SUSTAINABLE CABBAGE PRODUCTION IN KENYA USING OBLIGA BONACRAFT BIOFERTILIZER

Cabbage (Brassica oleracea var. capitata) is a vital crop for Kenyan smallholder farmers, contributing to food security and income. However, declining soil fertility and reliance on costly synthetic fertilizers pose significant challenges. This study aimed to evaluate the efficacy of OBLIGA BONACRAFT P20S10, a microbiological phosphorus-sulfur fertilizer, as a sustainable alternative. Field trials were conducted in four agroecological zones: Kiambu, Kirinyaga, Machakos, and Murang'a, using a randomized complete block design (RCBD) with three replications per site. The experimental plots (12 m?) received BONACRAFT P20S10 at 150, 200, and 250 kg/ha, compared against a standard fertilizer program (RFP) and an untreated control. Growth parameters such as plant height, stem diameter, and head width were measured biweekly. Data analysis focused on determining the optimal application rate and its impact on yield and soil health. Results showed that BONACRAFT P20S10 significantly enhanced cabbage growth and yield, with the 250 kg/ha rate achieving the highest yield (83.4 tons/ha) in Kirinyaga. This study demonstrates the potential of the biofertilizer as a cost-effective, sustainable solution for improving cabbage production while addressing soil degradation and environmental concerns.