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Home Publications National Nursery Proceedings 2000 Slow-Release Fertilizers in Bareroot Nurseries

Slow-Release Fertilizers in Bareroot Nurseries

Maintaining sufficient soil fertility in tree nurseries for good tree growth can be implemented by annually performing soil analyses and following a fertility maintenance program. Percentage recovery by trees of fertilizer applied indicates efficiency of fertilizer use. There is a wide variation in the recovery among the various fertilizer elements. Our research has shown that, of the primary nutrients, nitrogen recovery is much more variable, spanning from deficits to almost complete recovery. Low efficiency of nitrogen recovery is the usual rather than the exceptional occurrence. Soil characteristics, climatic conditions, cultural practices, fertilizer source, and fertilizer application method influence nutrient recovery. Most applied nitrogen is either recovered rather soon after application or lost from the soil-plant system. An approach to resolving the problem associated with nitrogen mobility and environmental protection has resulted in the development, testing, and use of several controlled-release or slow-release fertilizers. Slow-release fertilizers have not been widely used in bare root tree seedling nurseries and Christmas tree production. The lack of research in this area causes growers to sometimes guess at fertilizer applications, which can result in economic losses and environmental degradation. Several kinds of slow-release fertilizers are being manufactured and used in the turf industry rather successfully. Polyon-coated slow-release fertilizer trials were introduced in the state bare root nursery in spring 1999. The feasibility of slow-release efficient fertilizer use and prevention of groundwater contamination was compared with conventional fertilizer use. Monitoring input of nutrient added as fertilizers and losses of nutrient in leachates indicated lower losses in slow-release fertilizer beds compared to conventional fertilizer beds. However, the uptake of nitrogen and morphological characteristics of 1+0 white pine seedlings were similar in the conventional and the Polyon-coated slow-release fertilizer plots. The goal of a soil fertility program is to maintain nutrient levels that will optimally suit the needs of the seedlings. We have confirmed that slow-release fertilizers added in lower amounts can yield trees comparable to those obtained with conventional fertilizer and can provide better ground-water protection.

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Author(s): Jaya G. Iyer, Jaslyn J. Dobrahner, B. Lowery, J. M. Vande Hey

Publication: National Nursery Proceedings - 2000

Event: Northeastern Forest and Conservation Nursery Association Conference
2000 - Spring Green, WI