Effects of Microwave Irradiation (MWI) on Quality of Vermicasts, and Growth of Kale (Brassica oleracea var. sabellica) Plants

Abstract

The application of microwave irradiation (MWI) technique has gained considerable attention in agriculture such as its use to enhance soil properties and extraction of active principles in natural products. It was therefore hypothesized that variables such as MWI power output levels, duration of exposure, and moisture content (MC) of vermicasts may different influence the quality and efficacy of vermicasts. Thus, the present study evaluated the main and the interaction effects of MWI power output levels (0-1000 W), exposure time (0-10 min) and vermicasts moisture content (35-85%) on physical and electrochemical properties, and the efficacy on potted kale (Brassica oleracea var. sabellica) plants growth and tissue chemical content. The quality of vermicasts was significantly (P<0.05) affected by MWI power output levels and exposure time at varying MC. It showed that the 85% MC vermicasts treated at 400 W for 2.5 min was the best treatment for vermicasts to promote kale plants growth. Kale plants treated with 35% and 45% MC vermicasts treated at 400 W for 2.5 min had the least growth parameters. Considering that this research was a pot-experiment performed in the greenhouse, there are some limitations to this research. However, it is recommended that further studies should focus on the large-scale field study and how the MWI influence the biological properties of vermicasts.