Comparative analysis of diets in Sioux Falls: Influence of sociodemographic characteristics, alignment to US national diet and healthy diet.

Continuous examination of diets and factors that influence dietary patterns is vital to improve diet quality. The objectives of this study are to evaluate the average diet of adults in the Sioux Falls Metropolitan Statistical Area (SFMSA), USA, examining sociodemographic differences in dietary intake and compare the average diet in the SFMSA (SF Diet) to the U.S. national average and USDA healthy dietary guidelines. A cross-sectional population-based study was conducted and 127 individuals were surveyed from August 2020 to August 2021. Dietary intake was assessed using the self-reported single 24-h dietary recall method and sociodemographic questions. Main effects and first order interactions of participant sociodemographic characteristics were considered. Main findings show that men had higher intake of meat, poultry, and eggs (p < 0.05) and alcohol, particularly older men (p < 0.05), than women. Higher alcohol intake was found for participants with lower levels of income and education (p < 0.01). The intake of fish and seafood was higher for older adults with a high level of income (p < 0.01). Differences were found between the SF diet and the national average but both followed a similar trend (e.g., low in fruits and vegetables and high in solid fats) and did not meet dietary guidelines, particularly for nutrient-dense foods. The intake of total vegetables (p < 0.001) and dark green vegetables (p < 0.001) was higher in the SF Diet and the national average was higher in total grains (p < 0.05), refined grains (p < 0.01), oils and fats (p < 0.001), solid fats (p < 0.001), and added sugar (p < 0.001). By not meeting the dietary guidelines, the findings of this study raise public health concerns.

Techno-economic and life cycle assessment of agrivoltaic system (AVS) designs.

Land use competition between agricultural activities and ground-mounted solar photovoltaic (PV) deployment has increased worldwide attention to hybrid agriculture, and PV systems known as agrivoltaic systems (AVS) in efforts to increase the efficiency of energy and food production and minimize the land use competition. However, little is known about AVS's economic feasibility and environmental tradeoffs. Here we aim to evaluate the techno-economic and environmental impacts of four AVS configurations (full density, half density, mono-axial tracking, and bi-axial tracking) and compare their performance against PV-only systems. We used the life cycle revenue generated from a hectare of land area ($/ha) as a functional unit of our analysis. We found that all AVS configurations outperformed PV-only systems in the economic feasibility assessment, where bi-axial tracking was the best-performing AVS. Further, we developed a case scenario for agricultural farmers to determine the minimum selling price of electricity required for AVS to compete with the economic performance of crop-only farms. We found that the AVS designs require additional incentives (2¢ - 6¢ per kWh of electricity generation) to be as competitive as the crop-only farms. The life cycle environmental assessment demonstrated that the AVS has better environmental performance than PV-only systems, with ∼15-55 % less environmental impacts per functional unit. On average, electricity generation accounts for ∼80 % of AVS environmental impacts, while food production and water demand account for ∼20 %. Additionally, a sensitivity analysis conducted on various uncertain parameters, such as crop yield, water demand, electricity selling price, crop selling prices, discount, and inflation rates, while varying these parameters across broader ranges, indicates that AVS designs become a more economically and environmentally sustainable alternative over PV-only systems in the majority (>66 %) of the data analyzed.

Systematic review on effects of bioenergy from edible versus inedible feedstocks on food security.

Achieving food security is a critical challenge of the Anthropocene that may conflict with environmental and societal goals such as increased energy access. The "fuel versus food" debate coupled with climate mitigation efforts has given rise to next-generation biofuels. Findings of this systematic review indicate just over half of the studies (56% of 224 publications) reported a negative impact of bioenergy production on food security. However, no relationship was found between bioenergy feedstocks that are edible versus inedible and food security (P value = 0.15). A strong relationship was found between bioenergy and type of food security parameter (P value < 0.001), sociodemographic index of study location (P value = 0.001), spatial scale (P value < 0.001), and temporal scale (P value = 0.017). Programs and policies focused on bioenergy and climate mitigation should monitor multiple food security parameters at various scales over the long term toward achieving diverse sustainability goals.

Site Preparation Drives Long-Term Plant Community Dynamics in Restored Tallgrass Prairie: A Case Study in Southeastern South Dakota.

