N, P and K content in non-soil planting media for pakchoy (Brassica rapa L.) cultivation in vertical circulation system of aquaponics

Abstract

This study attempts to integrate freshwater fish aquaculture with vegetable cultivation by using agricultural waste as planting media. It is expected that environment friendly technology will be developed for integration of pak choy cultivation and freshwater catfish production (Clarias sp.). The aims of the study are to determine the types of organic planting media and aquaponics watering system that is able to provide sufficient nutrients to the integrated agriculture system. Four organic materials from agricultural wastes e.g. shavings woods, coconut husk, coconut shell biochar and coffee shell biochar were used for growing media. Two aquaponic watering systems with catfish rearing were combined with the organic materials as planting media in a factorial randomized block design of experiment. Addition of organic materials into growing media of pak choy is necessary in the aquaponic system because besides make the media better texture, they also provide nutrients to the plant, particularly the phosphorus. Between the organic materials, coconut shell biochar was high content in phosphorus, while coffee shell biochar in potassium. The experiment also concluded that water circulation has no effect on the nutrition concentration in the aquaponic system.