Flexible films fabricated from biodegradable polymers (biopolymers) show great promise as innovative and sustainable tools in agriculture. Effective farming of high yield and quality cash crops is frequently challenged by drought and water scarcity, especially in south-west Australia, which can have significant economic and environmental impacts. Improving water use efficiency for broadacre cropping can be achieved by capturing and/or directing rainwater (e.g., into furrows), reducing soil-water evaporation rate as well as improving plant-water transpiration rate. However, current technologies used to address these challenges are not sustainable, economically viable nor possess adequate functionality (e.g., polyethylene mulch films). Our novel SMART SPRAY technology uses functionalized, biodegradable polymers and a water-based formulation to improve water use efficiency for broadacre cropping. Using green chemistry principles, biopolymer films with different chemical functionalities were designed and tested for their compatibility, stability and performance under varying environmental conditions. Comprehensive characterization (e.g., chemical, physical and mechanical) of the films was undertaken and compared to target performance outcomes. Laboratory results indicate that sustainable and economically viable biopolymer films can be effectively used to improve water-use efficiency. Further, this suggests that biopolymers can be functionalized to achieve optimum performance outcomes for agriculture. (e.g., slow-release fertilizers, functional sprays), as well as other in prominent industries (e.g., food packaging).