2017 ASHS Annual Conference

Plant nitrogen use efficiency (NUE) is important for minimizing fertilizer costs and reducing negative impacts of agriculture on the environment. Nitrogen use efficiency can be influenced by many factors including soil properties, root architecture and physiological differences such as the ability of the plant to utilize organic N directly in the form of amino acids. Greenhouse experiments were carried out to determine the role of compost and C to N ratio on amino acid turnover, uptake and NUE of cultivated and wild relatives of strawberry (Fragaria sp). A direct comparison of ¹⁴C and ¹³C /¹⁵N dual label methodologies for sensitivity in measuring amino acid uptake was also conducted. While different methodologies were not always consistent, results show that compost addition increased both the rate of amino acid cycling and the amount captured by plants, while the role of C to N ratio was less pronounced. Significant differences in NUE were also found between cultivated strawberries Fragaria ananassa and their wild relative Frageria chiloensis. Some cultivated varieties were more N efficient than others indicating significant variability exists for both variety selection and future breeding efforts. Further research is needed to screen current varieties in the greenhouse and field in order to select cultivars that yield well under reduced N environments, hence reducing reliance on expensive inputs and decreasing potential loss to the environment.