Efficacy of Nano DAP as a supplement to conventional phosphorus and its impact on roots, yield and economics

A field study was conducted in 2022 at the College of Agriculture, Navile, Shivamogga, to assess the effects of conventional DAP and nano DAP seed priming and foliar applications on maize growth, root traits and yield. The experiment followed a Randomized Complete Block Design (RCBD) with 11 treatments, including conventional DAP and nano DAP applications, replicated thrice. The combined application of 75 % of the recommended dose of phosphorus (RDP) with nano DAP seed priming and two foliar sprays resulted in a 5.15 % yield increase over the standard Package of Practice (PoP). However, nano DAP applied solely through seed priming and foliar sprays improved yield by 42.26 % over the absolute control but reduced grain yield by 27.08 % compared to PoP. Despite lower phosphorus usage, the combined nano DAP approach significantly enhanced maize growth, root development, yield attributes and nutrient efficiency over conventional phosphorus treatments. This strategy improved crop performance and promoted sustainable phosphorus management by reducing application rates by 25 %, highlighting nano DAP as a promising alternative to traditional fertilization.