|Author: ||A. A. Csizinszky|
|Keywords: ||Bell pepper, Capsicum annuum L., cabbage, Brassica oleracea L. capitata group, cucumber, Cucumber, Cucumis sativus L., dry matter, mineral concentration, micro-(drip-) irrigation|
Three vegetable crops, bell peppers, Capsicum annuum L.; cabbage, Brassica oleracea L., capitata group; and cucumber, Cucumis sativus L.; were grown during the fall-winter-spring (Sep. 1996-June 1997) in sequence in the Earth Box and compared with yields of the same three vegetable crops grown on the same land with the full-bed polyethylene mulch system with micro-irrigation.
Soil in the micro-irrigated plots was the Eau Gallie fine sand.
The ‘Earth Box’, made of recycled plastic, is a 244-cm long, 33-cm high and 40.6-cm wide closed production system.
The bottom, 9-cm deep, compartment contains the water reservoir and is separated from the 24-cm deep soil compartment above it by a perforated plate.
There is no leaching of fertiliser, or water, from the box to the environment.
The boxes were filled with three growth media: 100% soil (EauGallie fine sand) (100% soil); 100% prepared medium mix of peat, sawdust and pine-bark (100% medium); and 50% fine sand: 50% prepared medium (50% medium). Dry fertilisers were banded prior to planting in a narrow, 5-cm groove for the crops (N-P-K in kg.ha-1 equivalent) as follows: bell pepper: 292–35–243; cabbage: 228–0–98; and cucumber: 119–0–82. The top and south side of the boxes were covered with a 0.032 mm thick white on black polyethylene film.
Best yields in the boxes were recorded with the 50% medium treatment.
Marketable yields of cucumbers, with 118 mm irrigation and bell peppers with 288 mm irrigation in the 50% medium treatment were similar to yields in the micro-irrigated plots with 320 mm and 344 mm irrigation, respectively for cucumbers and bell peppers.
Cabbage yields were lower in the boxes than in the micro-irrigated plots.
Very high residual concentrations of total soluble salts (TSS) were measured in the growth media in the boxes after each crop.
Little or no differences were found in leaf elemental concentrations among the treatments.
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