1. Western Crop Science of America Conference June 10-13, 2013 Pendleton, OR Olga Walsh Assistant Professor, Soil Nutrient Management Western Triangle Agricultural Research Center Montana State University Foliar Nitrogen Fertilizers in Wheat Production

2. Outline Literature review: Rationale Uptake Mechanisms Potential Benefits Efficiency MSUs Foliar N study in spring wheat 3. Rationale for foliar application Plants are known to attain water and nutrients though foliage (Wittwer and Teubner, 1959) Foliar is Beneficial/Potential when: Soil applied nutrient uptake is limited due to soil conditions (pH, soil moisture) Significant potential for loss soil applied nutrients (leaching, runoff)(Fernandez et al., 2013) 4. Foliar N products manufacturers claim that foliar feeding increases NUE, saves money, labor and time to wheat producers. Limited research on foliar fertilizers and contradicting results Negative results mainly due to leaf burn Justification 5. Where does foliar fertilization fit in? Foliar fertilization can result in rapid nutrient absorption and utilization to correct deficiencies or to merely prevent nutrient shortages during critical periods of growth. However, unlike roots, plant leaves are not adapted to assimilate large amounts of nutrients and meet the bulk of the nutrient requirement (IPNI, 2008). 6. 1. Adsorption (adherence to the leaf surface) 2. Movement through leaf surface 3. Absorption (cellular compartmentalization) 4. Translocation and utilization by the plant (Fernandez et al., 2013) Mechanism sequence 7. Permeation studies: Leaf stomata (Below et al., 1984) facilitate the mineral nutrient uptake Stomata size ~0.9 nm (Tyree et al. ,1990; Schonherr, 1976; Schonherr and Bukovac, 1979) - diameter of many ions UAN. 37. Conclusions: Protein Yield Evaluating NUE in spring wheat should take into an account both grain yield and protein content. At dryland sites, HNRGN resulted in a combination of highest protein yield At the irrigated site, the same trend was observed, but the differences were not significant. The lowest protein yield at the dryland sites was achieved with UAN, and with LU - at the irrigated site. HNRGN resulted in superior grain yield, and protein yield at all three experimental 38. THANK YOU!