Most tallgrass prairies have been destroyed or altered, making restoration an important component to their conservation. Our goal was to evaluate progress 12-years post-restoration at Spirit Mound Historic Prairie and determine whether the outcomes varied based on different land use and restoration histories across the site. We examined changes in plant diversity, richness, evenness, non-native species relative abundance, and community composition from 2004 to 2013. Areas with different restoration treatments and land-use histories showed divergent results. Seventy percent of the site, previously annual row crop, was reconstructed using herbicide application followed by native seeding (hereafter reconstruction). Areas that were previously grazed, 15 % of the site, were restored with only partial seeding and no herbicide treatment (hereafter rehabilitation). Species richness and diversity increased over 40 % in the reconstruction since 2004 and remained over 1.9 times higher in the reconstructed areas than rehabilitated areas. Diversity did not change in the rehabilitation, but richness increased 47 % since 2004. Evenness decreased 11-26 % over time in both areas. Non-native species relative abundance did not change from 2004 to 2013, and remained five times higher in the rehabilitation than the reconstruction. Native C4 grass and forb abundance increased over time in the reconstruction, whereas non-native C3 grasses remained dominant in the rehabilitation. These results showed that restoration outcomes were radically different 12-years post-restoration among areas with different prior land uses that were subjected to different restoration practices. Long-term assessments are important to accurately determine restoration progress and inform management decisions.

How efficiently do corn- and soybean-based cropping systems use water? A systems modeling analysis.

Agricultural systems are being challenged to decrease water use and increase production while climate becomes more variable and the world's population grows. Low water use efficiency is traditionally characterized by high water use relative to low grain production and usually occurs under dry conditions. However, when a cropping system fails to take advantage of available water during wet conditions, this is also an inefficiency and is often detrimental to the environment. Here, we provide a systems-level definition of water use efficiency (sWUE) that addresses both production and environmental quality goals through incorporating all major system water losses (evapotranspiration, drainage, and runoff). We extensively calibrated and tested the Agricultural Production Systems sIMulator (APSIM) using 6 years of continuous crop and soil measurements in corn- and soybean-based cropping systems in central Iowa, USA. We then used the model to determine water use, loss, and grain production in each system and calculated sWUE in years that experienced drought, flood, or historically average precipitation. Systems water use efficiency was found to be greatest during years with average precipitation. Simulation analysis using 28 years of historical precipitation data, plus the same dataset with ± 15% variation in daily precipitation, showed that in this region, 430 mm of seasonal (planting to harvesting) rainfall resulted in the optimum sWUE for corn, and 317 mm for soybean. Above these precipitation levels, the corn and soybean yields did not increase further, but the water loss from the system via runoff and drainage increased substantially, leading to a high likelihood of soil, nutrient, and pesticide movement from the field to waterways. As the Midwestern United States is predicted to experience more frequent drought and flood, inefficiency of cropping systems water use will also increase. This work provides a framework to concurrently evaluate production and environmental performance of cropping systems.

Subsurface Drainage Nitrate and Total Reactive Phosphorus Losses in Bioenergy-Based Prairies and Corn Systems.

We compare subsurface-drainage NO-N and total reactive phosphorus (TRP) concentrations and yields of select bioenergy cropping systems and their rotational phases. Cropping systems evaluated were grain-harvested corn-soybean rotations, grain- and stover-harvested continuous corn systems with and without a cover crop, and annually harvested reconstructed prairies with and without the addition of N fertilizer in an Iowa field. Drainage was monitored when soils were unfrozen during 2010 through 2013. The corn-soybean rotations without residue removal and continuous corn with residue removal produced similar mean annual flow-weighted NO-N concentrations, ranging from 6 to 18.5 mg N L during the 4-yr study. In contrast, continuous corn with residue removal and with a cover crop had significantly lower NO-N concentrations of 5.6 mg N L when mean annual flow-weighted values were averaged across the 4 yr. Prairies systems with or without N fertilization produced significantly lower concentrations below <1 mg NO-N L than all the row crop systems throughout the study. Mean annual flow-weighted TRP concentrations and annual yields were generally low, with values <0.04 mg TRP L and <0.14 kg TRP ha, and were not significantly affected by any cropping systems or their rotational phases. Bioenergy-based prairies with or without N fertilization and continuous corn with stover removal and a cover crop have the potential to supply bioenergy feedstocks while minimizing NO-N losses to drainage waters. However, subsurface drainage TRP concentrations and yields in bioenergy systems will need further evaluation in areas prone to higher levels of P losses.