13 - Growing Plants in Soilless Culture: Operational Conclusions

Abstract

This chapter presents the facets of soilless plant production, representing the state of the art and including some perspectives on the direction in which the field is moving, to provide practitioners with practical operational tools, allowing them to optimize crop production. It aims to develop a better understanding of the intricate processes taking place within the system along the root zone–plant–atmosphere continuum, as affected by the interactions among the growing substrate, the liquid and gaseous phases held in its matrix, and its nutritional status. The study verifies the concept presented by Mitcherlish, which suggests that plant productivity is limited by the nutritional factor that is limiting. This concept is appropriate if all factors except one are non-limiting. It also holds true in a broader sense when considering all factors that impact soilless crop production. However, when multiple factors are limiting, one must anticipate interacting effects which are more complex than simply suggesting causality of suboptimal production to the most-limiting factor. Finally, the study summarizes that horticultural engineering has significant opportunities in the area of integration of sensor technology with dynamic control over the root-zone variables that are the primary constraints to productivity.