4th UF Water Institute Symposium Abstract

Submitter's Name Rishi Prasad
Session Name Poster Session: Water quality protection and treatment
Poster Number 68
Author(s) Rishi Prasad,  University of Florida (Presenting Author)
  George  Hochmuth,  University of Florida
  Davide Cammarano, University of Floirda
  Senthold Asseng, University of Floirda
  Role of nitrogen budgets in evaluating nitrogen leaching from potato production in sandy soil: A model based approach to improve nitrogen management in Suwanee River Basin
  Increasing concentrations of nitrate in ground water in the Suwannee River Basin has raised concerns over the past 30 years. Agriculture is a major industry in the basin and is considered as an important non-point source of nitrogen pollution. Best management practices (BMP) are being encouraged for agricultural fertilization and irrigation in this watershed, however nitrate concentrations in the springs remain elevated. There is a need for quantifying sources of nitrogen losses for different crops grown in the area. Knowing a crop N mass balance will help in understanding crop nitrogen use, requirements and losses and assist BMPs for reducing the N load in the watershed. Our research was conducted on a large, diversified livestock and row crop farm located in close proximity to the Suwannee River. The objective of this study was to quantify the N mass balance components associated with potato production in sandy soils with a center pivot irrigation system for four consecutive growing seasons. Field measurements and a model based approach were used to construct the N budget for the potato production system. The potato model SUBSTOR within DSSAT was calibrated, evaluated and used to optimize the N fertilizer rates, timing, and irrigation management. Leaching was found to be a major pathway for N loss from potato systems and comprised 35 % of the total N fertilizer input.