Integration of Urine-Charged Biochar and Chemical Fertilizers Enhances Cauliflower Productivity in Inceptisols

Cauliflower (Brassica oleracea var. botrytis) cultivation in Nepal relies heavily on chemical fertilizers, degrading soil microbes and causing nutrient imbalances. Judicious organic-inorganic fertilizer use is vital for sustainable yields. A field experiment was conducted in Rampur, Chitwan, Nepal, (November-February 2019) to evaluate the effects of urine-charged biochar (UCB) and recommended dose of chemical fertilizers (RDF) on growth and productivity of cauliflower in Inceptisols. The experiment followed a Randomized Complete Block Design (RCBD) with six fertilizer treatments: control (no fertilizer), UCB 100%, RDF 100%, and their combinations (UCB 75% + RDF 25%, UCB 50% + RDF 50%, UCB 25% + RDF 75%), replicated four times. Lantana camara biochar, produced via low-cost Kon-Tiki slow pyrolysis, was mixed with cattle urine (1:1 w/w) and applied to the root zone. Plant height, leaf number, canopy diameter, stem weight, root length, root weight, and yield differed significantly (p<0.05) among treatments. The UCB 50% + RDF 50% treatment produced the highest yield (47.3 Mt ha-1) and biological yield (92.35 Mtha-1), surpassing RDF 100% by 24.9% (yield) and 14.9% (biological yield), and UCB 100% by 9.8% (yield) and 7.0% (biological yield). The experiment demonstrates that combined UCB and chemical fertilizer application enhances cauliflower yield and yield attributes compared to sole applications.