EVALUATION OF COMPOSTED CABBAGE (Brassica oleracea L.) AS A PLANT GROWING MEDIA FOR HORTICULTURAL PRODUCTION

Abstract

The high costs and limited availability of conventional plant-growing media in Zambia and sub-Saharan Africa pose significant barriers to sustainable horticultural production. This study evaluates composted cabbage waste as a cost-effective and sustainable alternative for horticultural crop cultivation. Experiments at Mulungushi University, Zambia, compared composted cabbage with commercial Hygromix-Poliprop using cabbage, cucumber, tomato, and green pepper as test materials. Composted cabbage substantially increased emergence rates in cabbage (94.44%) and tomato (87.5%), while commercial media were more effective for cucumber and green pepper. The sequence of crop emergence favoured composted cabbage, with cabbage emerging first, followed by cucumber, tomato, and green pepper, suggesting favourable conditions for early establishment. Composted cabbage also improved biomass accumulation, with cabbage showing the highest dry matter accumulation (51.39%) in the composted media, indicating its potential to support robust growth and productivity. Root length and seedling vigour exhibited similar trends, with composted cabbage benefiting cabbage and tomato. A benefit-cost analysis yielded a cost-benefit ratio of two (2) for composted cabbage. These findings demonstrate that composted cabbage is a viable and sustainable alternative to commercial media for certain crops, supporting the circular bioeconomy through agricultural waste recycling. Further research should refine composting processes and investigate broader applications to enhance its utility as a universal growth medium.