|Braun, Lois -|
|Gillman, Jeffrey -|
|Hoover, Emily -|
Submitted to: Canadian Journal of Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 11, 2011
Publication Date: July 1, 2011
Repository URL: http://hdl.handle.net/10113/53751
Citation: Braun, L.C., Gillman, J.H., Hoover, E.E., Russelle, M.P. 2011. Nitrogen fertilization for young established hybrid hazelnuts in the Upper Midwest of the USA. Canadian Journal of Plant Science. 91(5):907-918. Interpretive Summary: Alternative fuels can be made from a wide variety of biomass feedstocks including waste wood, crop residues, and other plant-based materials. Producers will be most interested in feedstocks that provide additional income streams. Hybrid hazelnut can be grown as hedgerows in other crops such as alfalfa, as living snow fences, and on land that is not easily cultivated for annual crops. Hybrid hazelnut is a new crop, is still in the early stages of variety development, and little is known about the nitrogen need of these shrubs before they enter their prime nut-bearing years. Nitrogen fertilizer often is the largest input of energy in agriculture and can be the source of significant contamination of water and the atmosphere. In earlier research, we found that fertilizer nitrogen applied soon after transplanting reduced plant survival and that there was little nitrogen response in shrubs in the following 2 to 3 years. In this report, we show that fertilizer nitrogen responses of plants from 4 to 10 years of age were positive only on soils with low organic matter levels and where other soil nutrients did not limit crop growth. Requirements for nitrogen were lower than for the European hazelnut trees grown in milder climates. Our data support the leaf nitrogen analysis used with the tree-type hazelnuts, except that the threshold of sufficiency is lower than 2.2% in hybrid hazelnut. This information should reduce the cost and improve the environmental benefits of hybrid hazelnut production.
Technical Abstract: Hybrids of Corylus avellana, C. americana, and C. cornuta are proposed as a new crop for the Upper Midwest. Anecdotal information from midwestern growers suggests that these hybrid hazelnuts have high N requirements, but this has not been confirmed in replicated trials. Current nitrogen (N) recommendations for hazelnut production are based on research from the Pacific Northwest and may not be applicable to these hybrids in the Upper Midwest due to differing soils, climate, genetics, and growing systems. Three years of N rate trials on four plantings that were 3- to 6-years old at the start showed that N responses of hybrid hazelnuts fit patterns for other woody crops: no N responses were found on soils with high organic matter nor on soils with suspected P or K deficiencies. Where N responses were observed, they suggested that the N requirements of hybrid hazelnuts in the Upper Midwest are relatively low compared with those of European hazelnuts in the Pacific Northwest. Leaf N concentrations were within the expected ranges established for European hazelnuts in Oregon, suggesting that Oregon's standards may be applied to hybrid hazelnuts, except that 2.2% leaf N should be considered adequate, rather than a threshold to sufficiency.