Improving pea quality with vermicompost tea and aqueous biochar: Prospects for sustainable farming in Southern Africa

Abstract

One of the main factors responsible for successful sustainable food production is vigorous seedling establishment. The role of organic extracts (vermicompost tea and aqueous biochar) on improving seed performance has not been fully explored in South Africa. Pea seed germination and emergence experiments using different concentrations of organic extracts were conducted according to International Seed Testing Association (ISTA) rules, and arranged in completely randomised block designs with four replications. Vermicompost tea (VC) significantly improved seed germination and emergence percentages, speed of germination and emergence, and physiological processes compared with biochar (BC) and vermicompost tea with microbial supplements (augmented). In contrast, biochar improved seedling growth by 39% compared to vermicompost tea. Application of the BC and VC extracts led to a 12% and 18% increase in pea germination percentages respectively. Similarly, BC and VC extracts at 10% concentration were effective in yielding optimal photosynthetic responses. The 5% and 10% VC, or 2.5% BC extracts are recommended for improving speed of germination, optimal germination and emergence percentages of pea seeds. Application of these extracts will be beneficial for resource-poor farmers in marginal lands, since these organic extracts are cheaper, easier to produce and more environmental friendly than the available commercial fertilisers. This study has shown that vermicompost tea provides essential nutrients for pea seed establishment, thus negating the need to use chemical fertilisers for effective seedling establishment.