An organic and environmentally friendly growing system for greenhouse tomatoes

Greenhouse tomatoes were grown in open beds, confined beds, or in a new system of combined beds. The growing medium and fertilizer consisted of composted deep litter, peat, and hay of a mixture of clover and ryegrass. In the open beds, plants were grown in this compost slightly incorporated into the top soil. In the confined beds, plants were grown in compost placed on wheat straw. The combined beds were identical to the confined beds except for holes in the vertical sidewalls of the container, which enable the roots to grow out into the soil. Plants grown in confined and combined beds produced the earliest yield. Approximately 18% of the fruits produced in the confined beds, developed blossom end rot. Plants grown in combined beds produced the highest yield, whereas those grown in confined beds produced the lowest. This yield reduction and the problems with blossom end rot were caused by a high ion activity ratio a(k)/root a(Mg)+a(ca) in the root zone of the confined beds. Besides high yield, this experiment showed that the new system of combined beds reduced the risk of nutrient losses due to leaching especially when supplemental fertilizer was applied.