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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Research Project #434999

Research Project: Fate of Controlled Release Fertilizer Nitrogen in Container Substrates

Location: Application Technology Research

Project Number: 5082-21000-018-07-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2018
End Date: Feb 28, 2022

Objective:
Identify the fate of applied controlled release fertilizer nitrogen from containers under varying cultural practices to maximize crop nitrogen use efficiency (amount of applied nitrogen utilized by the plant to maximize profitability during production).

Approach:
Research will consist of multiple experiments, utilizing an iterative approach, beginning in a laboratory and growth chamber before increasing in scale to a greenhouse and finally a replicated research nursery. Techniques used on conventional agronomic fertilizers will be employed to investigate nitrogen fate of controlled release fertilizers in controlled settings. This will be accomplished by investigating a fertilizer only system in laboratory experiments. Additionally, growth chambers will be constructed that allow for individual planted container systems to be investigated. We will attempt to account for all nitrogen applied by measuring initial and final fertilizer nitrogen content, ammonia and nitrous oxide gas emissions, nitrate, urea and ammonium leached, nitrogen immobilization via carbon dioxide emissions, or amount of nitrogen utilized by the crop (root and shoot) in various nursery crop production scenarios in an environmentally controlled growth chamber or greenhouse. Plant, gas, and liquid forms of nitrogen will be intermittently or continually measured using an ammonia acid trap, carbon/nitrogen analyzer, Fourier transform infrared gas analyzer and ion chromatography coupled with a flow injection analysis system. Research will be scaled to research nursery in which multiple, economically important ornamental taxa will be investigated under varying cultural practices to identify optimal time for nitrogen uptake by the plant, importance of plant nitrogen remobilization on plant uptake, and optimal time of application to minimize loss. Insight into cultural practices (ie. fertilizer placement, substrate, and irrigation strategies) effect on crop nitrogen use efficiency verified through employing N15 labeled controlled release fertilizers will provide validation and further insight into how best to improve nitrogen application efficiency.