Nutrient Management Research Database
General Information
Research Title
Fertigation Boosts Optimum Nitrogen for Tomatoes and Peppers
Link to File
Research Specifications
Crop: Tomato
Soil Type: Sandy Loam
Country: Canada
Year: 2006
Authors
Zhang, T., Tan, C., & Bruulsema, T.
Summary/Abstract from Original Source
- Fertilizing vegetable crops requires a delicate balance between yield, quality, and environmental impact.
- Fertigation increases response to nitrogen (N) and provides greater opportunity to control rates to optimum levels.
- This article discusses optimum rates of nitrogen fertilization for yield and quality, while minimizing environmental impact, in Ontario Canada.
Research Highlights
Design and Methods
- The experiments on both crops included four rates of N and three rates of P in all 12 combinations.
- All of the P and 40% of the N requirement was applied pre-plant.
- The remaining N was supplied by fertigation.
- The soils were Granby sandy loams or loamy sands, with organic carbon content of 1.7%, at the research station in Harrow, Ontario.
- Soil P and K fertility was very high–generally above 60 parts per million (ppm) Olsen-P, and above 200 ppm exchangeable K.
Results
- Over three growing seasons - 2003 to 2005 - optimum marketable yields required 180-214 lb/A for green peppers and 190 to 270 lb/A for tomatoes.
- These rates exceeded recommendations for the soil type by two to three fold.
- N removal efficiency ranged from 50% to 80% for tomatoes fertilized at the mean optimum rate of 240 lb/A.
- At that rate, N recovery efficiency ranged from 31% to 68%.
- Peppers were less efficient, with N removal efficiencies between 22% and 30% and recovery efficiencies from 24% to 32% at the mean optimum rate of 200 lb/A.
- When N rates exceeded optimum the proportion of green tomatoes increased and soluble solids decreased.
- P addition did not affect soluble solids.
- For both tomatoes and peppers, rates of N above optimum tended to dramatically increase residual soil nitrate.