Production and characterization of liquid bio-fertiliser from orange peels, banana peels, and eggshell

The research focused on the production of liquid biofertiliser to answer challenges in the area of nutrient release and poor microbial activity in conventional biofertiliser, to respond to these inquiries, the biofertiliser is produced by drying banana peels, orange peels, and eggshells at 60 °C, and it undergoes reduction at 100 μm, and further blended in an optimal proportion using design of experiment (CCD). After sterilization at 100 °C for 10 min, the mixture was allowed to ferment at 37 °C for 744 h with the pH adjusted to 6.0–7.5. Pseudomonas and Bacillus strains were also introduced as inoculants. The investigation based on proximate analysis showed that the phosphorus content of eggshells. Banana peel and orange peel was 0.8, 1.2, and 0.7%, the potassium content of banana peels, orange peel, and eggshell was 3.0, 2.1, 1.57%, while the nitrogen content of orange peels, eggshell, and banana peel was 0.9, 0.01, 1.57% this shows the promising nutrient profile for biofertiliser production. The optimal mixture consists of 57.3 wt.% of banana peel, 32.10 wt.% of orange peel, and 10.6 wt.% of eggshell. This formulation resulted in a biofertiliser containing 1.30% nitrogen, 3.45% phosphorus, and 1.52% potassium, along with high microbial counts of Pseudomonas and Bacillus. The liquid biofertiliser was further introduced into different soil types (sandy, loamy, clay). To improve soil conditions. In sandy soil, the pH increased from 6 to 6.5, likewise, there was an observed increase across all the nutrient levels of nitrogen, phosphorus, and potassium. Comparable positive results remained observed in loamy and clay soils, and an increase in microbial activity and nutrient content. These findings show the importance of using banana peels, orange peels, and eggshells in the formulation of liquid biofertiliser which can improve soil health, enhance crop output, and support sustainable farming practices.