Abstract:
Purpose: Environmental-friendly organic fertilizers reduce the adverse impacts of chemical fertilizers. This study was conducted to formulate organic liquid fertilizers using selected plant materials i.e., Tithonia diversifolia, Mikania scandens, Chromolaena odorata and Gliricidia sepium with selected organic wastes to compare the efficacies of foliar and soil-applications over the growth of leafy vegetables; Basella alba and Centella asiatica.
Research Method: Selected plant materials were allowed to decompose for two months and thereafter fish waste was hydrolyzed separately with fruit wastes of Carica papaya, Ananas comosus and (1:1 w/w) mixture of both were mixed and nutrients analyzed. Fertilizers were foliar and soil-applied separately on C. asiatica and B. alba in RCBD in pot trials.
Findings: Fertilizer formulated with decomposed plants + fish waste hydrolyzed with C. papaya significantly recorded the highest N (0.57%), P (0.06%) and highest growth of C. asiatica and B. alba over both soil and foliar applications followed by the fertilizer formulated with decomposed plants + fish waste hydrolyzed with C. papaya + A. comosus. Foliar-application of B. alba significantly showed the highest growth than the soil-application [shoot height (36.6±3.4 cm vs 30.0±1.5 cm), number of leaves per plant (21.7±1.4 vs 17.5±0.8) and plant fresh-weight (61.5±1.8 vs 55.6±0.9 g)] whereas, C. asiatica indicated no significant difference considering both fertilizer application methods.
Research limitation: Pot experiments were carried out to provide uniform soil conditions for the experiment which was the main limitation compared to field trials.
Originality/value: The formulated novel fertilizers could be utilized effectively in organic farming for safe and healthy leafy vegetables which reduce the adverse impacts of chemical fertilizers.