Purpose: Understanding the main factors affecting the environmental impacts of milk production and consumption along the value chain is key towards reducing these impacts. This paper aims to present detailed spatialized distributions of impacts associated with milk production and consumption across the United States (U.S.), accounting for locations of both feed and on-farm activities, as well as variations in impact intensity. Using a Life Cycle Analysis (LCA) approach, focus is given to impacts related to (a) water consumption, (b) eutrophication of marine and freshwater, (c) land use, (d) human toxicity and ecotoxicity, and (e) greenhouse gases. Methods: Drawing on data representing regional agricultural practices, feed production is modelled for 50 states and 18 main watersheds and linked to regions of milk production in a spatialized matrix-based approach to yield milk produced at farm gate. Milk processing, distribution, retail, and consumption are then modelled at a national level, accounting for retail and consumer losses. Custom characterization factors are developed for freshwater and marine eutrophication in the U.S. context. Results and discussion: In the overall life cycle, up to 30% of the impact per kg milk consumed is due to milk losses that occur during the retail and consumption phases (i.e., after production), emphasizing the importance of differentiating between farm gate and consumer estimates. Water scarcity is the impact category with the highest spatial variability. Watersheds in the western part of the U.S. are the dominant contributors to the total water consumed, with 80% of water scarcity impacts driven by only 40% of the total milk production. Freshwater eutrophication also has strong spatial variation, with high persistence of emitted phosphorus in Midwest and Great Lakes area, but high freshwater eutrophication impacts associated with extant phosphorus concentration above 100 µg/L in the California, Missouri, and Upper Mississippi water basins. Overall, normalized impacts of fluid milk consumption represent 0.25% to 0.8% of the annual average impact of a person living in the U.S. As milk at farm gate is used for fluid milk and other dairy products, the production of milk at farm gate represents 0.5% to 3% of this annual impact. Dominant contributions to human health impacts are from fine particulate matter and from climate change, whereas ecosystem impacts of milk are mostly due to land use and water consumption. Conclusion: This study provides a systematic, national perspective on the environmental impacts of milk production and consumption in the United States, showing high spatial variation in inputs, farm practices, and impacts.

Environmental impact associated with production and consumption of pulses in the United States was evaluated using life cycle assessment (LCA). The system boundary was set to cradle-to-grave with a functional unit of 60 g (dry basis) of pulses consumed in a US household. Varieties of pulses modeled in the study included field pea (Pisum sativum), lentil (Lens culinaris), chickpea (Cicer arietinum), and dry bean. Three methods of cooking pulses at the consumer stage tested in the study were cooking in open vessel on electric cooking range (OVC), cooking in stovetop pressure cooker on electric cooking range (SPC), and cooking in electric pressure cooker (EPC). OVC formed the base scenario against which all other scenarios were compared. The environmental impact of pulses varied with type of pulse crop, cooking method, and the batch size. Consumption of approximately 60 g of dry pulses resulted in the greatest environmental impact for OVC. The consumer stage contributed at least 83, 81, 76, 75, and 87 percent for global warming potential (GWP), fossil resource scarcity (FRS), water consumption (WC), freshwater eutrophication (FE), and marine eutrophication (ME), respectively for this scenario. EPC resulted in the greatest decrease in the environmental impact, compared to OVC, for GWP, FRS, FE, and ME for all pulse varieties, which was validated in the uncertainty analysis. SPC, on the other hand, decreased the impact across these categories only for chickpea and dry bean. The uncertainty analysis suggested that the differences associated with cooking methods in the mean land use and water consumption scores of pulses were statistically non-significant. The impact categories were also highly sensitive to the mass of pulses cooked in a batch. Increasing the reference flow in OVC to 1 kg decreased the environmental impact of pulses by 49-87 percent for all impact categories, excluding land use. Overall, the study identified the consumer stage as the hotspot for environmental impact in the supply chain of pulses in the United States. The large contribution of the consumer stage to the overall environmental impact of pulses was attributed to electricity consumption for cooking and associated upstream emissions.

