Biodegradable Polymer Nanocomposites Provide Effective Delivery and Reduce Phosphorus Loss during Plant Growth
Leslie R. Sigmon, Ishaq O. Adisa, Beichen Liu, Wade H. Elmer, Jason C. White, Christian O. Dimkpa, D. Howard Fairbrother
Abstract
Although phosphorus (P) is an essential element, its availability to plants is often limited, and P-containing fertilizers must be supplemented to stimulate plant performance. However, the inefficiencies and negative environmental impacts associated with current nutrient delivery strategies have motivated interest in nanotechnology-enabled agriculture. Here, we synthesized biodegradable polymer nanocomposites (PNCs) containing polyhydroxyalkanoate (PHA) and calcium phosphate nanoparticles (Ca–P–NPs) and assessed their efficacy as a P-delivery vehicle, compared to a conventional P source (CaHPO4), using tomato as a test plant. The effectiveness of PHA–Ca–P PNCs was assessed by measuring plant biomass, fruit yield and quality, tissue elemental and chlorophyll content, and enzymatic biomarkers. Phosphorus in the leachate was used as a surrogate for runoff. PHA–Ca–P PNCs biodegraded as a result of microbial activity in the soil, controlling the release of P during the initial stages of plant growth. PHA–Ca–P PNCs supported plant performance comparably to the conventional P source, while significantly reducing the P loss from the soil by over 80%. Given the negative consequences of eutrophication driven by P-rich agricultural runoff, this significant reduction in lost P has broad implications. Our studies also highlight the need to improve the efficiency of P uptake by plants from exogenous P sources. Collectively, these findings demonstrate the significant potential of biodegradable PNCs as a nutrient delivery platform to simultaneously enhance crop productivity and reduce the negative impacts of agriculture on the environment.