Sustainable Soilless Recirculating Hydroponics for Productive Use of Marginal Lands: A South African Context

Soilless recirculating hydroponic systems (those in which the nutrient solution is continuously recirculated and reused into the system) are well known for their potential to maximize crop production with minimum inputs of fertilizer and water, resulting in improved yields and quality of fresh produce, as well as increased farmer’s profitability and environmental preservation. The most implemented recirculating hydroponic systems in South Africa include the gravel and nutrient film, ebb-and-flow, and deep-water-culture techniques. Appropriate management and maintenance of these systems are crucial for increased crop productivity and water use efficiency. This is particularly relevant in South Africa for being a food-insecure and water-scarce country. This chapter highlights important production factors in recirculating hydroponics, typical crop yields, and water use efficiency obtained under South African conditions while emphasizing potential focus areas for research to improve the profitability and sustainability of crop production in soilless recirculating hydroponic systems.