A cradle-to-grave life cycle assessment (LCA) study was conducted for an open-field strawberry (strb) produced in California. The evaluation covered the full supply chain of strawberry, which also included the impacts of food waste generated at each phase of the life cycle. The supply chain included farming, retail, consumption, and end-of-life treatments of waste generated. Data on strawberry farming (included cultivation, harvest and packaging) were collected from the selected farms, with an average strawberry acreage of 138 acres. The defined functional unit (FU) was 1 kg-strb, consumed at the consumer stage, including food waste. Life cycle inventory (LCI) data for post-farm (retail and consumer stage) were based on the available literature and engineering estimates. The ReCiPe 2016 method was used to calculate the potential environmental impacts. The total GHG emissions calculated per FU was 1.45 kg CO2eq; freshwater eutrophication potential was 4.43*10−4 kg Peq/FU, fossil resource scarcity was 0.46 kg oileq/FU. Transportation contributed to about 32% of the total GHG emissions, the use of all forms of plastics (including packaging PET, labels, and field plastics) contributed 18% of the total GHG emissions, while their treatments contributed ∼1% (including the credits from the related recycling process). The use of corrugated boxes contributed 15% of the GHG emissions, while end-of-life treatment provided credits by –7% of the total impact. Food waste treatment contributed ∼15% to the total GHG emissions. For fossil resource scarcity, cultivation along with packaging contributed 71% of the total impact, followed by retail and consumer (25% and 11%, respectively), which was mainly due to transportation. Results showed that the use of recycled packaging materials and the adoption of a suitable recycling process are effective strategies to lower the environmental impacts. The study also showed that with changes in crop yields by ±10%, as compared to the reported yields, most of the selected environmental impacts could change by ± 3–4%, while water consumption would vary by −9% (with +10% yield increase) and increase by 11% (with −10% yield). Reducing food waste by 10% could lower the total GHG emissions by around 1%.

Agricultural production systems have been identified as significant sources of anthropogenic impacts across several environmental key performance indicators (KPIs). Livestock husbandry is growing in global importance as the demand for high-quality protein continues to increase. It is therefore imperative to have sustainable intensification technologies, and we describe one such technology. The purpose of this study was to evaluate the performance of Enogen® corn grain compared to conventional feed corn when used as an ingredient in backgrounding and feed yard beef rations using life cycle assessment. The project was conducted in compliance with ISO standards, including a third-party panel review. A series of scenarios were analyzed to evaluate the impacts of boundaries and functional units on the outcomes. The use of Enogen corn as a feed component in beef production showed a quantifiable benefit in terms of the sustainability metrics of primary interest in this study. The gate-to-gate improvements at the feed yard and backgrounding based on full field trial datasets from field trials conducted at Kansas State University and at the University of Nebraska, Lincoln showed 3.4 and 5.8 percent reductions in Global Warming Potential, respectively. It is particularly noteworthy that the improvement in feed conversion ratio at the feed yard results in approximately 6 percent improvement in the four key environmental performance metrics of beef production, which demonstrates potential for the sector to meet its sustainability targets.

