The use of chemical fertilizers has significantly increased crop yields but has also led to soil problems such as nutrient imbalance and salinization. In response, organic fertilizers have emerged as a crucial component for sustainable agricultural development. This study was designed to develop an easily applicable organic suspension fertilizer using peanut bran, the primary by-product of peanut oil extraction, as the main raw material. Fourier-transform infrared (FTIR) analysis revealed that 80 °C is the optimal heating temperature for forming a stable peanut-bran suspension. A comprehensive experimental investigation was conducted to evaluate the effects of different peanut bran addition levels, stabilizers, emulsifiers, and suspending agents on the stability of suspension fertilizers. The results identified the optimal suspension fertilizer formulation as comprising 20% peanut bran, 0.5% sodium bentonite, 0.1% monoglyceride, 0.2% sucrose ester, 0.02% carrageenan, and 0.3% xanthan gum. This formulation ensures good stability and fluidity of the suspension fertilizer while maintaining a low cost of 0.134 USD·kg⁻¹. The findings provide a scalable technological framework for valorizing agro-industrial waste into high-performance organic fertilizers.

This study evaluates the feasibility of utilizing suspension fertilizers as alternatives to conventional organic fertilizers in drip irrigation systems. The investigation focused on several key aspects, including storage stability, particle size distribution, soil organic matter (OM) content, seed germination, and nutrient utilization efficiency. Suspension fertilizers maintained excellent storage stability, with no stratification or deterioration observed over prolonged storage (≥ 30 days). Their particle size distribution remained suitable for drip irrigation systems, ensuring uniform application and reducing clogging risks. The application of suspension fertilizers significantly increased soil OM content across different soil layers (5–20 cm depth) by 25.3 to 44.1%. The phosphorus-use efficiency of banana seedlings increased 9.1- to 12.6-fold relative to the control. The germination index of cucumber and radish seeds improved by 41.7 to 184.6%. The results demonstrate that suspension fertilizers are a viable alternative to traditional organic fertilizers in drip irrigation systems. They enhance soil fertility, promote seed germination, and improve nutrient utilization efficiency. Future research should focus on long-term field trials to validate these benefits across diverse agricultural settings and soil types.