Development of an inexpensive and simple fertilizer method using plastic bottles with a semipermeable membrane for seaweed cultivation

Abstract

An inexpensive and simple fertilizer application tool using plastic bottles fitted with a semipermeable membrane was tested in the laboratory and field for enhancement of nori cultivation. In the laboratory test, the amount of permeation of NO₃-N and NH₄-N from the fertilizer in the fertilizer application tools through the semipermeable membrane was continuous and stable. In the experimental cultivation of nori carried out in the Kii channel, Tokushima Prefecture, two areas were set in the nori cultivation system, i.e., an experimental fertilization area with numerous fertilizer application tools and a control area with no application tools. In the fertilization area, the growth and color tone of the nori thalli were better than control area and the Nori product value increased. This result indicates the effectiveness of this fertilizer application tool in the nori cultivation and the possibility of application to cultivation technologies of otheralgae.