Ammonia removal and disinfection are two major problems in aquaculture systems, which require clean and reliable water to support long-term growth and health of target animals. In this study, we report electrochemical ammonia removal and disinfection of wastewater from an aquaculture farm (Mari?s Gardens) in Hawaii. First, we attempted to reproduce the work of Zollig and co-authors, who reported that direct ammonia oxidation can occur between 1 V and 1.6 V vs SHE on a graphite electrode in a solution (pH = 9.0) containing 1 M NaClO4, 0.25 M NH4ClO4, and 0.085 M NaCl. Our results, however, show that direct ammonia oxidation is unlikely to occur, at least at significant rates, on a graphite electrode in aqueous solutions (pH = 9.0) containing 0.7 M Na2SO4, 0.1 M (NH4)2SO4, and 0.02 M NaCl. We tentatively attribute this discrepancy to the different physico-chemical characteristics of graphite electrodes made by different manufacturers. Second, PtRu/graphite electrodes were prepared using a pulsed electrodeposition method, and electrode activity towards ammonia removal and disinfection was examined in both synthetic and real aquaculture wastewater using batch and flow reactors. The PtRu catalyst was partially oxidized at the beginning of electrolysis, and a significant increase in the electrode activity towards indirect ammonia oxidation was observed. Ammonia removal was slow when NaCl concentration was 0.66 mM, but the addition of NaCl (up to 20 mM) led to a drastic increase in the ammonia removal rate, indicating that ammonia removal proceeds via indirect oxidation. The ammonia removal rate depends primarily on NaCl concentration and current density and is independent of the initial ammonia concentration and solution pH. The ammonia removal rates can be modeled by pseudo zero-order kinetics, and a linear correlation can be drawn between the ammonia removal rate (k, mg L-1 min- 1) and the product of NaCl concentration ([Cl-], mM) and current density (j, mA/cm2): k = 0.0047 [Cl-] j (R2 = 0.99). Free chlorine (Cl2, HOCl, and OCl-) was not detected in the solution until the complete removal of ammonia. Combined chlorine (NH2Cl, NHCl2, and NCl3) was measured at concentrations of 2?15 mg/L (as Cl2) during the ammonia removal process but was eliminated as soon as ammonia was depleted and an excess of free chlorine was available. Our detailed findings on the formation of both free chlorine and combined chlorine are significant to the mechanistic study of indirect ammonia oxidation. Ammonia removal experiments in synthetic and real aquaculture wastewater showed similar results. However, ammonia removal in the flow reactor took about three times longer than that in the batch reactor under similar conditions, likely due to hydrodynamic mixing differences. In addition, it was found that E. coli bacteria can be completely inactivated (5-log reduction) within a short time (e.g., 5 min).

[This corrects the article DOI: 10.1016/j.dib.2020.106639.].

This work reports on the electrochemical disinfection of natural irrigation water collected from the Waiahole Ditch Irrigation System in Hawaii using a batch cell assembled with titanium electrodes as both anode and cathode. Disinfection experiments were performed by applying a polarity-reversing direct current between the two titanium electrodes. The naturally occurring concentration of chloride in the water was 1.84 mg l(-1) and no other chemicals were added. The applied current density was varied between 0 mA cm(-2) and 2 mA cm(-2), and the half-period (T/2) of the polarity-reversing direct current was varied between 5 s and 60 s. The best disinfection performance was achieved at 2 mA cm(-2) and T/2 = 10 s, requiring only 5 min of treatment for the complete disinfection of E. coli (4-log reduction). E. coli was inactivated by free chlorine species electrogenerated at the titanium electrodes. Hydrogen peroxide, short-lived oxidants, and direct electron transfer most likely had minor contributions to the disinfection process. During the disinfection experiments, the concentrations of disinfection byproducts (ClO3 (-), CHCl3, CHBrCl2, CHBr2Cl, and CHBr3) were significantly lower than recommendations for drinking water. The titanium electrodes consumed less electrical energy than platinum-coated titanium electrodes because they needed a lower current density to achieve similar disinfection efficiency.

. Food and agricultural systems (FAS) provide food, feed, fiber, energy, and other products, and they are intricately interwoven with human society. FAS are often misunderstood as simply farming systems. In reality, FAS are much more complex because they encompass a wide range of activities—including production, processing, transport, marketing, and consumption—as well as management of the byproducts. In the U.S., FAS constitute more than 22% of the national GDP, employ more than 28% of the national workforce, and are critical to national security.

White maize in South Africa is the only staple crop produced on a widespread commercial basis for direct human consumption using genetically modified (GM) cultivars. Using a combined economic and environmental approach, we estimate the total welfare benefits attributable to GM white maize in South Africa for 2001-2018 are $694.7 million. Food security benefits attributable to GM white maize in South Africa also manifest through an average of 4.6 million additional white maize rations annually. To achieve these additional annual rations using conventional hybrid maize, the additional land required would range from 1088 ha in 2001 to 217,788 ha in 2014. Results indicate that GM maize reduces environmental damage by $0.34 per hectare or $291,721 annually, compared to conventional hybrid white maize.

