Production and Evaluation of a Forest Litter and Jatropha curcas Cake-Based Biofertilizer Developed through Anaerobic Fermentation

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Résumé

The excessive use of chemical fertilizers leads to soil degradation and water pollution. Microbial biofertilizers have gained attention for promoting sustainable agriculture while protecting the environment. Fermented Forest Litter (FFL) is an organic fertilizer made by fermenting solid agricultural residues under anaerobiosis. It contains diverse microbial communities that can enhance plant growth. This study aims to evaluate the potential of FFL supplemented with Jatropha curcas cake. To achieve this, FFL mixed with Jatropha cake was produced through solid-state fermentation and then activated by submerged fermentation. The chemical and microbiological properties of FFL and Non-Fermented Substrate (NFS) were analyzed. A germination test was conducted on tomato, okra, and maize using activated FFL (aFFL). Before fermentation, NFS had a pH of 6.38, an electrical conductivity of 2.53 mS/cm, 241 mg/kg ammonium, 672 mg/kg soluble phosphorus, 582 mg/kg nitrate, and 4662 mg/kg soluble potassium. FFL had a pH of 4.35, an electrical conductivity of 4.64 mS/cm, 1948 mg/kg ammonium, 2003 mg/kg soluble phosphorus, 66 mg/kg nitrate, and 4864 mg/kg soluble potassium. FFL showed no presence of coliforms or Salmonella . At a concentration of 2%, aFFL improved the germination index of okra, tomato, and maize, with respective values of 429%, 92.5%, and 127.6%. These results suggest that fermented forest litter supplemented with Jatropha curcas cake has promising potential as a biofertilizer.

Mots-clés

Biofertilizer, Solid-State Fermentation, Jatropha curcas , Seed Cake