6. Plants in aquaponics
This chapter discusses the theory and practice needed for successful plant production in aquaponic systems. First, it highlights some of the major differences between ground-grown crop production and soil-less crop production. Following this, there is a discussion on some essential plant biology and plant nutrition concepts, focusing on the most important aspects for aquaponics. After, there is a brief section on recommendations for selecting vegetables to grow in aquaponic units. The final two sections cover plant health, methods to maintain plant health, and some advice on how to make the most of the plant growing space.
In many commercial aquaponic ventures, the vegetable production is more profitable than the fish. However, there are exceptions, and some farmers earn more from particularly valuable fish. Estimates from commercial aquaponic units predominantly in the West suggest that up to 90 percent of the financial gains can come from plant production. One reason is the fast turnover rate of vegetables compared with the fish.
Further information on aquaponic plant production is covered in Chapter 8 and in the appendixes. Chapter 8 discusses practices to manage plant production through the seasons, and discusses different approaches for each of the hydroponic methods (media bed, NFT and DWC). Appendix 1 is a technical description of 12 popular vegetables to grow in aquaponics; Appendix 2 contains descriptions and tables detailing several organic treatments of pests and diseases.