Skip to main content

Master of Environmental Science and Management: Master's Group Project

Evaluating the Viability of Cyanobacteria-Based Biofertilizers as an Alternative to Synthetic Fertilizers

Group Members: Merina Addonigio , Betty Cheong, Jenna Leonard, Kelly Perymon, Zoe Rennie

Faculty Advisors: Bruce Kendall

Client: The Limoneira Company




Synthetic nitrogen fertilizers increase land productivity as nitrogen, phosphorus, and potassium contained in fertilizers react with the soil to provide nutrients for plants and life. However, there are many negative impacts from the production and application of synthetics. The production of synthetic fertilizers requires large inputs of energy sourced from fossil fuels, such as natural gas (Bicer et al., 2016). Nitrogen oxides (NOx) are released during fossil fuel combustion and react in the atmosphere, creating ozone, a major pollutant that affects human health and terrestrial ecosystems (UNEP and WHRC, 2007). Excess nitrate in surface water causes algal blooms, depleting the water of oxygen and limiting the ability of fish to survive in the waters (Kumar and Sekaram, 2014). Nitrate in groundwater leads to complex human health issues, as human consumption of nitrates can lead to digestive and respiratory failures (UNEP and WHRC, 2007).

To address these concerns, our project will explore and evaluate the potential of cyanobacteria biofertilizer as a source of nitrogen, phosphorus, and potassium for lemon trees at Limoneira, an agribusiness located in Santa Paula, California, that manages 10,600 acres of citrus and avocado trees (Limoneira, 2023). The goal of this investigation is to explore and compare the environmental impacts of the life cycles of synthetic fertilizers and cyanobacteria biofertilizers and provide best management practices to assist Limoneira in reducing its overall environmental footprint. We will be assessing life cycle impacts using the Environmental Protection Agency’s Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI) to provide a comprehensive assessment of the environmental and human health implications. We will leverage the Water Risk Filter tool from the World Wildlife Fund to assess water-related basin risk and operational risk scores. These risks encompass physical, reputational, and regulatory aspects. By evaluating the risk scores alongside life cycle assessment outputs, we aim to enrich the interpretation of our findings and provide comprehensive recommendations for Limoneira.

arrow up icon