Evaluation of elemental composition and structural analyses of liquid organic fertilizers from rabbit wastes under different feeding regimes

This study aimed at evaluating the elemental composition and structural analysis of liquid organic fertilizers (LOF) produced from rabbit urine and feces under different feeding regimes: forage only, concentrate only, and forage plus concentrate. The rabbit waste was subjected to a three-week fermentation process. The temperature of the rabbit waste treatments decreased over time and remained relatively constant after the first week of fermentation. The LOF from different feeding regimes exhibited high pH, electrical conductivity, and nutrient content, including N, P, Ca, Mg, C, and various micronutrients. Notably, the LOF from rabbits fed forage only and forage plus concentrate had particularly high nutrient levels. In contrast, the heavy metal content of the LOF was very low. For example, the potassium content of LOF (urine only) from rabbits fed forage only was 25.63 mg/L, whereas the LOF from rabbits fed concentrate only contained 5.60 mg/L. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the presence of phenol, carboxylic groups, double and triple bonds of alkenes and alkynes, and NH functional groups in most LOF treatments. This indicates that the LOF has the potential to enhance the nutrient-holding capacity of the soil. In conclusion, the LOF produced from forage-fed only and forage plus concentrate-fed rabbits had liming potential and high nutrient contents, making them suitable for viable crop production. Further field studies are highly recommended to demonstrate the performance of LOF under different feeding regimes on nutrient uptake by plants. Key words: Rabbit urine, liquid organic fertiliser, FTIR, fermentation, forage.