Formulation and Efficacy Testing of Nano-Biofertilizers in Reducing Chemical Fertilizer Dependence

Abstract

Chemical fertilizer overuse in Pakistan’s wheat systems has led to low nutrient use efficiency, soil degradation, and rising input costs, while conventional biofertilizers suffer from poor storage viability and rapid field decline. This study developed and evaluated a chitosan-zinc oxide nanocomposite encapsulated multi-strain PGPR nano-biofertilizer to reduce chemical NPK dependency without yield penalty. The formulation was synthesized by ionic gelation and characterized for particle size, zeta potential, encapsulation efficiency, and release kinetics. Field and pot efficacy was tested in wheat using a randomized complete block design with seven treatments: absolute control, 100% recommended NPK, unencapsulated PGPR, nano-biofertilizer alone, and nano-biofertilizer combined with 75%, 50%, and 25% of the recommended NPK. Data collected included germination, growth, yield, nutrient uptake, apparent nitrogen use efficiency, grain zinc, and rhizosphere PGPR population. Statistical analysis used ANOVA, Duncan’s test, and regression to link formulation quality to agronomic performance. The nanoparticles ranged 150-280 nm with zeta potential +25 to +35 mV and encapsulation efficiency of 72-80%. Release followed a controlled, non-burst profile over 120 hours. Storage stability was markedly higher than free-cell inoculant, with only a one log cycle decline over 90 days. Agronomically, nano-biofertilizer plus 75% NPK produced grain yield, biomass, and nutrient uptake statistically comparable to 100% NPK, demonstrating a viable 25% fertilizer reduction. Nano treatments also increased grain zinc and maintained rhizosphere PGPR populations above 106 CFU/g through anthesis, whereas free cells declined rapidly. Encapsulation efficiency correlated positively with yield.

The results support nano-biofertilizers as a practical tool for sustainable intensification in wheat, reducing input cost and environmental losses while improving nutrient efficiency. Multi-season validation and techno-economic assessment are recommended for scale-up.

Keywords: Biofertilization; Nanotechnology; Efficiency of Nano- Biofertilization

Citation

Adeel Asghar. Formulation and Efficacy Testing of Nano-Biofertilizers in Reducing Chemical Fertilizer Dependence. WebLog J Nanomed Nanotechnol. wjnn.2026.i1201. https://doi.org/10.5281/zenodo.22839854