A CONTROLLED-RELEASE NANO-FERTILIZER SYSTEM FOR IMPROVING PHOSPHORUS UPTAKE AND ROOT DEVELOPMENT IN PADDY SOILS

Abstract

The effective management of phosphorus—a critical but often limited nutrient in paddy cultivation—is essential for sustainable rice production. This study aimed to develop and evaluate a controlled-release nano-fertilizer system using nano-hydroxyapatite encapsulated with nanochitin to enhance phosphorus uptake and root development in paddy soils. A randomized complete block design (RCBD) field experiment was conducted with three treatments: T1 (conventional phosphorus fertilizer), T2 (bulk hydroxyapatite), and T3 (nano-hydroxyapatite with nanochitin). The results demonstrated that T3 significantly improved soil phosphorus availability, microbial biomass phosphorus, and phosphorus uptake in shoot and root tissues. T3-treated plants exhibited superior root morphological traits, including increased root length and surface area, along with enhanced phosphorus use efficiency (PUE), which peaked at 74% compared to 42% and 56% in T1 and T2, respectively. Biomass yield and plant vigor were at their highest when plants were treated with nano-fertilizers, seen through their sun-seeking posture, more extended leaves and better overall color from chlorophyll. Because phosphorus was released steadily from the nano-formulation, plants used it as needed, little was lost and the environment benefited. The application of nanochitin promoted good activity of beneficial microorganisms in the rhizosphere and contributed to soil nutrition and health. All these findings suggest that controlled-release nano-fertilizers hold great potential to improve rice farming, increase what crops gain from fertilizers and keep the system sustainable. These results make it easier for farmers to try nanotechnology methods specific to their land and farming needs.