Journal of Agronomy and Field Innovations

Background: Chickpea (Cicer arietinum L.) is the second most widely cultivated grain legume worldwide, and its productivity is strongly constrained by phosphorus (P) deficiency in semi-arid and calcareous soils. Conventional phosphatic fertilizers exhibit low phosphorus use efficiency (PUE) because a large proportion of applied phosphorus is rapidly fixed into insoluble calcium, iron, or aluminium phosphates, rendering it unavailable to roots and contributing to eutrophication of downstream water bodies.
Objective: This study was undertaken to synthesise and characterise a nano-phosphorus (Nano-P) fertilizer and to evaluate its effect on growth, physiology, nutrient uptake, yield attributes, phosphorus use efficiency, and soil health of chickpea relative to the recommended dose of conventional phosphorus (RDP).
Methods: A hydroxyapatite-based Nano-P fertilizer was synthesised by wet-chemical co-precipitation and characterised using SEM, TEM, XRD, FTIR, DLS, and zeta potential analysis. A field trial with six treatments (control, RDP, and Nano-P at 25, 50, 75, and 100% of RDP) was laid out in a Randomized Complete Block Design with three replications. Growth, physiological, yield, and nutrient-uptake parameters were recorded, and soil health indicators assessed at harvest.
Results: The synthesised Nano-P particles were spherical with a mean size of 68 nm and a zeta potential of -24.6 mV, indicating good colloidal stability. Compared with RDP, full-dose Nano-P (T6) significantly increased plant height (18.7%), root nodulation (37.4%), phosphorus uptake (46.2%), grain yield (24.1%), and phosphorus use efficiency (from 14.6% under RDP to 41.3% under Nano-P), while also improving soil available phosphorus and microbial biomass carbon at harvest (P <= 0.05).
Conclusion: Nano-phosphorus fertilization substantially improves phosphorus use efficiency, plant growth, and yield in chickpea while enhancing soil biological health, offering a scientifically sound and environmentally sustainable alternative to conventional phosphatic fertilizers for climate-smart legume production.