TECHNICAL EQUIPMENT IN SOILLESS PRODUCTION SYSTEMS

Technical innovations in fertilization and irrigation have resulted in adoption of fertigation technologies wherein completely soluble fertilizers are dissolved in irrigation water so as to deliver to plants the nutrients they need for optimal growth. This chapter focuses on the technical equipment associated with fertigation and irrigation in greenhouse production. In most such soilless production systems, fertilization is accomplished through injection of soluble fertilizer into irrigation water. It also demonstrates which system is best suited to which crop and where continued innovation is likely to result in future technical advances. In all modern production systems, fertilization and irrigation have been integrated into a system that the grower seeks to optimize. Traditionally growers applied dry fertilizer products to the top of the root zone, resulting in fertilizer nutrients being carried to the root surfaces with the applied irrigation water. Once it was realized, through repeated experiments, that all essential fertilizers could be supplied through completely soluble fertilizer salts, systems were developed where such salts are dissolved at relatively high concentrations in special stock solutions. By using one or more injectors, such concentrated solutions could be injected into the irrigation water (fertigation), a method which is prevalent today.