Articles
THE PRODUCTION OF STANDARD CARNATIONS ON NUTRIENT-LOADED ZEOLITE
Existing substrate systems for the production of carnations on Jersey include containerised pumice and the traditional peat module, both of which are irrigated with liquid fertilisers throughout the life of the crop.
The use of a modified zeolitic substrate in 5 litre pots was examined using mixtures of reservoir and borehole waters only in the irrigation cycles.
At no time did the carnation plants receive any liquid fertiliser inputs.
Zeolites are crystalline, hydrated aluminosilicates with 3 dimensional crystal structures, which lose and gain water reversibly and can exchange cations without a major change of structure.
The zeolite clinoptilolite shows a preferential absorption for potassium and ammonium-nitrogen.
Twelve standard carnation varieties were selected and 4 cuttings were planted in each 5 litre pot to give a density of 32 plants per square metre.
Analyses completed on the input irrigation water and drain water from the pots showed little differences in nutrient content.
After an initial release of nitrate-nitrogen and phosphorus, the drain water contained low levels of nutrients thoughtout the main growing period.
Leaf tissue analyses performed on fully expanded leaves revealed a significantly lower leaf nitrate-nitrogen content, in comparison to corresponding leaf samples from pumice systems irrigated with liquid feeds.
Yields over a 12 month period are tabulated for a number of commercial standard carnation varieties including ‘Master’, ‘White Giant’, ‘Esty’ and ‘Griselda’.
The experimental work is continuing in an attempt to refine a new crop production system for flower crops and investigate a possible alternative to recirculation of liquid nutrient – supplied substrate systems.