Light Spectra Optimization in Indoor Plant Growth for Internet of Things

Abstract

This paper evaluates three plant grow light spectra suitable for indoor planting for Spinacia Oleracea (Spinach) and Lactuca Sativa (Lettuce). Indoor plant growing chambers and three commercial plant grow lights in the Red, Red-Blue and Yellow spectral range were used. Temperature, humidity and soil moisture were recorded. The spectral range of the grow light was found to affect the temperature, humidity and soil moisture, hence also affecting plant growth. Red light was found to be more suitable for spinach and red-blue light was found to be more suitable for lettuce. A system design allowing control of the spectral range by selection of the appropriate LED's based on the plant needs using the Internet of Things was developed. Future work will implement and test this feature together with other semi-automated plant growth systems such as irrigation and light intensity.