Achieving closure of nutrient delivery systems for greenhouse crops: a problem worthy of a solution

摘要

In Europe, legislation is in place for mandatory zero run-off of hydroponic solutions from greenhouses by the year 2000. It is clear that the complete, recycling of greenhouse nutrient solutions is a highly desirable goal, and it is likely that sooner, rather than later, Canadian growers will be faced with more stringent legislation than was in place in the past. It is painfully clear that, for a number of our most valuable greenhouse crops, achieving complete cycling for nutrients will affect the costs of production. It is unclear whether over repeated cropping cycles, it is possible in all cases to achieve complete closure.