Submitted to: Southern Nursery Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 12, 2006
Publication Date: February 6, 2006
Citation: Fare, D. 2006. Nitrogen and phosphorus levels in leachate from container-grown willow oak and sweetbay magnolia. Proceedings of Southern Nursery Association Research Conference. 50:39-43. Interpretive Summary: Environmental concerns with nitrogen and phosphorus fertilizer use at container nursery facilities and the subsequent effects of nutrient-laden irrigation effluent prompted this study. Nutrient management and potential nutrient loading into the environment from container nursery facilities must be addressed with all inputs in the production system. Substrate components and irrigation practices can affect the amount of nitrate-N and ortho-phosphate that is leached from the growing container which can ultimately affect the environment. Nutrient uptake is species dependent, thus fertilizer source and rate of fertilizer must be tailored to meet the plant needs.
Technical Abstract: Environmental concerns with nitrogen and phosphorus use at container nursery facilities and the subsequent effects of nutrient-laden irrigation effluent prompted the study. Container substrate, irrigation practices, and ferilizer use must be considered in a nutrient management plan. Quercus phellos and Magnolia virginiana, two popular landscape trees were grown in 18.9 liter (year 1) and 56.8 liter (year 2) containers in a pine bark peat substrate or pine bark substrate and irrigated with a traditional irrigation (single cycle) or a cyclic irrigation (3 cycles) application. Leachate volumes were 15 percent greater with a traditional irrigation application compared to a cyclic irrigation application. A pine bark:peat substrate (80:20, v:v) had 18 percent less leachate than a 100 percent bark substrate. Fertilizer source influenced cumulative amounts of ammonium-N, nitrate-N and ortho-phosphate in the container leachate. Nutrient uptake was species dependent, thus fertilizer souce and rate of fertilizer must be tailored to meet the plant needs.