As the world’s population exponentially grows, more food production is required. This increasing food production currently has led to the un-sustainable production of chemical fertilizers and resultant overuse. A more sustainable option to enhance food production could be the use of fertilizer derived from food waste. To address this, we investigated the possibility of utilizing a fertilizer derived from food waste to grow hydroponic vegetables. Arugula (Eruca sativa) ‘Slow Bolt’ and lettuce (Lactuca sativa) ‘Cherokee’ and ‘Rex’ were cultivated using indoor deep-flow hydroponic systems at 23 ºC under a photosynthetic photon flux density of 170 µmol∙m−2∙s−1 with an 18-hour photoperiod. Plant nutrient solutions were provided by food waste fertilizer or commercial 15:5:20 NPK fertilizer at the identical electrical conductivity (EC) of 2.3 mS·cm–1. At the EC of 2.3 mS·cm–1, chemical fertilizer contained 150 ppm N, 50 ppm P, and 200 ppm K, while food waste fertilizer had 60 ppm N, 26 ppm P, and 119 ppm K. Four weeks after the nutrient treatments were implemented, compared to plants grown with chemical fertilizer, lettuce ‘Rex’ grown with food waste fertilizer had four less leaves, 27.1% shorter leaves, 68.2% and 23.1% less shoot and root fresh weight, respectively. Lettuce ‘Cherokee’ and arugula grown with food waste fertilizer followed a similar trend with fresh shoot weights that were 80.1% and 95.6% less compared to the chemical fertilizer, respectively. In general, the magnitude of reduction in the plant growth was greatest in arugula. These results suggest that both fertilizers were able to successfully grow lettuce and arugula, although the reduced plant growth with the food waste fertilizer in our study is likely from a lower concentration of nutrients when we considered EC as an indicator of nutrient concentration equivalency of the two fertilizer types.
Managed Aquifer Recharge is an increasingly prevalent solution to sustain water availability in arid regions. Recharge of groundwater resources using treated wastewater effluent is one type of managed aquifer recharge that offers long-term sustainable water management. However, there are some concerns regarding the reuse of wastewater and its potential to increase exposures to antibiotic resistant bacteria and antibiotic resistance genes that could affect human health. Antibiotic resistance genes can confer the ability for bacteria to resist antibacterial treatment, rendering their presence in water supplies as an area of research needed to evaluate where environmental “hot spots” of potential antibiotic resistance disseminate. To evaluate the occurrence of antibiotic resistant bacteria and antibiotic resistance genes, sampling of an Arizona managed aquifer recharge facility was performed, with target antibiotic resistance genes measured using quantitative polymerase chain reaction. The occurrence of antibiotic resistance genes was evaluated at several sampling wells and in sediments to examine trade-offs between water quantity benefits and water quality issues. The goal of this work is to inform management operations for secure water quality in the face of climate change.
Precise addition of agricultural inputs to maximize yields, especially in the face of environmental stresses, becomes important from the financial and sustainability perspectives. Given compounding factors such as climate change and disputed water claims in the American Southwest, the ability to build resistance against salinity stress becomes especially important. It was evaluated if an algal bio-fertilizer was able to remediate salinity stress in Solanum Lycopersicum. A hydroponic apparatus was employed, and data from Burge Environmental’s MiProbes™ both were able to demonstrate remediation. Future research could include determining the minimum dosage of algal fertilizer sufficient to induce this result, or the maximum concentration of salt that an algal treatment can provide a protective effect against.
In the Southwestern United States, climate change poses challenges to reliable water access due to droughts, wildfires, and urban development. Arizonan farmers are faced with unpredictable precipitation, muddled legal water rights, and outdated equipment to irrigate their land. Located in Northern Arizona, Verde Valley residents and stakeholders are challenging the way the Verde River water is managed through collaboration, partnerships, and technical changes to water infrastructure. Through interviews conducted with various stakeholders involved in the Verde River ditch irrigation system, ranging from water users to nonprofit organizations, this paper identifies sociotechnical tinkering as an important aspect of maintaining agricultural operations along the river amid political tensions, social relations, and climate change. Through interviews and analysis, this paper further contributes to the relatively new discourse on the concept of sociotechnical tinkering by proving its existence and its subsequent effectiveness in the Verde Valley. Using statements made by respondents, the paper argues that sociotechnical tinkering helps manage resources through political and social relations.
