Investigation of nutrient solution management in hydroponics using organic fertilizer

Abstract

World market prices for chemical fertilizers have increased significantly due to the demand for food in world affairs. According to the 2022 FAO data, Thailand’s domestic use of imported fertilizers rate is about 87.27%. The fertilizers used in Thailand are dependent on imports and may affect food safety. Thus, research on bioponics, a hydroponic system that combines sustainable and organic agriculture, is very effective. Hydroponics is a highly efficient agriculture production, due to extreme weather, water shortages, etc., that allows for artificial control of the environment and indoor vertical cultivation. Bioponics using organic fertilizers can be managed to harvest vegetables earlier by managing the growing environment, balancing the pH, and harvesting healthier vegetables because of the high nutrient content in the water. The objective of this research is to establish an appropriate method of organic fertilizer application in hydroponics, using microorganisms under aerobic conditions. In the organic cultivation of field crops, microorganisms in the soils degrade organic matter to inorganic matter that can be absorbed by plants, but hydroponics use sterilized water from the disease control perspective, so, microorganisms are almost non-existent. Therefore, in this research, a small amount of soil collected from a field was placed in water and aerated, and then a small number of organic fertilizers was added to the water to allow microorganisms to degrade the organic matter into nitrate nitrogen. The preparation process was about 2 weeks. To determine the appropriate concentration rate of organic fertilizer during the preparation period, two containers were used to sample liquid fertilizer during the preparation process and cultivation period to investigate nitrification and microorganisms. In this study, we also cultivated water spinach after the preparation process and collected data on the growth of different concentration factors.