- Nuts: hazelnuts
- Education and Training: on-farm/ranch research
- Soil Management: nutrient mineralization, organic matter
Nitrogen Fertilization for Hybrid Hazelnuts in the Upper Midwest Hybrid hazelnuts, which combine the high nut production of the European hazelnut, Corylus avellana, with the winter hardiness and disease resistance of two native American species, C. americana and C. cornuta, are being proposed as an alternative crop for the Upper Midwest. Woody perennial crops such as hazelnuts help reduce soil erosion, improve soil and water quality, reduce agricultural energy use, enhance wildlife habitat and ecosystem diversity in addition to offering farmers opportunities for economic diversification. However, information required for growing hybrid hazelnuts in the Midwest is insufficient. For example, nitrogen recommendations are based on research from Oregon and are not applicable to these hybrids in the Midwest due to differing soils, climate, genetics, and growing systems. Accurate nitrogen recommendations are important because surplus nitrogen may become an environmental pollutant, is economically wasteful, and may damage the crop, whereas crops fertilized with insufficient nitrogen may fail to be profitable. The objective of this research is to provide growers with empirically derived nitrogen recommendations. Nitrogen trials have been started on three new plantings (2003) and four established plantings (1997 and 2000) and will continue through 2005. Measurements initially will include growth parameters, both of shoots and roots, tissue nitrogen content, and winter survival. Precocity and nut yield will be measured when the plants mature. The results will be shared with current and potential hazelnut growers to improve the viability of hazelnuts as an alternative crop. If hazelnuts are found to be heavy nitrogen feeders, it will generate interest in their use in riparian buffers and for wellhead protection.
Project objectives from proposal:
The immediate goal of this project is to develop nitrogen (N) recommendations for hybrid hazelnuts, for both plant establishment and nut production, that are specific to the growing conditions of the Upper Midwest and to the hazelnut cropping system proposed here. The hybrid hazelnuts that are being used for this study were developed by Phil Rutter of Badgersett Research Farm, Canton, MN. They are a hybrid between Corylus avellana, the European hazel, which is the basis for commercial production worldwide, and two species of native American hazels, Corylus americana and Corylus cornuta, which confer tolerance to the diseases and the extreme weather of the Upper Midwest.
We believe that the proper amount of N, applied at the appropriate times, will speed the growth of young hazelnuts and bring them to nut-bearing earlier, whereas the proper amount at maturity will maximize nut yield and enhance longevity. Too much N may become an environmental pollutant, is economically wasteful, and may damage the crop, whereas too little will fail to sustain vigorously growing bushes and high nut yield. Although our research uses ammonium nitrate N, because of the ease of quantifying it, this research will be applicable to farmers using manure or legume sources of N.
We believe that the hybrid hazelnuts bred for Minnesota conditions have different N requirements because of differing soils, climates, genetics, and management system: unlike the Oregon hazelnuts, which are pruned to be trees and grown in open clean-cultivated orchards, these hybrids were bred to be grown as bushes closely-spaced hedgerows, with permanent groundcover between rows. This may increase N requirements because of higher competition, but may also reduce requirements because of tighter nutrient cycling. Another difference affecting early fertilization is that these hazelnuts are transplanted as 3 month old seedlings instead of well-developed grafted layers.
Intermediate goals are to enhance the viability of hybrid hazelnuts as an alternative cash crop for farmers of the Upper Midwest. Farmers are more likely to try new crops if they are confident of their potential for success. Our research will also demonstrate the potential for using hazelnuts to take up excess N in environmentally sensitive areas, such as riparian buffers. Incorporated into field and homestead windbreaks and living snow fences, hazelnuts are a multi-purpose crop, combining economic profit with environmental and quality-of-life benefits.
Our long-term goals are to improve the economic viability of small farms by giving farmers profitable alternatives to row crops, and to improve the environmental sustainability of food production by developing perennial cropping systems. Woody perennials such as hazelnuts reduce soil erosion, improve soil and water quality, sequester soil carbon and reduce energy use because of cessation of annual tillage. Grasses and legumes allowed to grow in the alleyways between hazel rows enhance these benefits, as well as enhancing wildlife habitat and ecosystem diversity. These contribute to better pest control and reduce the need for pesticides. Further long-term research should evaluate the potential of legumes in the alleys for supplying N.