Nutrient content of different plant extracts as an alternative to animal manure

Abstract

A research was conducted to assess the nutrient content of three plant extracts made from Weed redroot (Amaranthus retroflexus), Water Hyacinth (Eichhornia Crassipes), and Tithonia (Tithonia diversifolia) compared to cattle manure. The plant extract fertilizers were made by shredding plant materials and fermenting them in water for 4 weeks at the Soil Analytical Laboratory, Makerere University. Plant extract and animal manure samples were analysed weekly for nitrogen, phosphorus and potassium (NPK) for a period of four weeks. Results showed that all plant extracts had higher P and K contents than animal manure suggesting their potential as alternatives to animal manure. However, the Amaranthus plant extract had the highest N (0.36%), P (0.042%) and K (4.286%) contents indicating its suitability as a source of macro nutrients compared to animal manure. It was also noted that the nutrient content increased from week 1 to week 4 of fermentation with the highest nutrient contents recorded at week 4 suggesting fermentation of at least 4 weeks. In conclusion, all liquid manures had relatively higher N, P and K contents than ordinary cattle manure used by small holder farmers in Uganda and thus should be used as an alternative to animal manures for soil fertility management.