Dairy manure effects on sugar beet yield, quality, and nutrient uptake potential

Authors: Leytem, April; MOORE, AMBER - Oregon State University; Dungan, Robert; Rogers, Christopher; Strausbaugh, Carl

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2025
Publication Date: 8/18/2025
Citation: Leytem, A.B., Moore, A.D., Dungan, R.S., Rogers, C.W., Strausbaugh, C.A. 2025. Dairy manure effects on sugar beet yield, quality, and nutrient uptake potential. Crop Science. https://doi.org/10.1002/csc2.70144.
DOI: https://doi.org/10.1002/csc2.70144

Interpretive Summary: Concentrated dairy production coexists with large-scale crop production in southern Idaho. This results in large amounts of manure available for crop production, but the suitability of manure for sugar beet production is not well understood. Research was conducted to determine soil properties, sugar beet yield and quality, and economic value response to manure applications. Soil nutrients nearly universally increased with increasing manure applications and thus, soil salts increased as well. At the highest annual manure application rate, soil salts exceeded the concentration at which sugar beet growth can become limited. Sugar beet root yields were greater in manure treatments vs fertilizer and control treatments; however, root sucrose concentration decreased, and root contaminants (nitrate and salts) increased with higher manure application. Despite this, estimated recoverable sugar remained constant indicating similar returns for the grower. Data from this long-term manure application study provides evidence of both positive and negative effects on the plant-soil system in relation to sugar beet production. Decisions on the exact place of manure for sugar beet in on-farm operations should be approached with a systems-level view in order to balance the needs of manure disposal with sugar beet production in relation to grower and industry returns.

Technical Abstract: Concentrated dairy production coexists with large-scale crop production in southern Idaho. This results in large amounts of manure available for crop production, but the suitability of manure for sugar beet production is not well understood. Research was conducted to determine soil properties, sugar beet yield and quality, and economic value response to manure applications. Research was conducted over an 8-y period with two application frequencies (annual and biennial) at dry-weight rates of (18, 36, and 52 Mg ha-1) and a synthetic fertilizer-only and a non-amended check. Nearly all soil nutrients increased with increasing manure rates with particularly high levels of NO3-N and Olsen-P at the highest rates. At the highest annual rate, soil electrical conductivity exceeded 2 ds m-1, the concentration at which sugar beet growth is limited. Root yields were greater in manure treatments vs fertilizer and control treatments; however, beet sucrose concentration decreased, and NO3-N and conductivity increased with higher manure application. Despite this, estimated recoverable sugar remained constant indicating similar returns for the grower. Results indicate the potential for manure usage in sugar beet production but convey concerns that may arise due to increased soil salinity alongside issues that exist in terms of crop quality.