices can also improve soil organic matter, suppress weeds, reduce erosion, and enhance water retention.
Detailed guidelines and printable resources are available through Agronomic Services at www.ncagr.gov/Agronomic-Services under “Determining the Nutrient Value of Cover Crops.”
