Production of Organic Liquid Fertilizer from Agricultural Waste and their Evaluation on Growth Parameters of Cowpea (Vigna unguiculata (L.)Walp.)

Abstract

Organic liquid fertilizers (OLF) are made up of essential plant nutrients that assist in plant growth and development and serves as a faster means of nutrients assimilation by plants. The purpose of this study was to determine the macronutrient content of organic liquid fertilizers and commercial liquid fertilizer and evaluate their growth performance on cowpea (Vigna unguiculata (L.)Walp.). Market wastes also known as vegetable wastes, cow dung and poultry faeces were utilized to produce organic liquid fertilizer and compare it to commercial liquid fertilizer. The fermentation ratios used for production of the liquid fertilizer were; 5kilograms of vegetable wastes, 3 kilograms of cow dung, 3 kilograms of poultry faeces and 15litres of water. The parameters determined in this study on OLF include; the nitrogen (N), phosphorus (P) and potassium (K). The OLF and commercial liquid fertilizer showed the ranges of pH values as 6.3 and 6.0 and electrical conductivity of 0.7 and 0.8. The chemical analysis results showed poultry faeces plus vegetable waste had the highest content of N(2.00%) while cow dung plus vegetable waste had the highest contents of P(1.73%) and K(3.30%) while plain vegetable waste had the highest calcium content of (3.10%) and magnesium content (0.30%) respectively. The results for the growth parameters showed that OLF made from the combination of vegetable wastes and either cow dung or poultry faeces demonstrated the best growth performance. The organic liquid fertilizers were produced after 40 days of fermentation and used at a dilution of 1:10. Thereafter, complete random designs were setup to monitor the growth performance of cowpea for two weeks. This study showed that organic liquid fertilizer produced was more effective than commercial liquid fertilizer.

Keywords: Agricultural waste, Cowpea, Organic liquid fertilizers.