Should Dairy Manure be Applied to High Value Crops?.

In Southern Idaho, we are faced with the need to apply dairy manure to a larger land base, which would mean applying manure to fields with potatoes, sugar beets, wheat, and/or barley in the rotation. The goal of this eight year study, which is entering its third year, is to evaluate the agronomic response and greenhouse gas emissions in an irrigated high-value cropping system to both moderate and intensive dairy manure applications. The crop rotation is wheat, potato, barley, and sugar beet, with manure either fall applied annually or biennally before the grain crop at three rates (8, 16, and 24 dry ton/acre). A fertilizer only and a control plot (no nutrients applied) are also included. Responses to yield, crop quality, soil nutrients, soil organic matter, soil salts, plant nutrient uptake, N mineralization, nitrous oxide emissions, disease pressure, and insect pressure are currently being evaluated.