Food systems are increasingly challenged to meet growing demand for specialty crops due to the effects of climate change and increased competition for resources. Here, we apply an integrated methodology that includes climate, crop, economic and life cycle assessment models to US potato and tomato supply chains. We find that supply chains for two popular processed products in the United States, French fries and pasta sauce, will be remarkably resilient, through planting adaptation strategies that avoid higher temperatures. Land and water footprints will decline over time due to higher yields, and greenhouse gas emissions can be mitigated by waste reduction and process modification. Our integrated methodology can be applied to other crops, health-based consumer scenarios (fresh versus processed) and geographies, thereby informing decision-making throughout supply chains. Employing such methods will be essential as food systems are forced to adapt and transform to become carbon neutral due to the imperatives of climate change.

This field case study reports findings on disinfection/ammonia removal from aquaculture wastewater and disinfection of irrigation water carried out at an aquaculture farm and two irrigation locations in Hawaii. We used a flow cell incorporating PtRu/graphite anode and graphite cathode for the disinfection/ammonia removal from aquaculture wastewater, and a flow cell assembled with graphite plates as both anode and cathode for the disinfection of irrigation water. The removal of ammonia followed the indirect oxidation mechanism mediated by free chlorine electro-generated at the PtRu/graphite anode. Ammonia removal rate increased with the increase in NaCl concentration, applied current density, or flow rate. The disinfection of aquaculture wastewater can be readily achieved due to the presence of highly germicidal free chlorine species. The disinfection of irrigation water was realized without the addition of chemicals. The disinfection mechanism was attributed to the formation of free chlorine from the anodic oxidation of chloride ions naturally occurring in the water sources. The disinfection efficiency decreased with increasing organic matter concentration. In addition to the flow cell approach, we also successfully demonstrated the disinfection of irrigation water by adding electrolyzed NaCl solution or purging with a mixture of air and chlorine gas, both of which were generated on-site. Practitioner points Field case study on disinfection/ammonia removal from aquaculture wastewater and disinfection of irrigation water was carried out in Hawaii. Electrochemical flow cell assembled with PtRu/graphite anode and graphite cathode effectively removes ammonia from aquaculture wastewater. Ammonia removal proceeds via the indirect oxidation mechanism mediated by free chlorine electro-generated at the PtRu/graphite anode. Electrochemical flow cell assembled with commercial graphite electrodes enables fast disinfection of coliform bacteria and E. coli. The primary disinfection mechanism is through chlorine species electro-generated from chloride oxidation at the graphite anode.

. Corn-soybean rotations are the predominant U.S. cropping system in terms of land area (92 million acres of corn and 84 million acres of soybeans; USDA, 2020), production (346 million tons of corn and 119.5 million tons of soybeans), and economic value ($75 billion from corn and $21.5 billion from soybean). More than 70% of U.S. corn was used for livestock feed or ethanol in 2019, while only a small percentage went to human consumption. In addition, corn productivity comes with environmental costs, chiefly in the form of greenhouse gas (GHG) emissions and water pollution. In this article, we briefly discuss the steps needed to transform our current linear corn-soybean systems into circular subsystems for open-field production of corn and soybeans in the U.S. Midwest.

In this work, we report experimental studies on the disinfection of irrigation water using a flow cell assembled with low-cost graphite plates as both anode and cathode. Natural irrigation waters collected from two irrigation locations (Reservoir 225 and Bott Well Pond) in Hawaii were used, and synthetic irrigation waters were prepared based on the chemical analysis of natural irrigation waters. The concentration of chloride was 10.2 mg/L in the synthetic Reservoir 225 water and 6.9 mg/L in the synthetic Bott Well pond water.Escherichia coliK12 ER2738 was selected as a model bacterium to evaluate the disinfection capability of the flow cell. Experiments performed in the synthetic irrigation waters showed thatE. coliwas inactivated by free chlorine species electro-generated from oxidation of chloride ions at the graphite anode. Complete removal ofE. coliwas achieved within 10 min in the synthetic irrigation waters. The disinfection of the natural irrigation waters took about four times longer than the disinfection of the synthetic irrigation waters. This result is most likely due to the presence of organic matter (and possibly other oxidizable species) in the natural irrigation waters. Practitioner points Electrochemical flow cell disinfects to 99.9% with commercial graphite electrodes. E. coliis removed in 10 min from synthetic irrigation water by a flow cell. E. coliremoval takes 4x longer in natural irrigation water. A minimum current density of >= 1 mA/cm(2)is required for disinfection. The primary disinfection mechanism is through chlorine generated from chloride ions.

