Agriculture is one of the more widespread users of synthetic chemicals than any other production sector. The green revolution, which ensured food security, unintendedly affected soil health and the environment. The overuse of synthetic chemicals, especially phosphorus, to meet the global demands have steered agriculture toward a fertilizer-dependent soil. Concurrently the natural soil tends to lose its physical and biochemical properties due to acidification, reduced soil organic matter content, the decline in the microbial interaction, and increased pest activity which questions the sustenance of modern agriculture. The exploitation of electrochemical sensors to measure soil parameters has been recognized as a viable tool in engineered, precise agricultural systems. In this study, highly selective compound molybdenum oxide coupled with reduced graphene oxide (rGO) is used to functionalize the screen-printed electrode (SPE) to achieve excellent selectivity and sensitivity of phosphate ions: Mo_mO_n^z- + HPO₄^2-→ P_lMo_m1O_n1^z1-. The rGO facilitates efficient charge transport for better conductivity of the SPE. The nanocomposite electrode shows improved sensitivity and selectivity toward phosphate ions than the unmodified one. The enhanced charge capacity is achieved, and the electrochemical current output can reach the microampere level per micromole concentration. By engaging the highly specialized devices in agriculture, more precise fertilization can be achieved without degrading the soil health for a sustainable future.