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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #411193
Research Project: Agronomic and Engineering Solutions for Conventional and Organic Conservation Agricultural Systems in the Southeastern U.S.

Location: Soil Dynamics Research

Title: Potential fertilizer cost savings from cover crops on sandy loam soils

Author
item HAYMAKER, JOSEPH - Virginia Tech
item REITER, MARK - Virginia Tech
item STEWART, RYAN - Virginia Tech
item STEPHENSON, KURT - Virginia Tech
item Balkcom, Kipling

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/25/2023
Publication Date: 11/2/2023
Citation: Haymaker, J.R., Reiter, M.S., Stewart, R., Stephenson, K., Balkcom, K.S. 2023. Potential fertilizer cost savings from cover crops on sandy loam soils [ABSTRACT]. 2023 ASA-CSSA-SSSA International Meeting Oct. 29 - Nov. 1, 2023.

Interpretive Summary:

Technical Abstract: On the coastal plain of Virginia, sandy loam soils are prone to subsurface losses of nutrients, such as nitrogen (N) and potassium (K). Furthermore, drastic increases in fertilizer prices have reduced grain profitability. Our overall goal was to evaluate the ability of different cover crop species in monoculture and diverse mixes to increase soil organic matter, fixate N, and scavenge leached nutrients from deep within the soil profile. We initiated a long-term study in fall 2014 to observe the effects of 12 different crop rotations on soil health and cash crop yields. Treatments have been continuously maintained, with the most recent cover crop plantings occurring after corn harvest on Oct. 12, 2022 (5 treatments) or soybean harvest on Nov. 9, 2022 (2 treatments). Cover crop biomass and nutrient accumulation were assessed every two weeks, starting on March 17, 2023, until termination on April 24, 2023, prior to cash crop planting. At termination, average dry biomass was 4012 kg ha-1, with biomass increases of 44%, 87%, and 245% measured 2, 4, and 6 weeks before termination, respectively. At termination, average N accumulation was 106 kg N ha-1, valued at $169 ha-1, and average K accumulation was 124 kg K ha-1, valued at $179 ha-1. While early planted monoculture hairy vetch was not the greatest biomass producer, it accumulated the highest N and K amounts, which were 163 kg N ha-1 ($259 ha-1) and 176 kg K ha-1 ($253 ha-1). Overall, species with low C:N ratios (e.g. hairy vetch) and cover crop mixes with moderate C:N ratios (15-30 C:N) accumulated the highest amounts of N and K. In conclusion, utilizing cover crops that can scavenge leached nutrients or fixate N can reduce fertilizer costs, improving profitability of grain production on coastal plain soils.