Food systems are increasingly challenged to meet growing demand for specialty crops due to the effects of climate change and increased competition for resources. We apply a novel integrated methodology that includes climate, crop, economic, and life cycle assessment (LCA) models to US potato and tomato supply chains. We assess the effectiveness of changing management strategies to address climate change and the opportunity to relocate away from regions with increased water scarcity. We find that supply chains for two popular processed products in the United States, French fries and pasta sauce, will be remarkably resilient, through planting adaptation strategies that avoid higher temperatures. Land and water footprints will decline over time due to higher yields, and GHG emissions can be mitigated by waste reduction and process modification. Our integrated methodology can be applied to other crops and geographies, and the results could inform decision-making at multiple steps along supply chains.

AbstractThe ocean is the ultimate sink for anthropogenic pollution. According to the HydroSHED model, over 80% of the land mass on Earth is in a watershed that drains directly to the ocean (Lehner and Grill 2013). Until recently, the ocean seemed to be endlessly able to absorb all the waste that human activity has discharged into it. The Ocean Health Index (OHI) scores the health of the ocean on a range of criteria, from how clean the water is to the ability of the ocean to continue providing services such as food provision, carbon storage, tourism and recreation, and biodiversity (Halpern et al. 2012). The 2019 combined global ocean score was 71 out of 100 (as it has been for the last five years), showing that significant impairment has occurred, but that many of the functions and services of the ocean remain and must be better managed (OHI 2019). The Clean Water section of the OHI includes details on the statuses and pressures of chemical, nutrient, pathogen and trash pollution. It also includes social pressure as a further pressure. Indicators of resilience were based upon the Convention on Biological Diversity (in particular for marine ecosystems) and quality of governance (using Worldwide Governance Indicators). The score for Clean Water has tracked closely to the overall score, remaining at 70 for the past five years (OHI 2019). With an estimated 91% of all temperate and tropical coasts predicted to be heavily developed by 2050 (Nellemann et al. 2008), this is a critical time to significantly reduce and prevent anthropogenic pollution to the ocean.

This study discusses the environmental life cycle impacts of potato and tomato supply chains in a “cradle-to-grave” perspective. The principal focus is to evaluate the processed products, while fresh products are also briefly discussed. Processed products included are potato-chips, frozen fries and dehydrated flakes, and tomato-pasta sauce. The functional unit (FU) is 1 kg product(s), eaten at the consumer stage. Life cycle assessment (LCA) modeling has utilized multiple mechanistic crop models to estimate the crop yields, crop nutrient uptakes and irrigation water requirements. The farming systems represent the primary crop reporting districts where the selected crops are produced on a commercial scale in the United States. The post-harvest system was constructed utilizing the data collected from a processing plant and from other available studies. LCA modeling also constituted handling of co-products (e.g. starch in potatoes) and biowaste. A wide range of environmental impact categories were selected for the evaluation, which showed environmental differences between fresh and processed products. For instance, global warming potential for potato-fresh, chips, fries and dehydrated was 0.97, 0.85, 1.21 and 0.65 kg CO2-eq/FU respectively. For fresh tomato and tomato sauce, it was 0.74 and 1.5 kg CO2-eq/FU respectively. Likewise, fossil resource scarcity for fresh potatoes was higher than chips and dehydrated flakes, but lower than fries. Water consumption was slightly higher in fresh potatoes compared to the processed products. Similar impact patterns were found in fresh and processed tomato products. For most of the impact categories, processing and the agriculture systems were the major contributors. The contribution from the consumer stage varied with the ways the product is prepared, e.g. whether fries are oven heated or deep-fried in oil. Environmental mitigation measures include, the use of drip irrigation (for potatoes), and reducing: food miles, food waste and the use of secondary packaging materials.