Champaign County Research Articles

A flexible and efficient knowledge-guided machine learning data assimilation (KGML-DA) framework for agroecosystem prediction in the US Midwest

Process-based models are widely used to predict the agroecosystem dynamics, but such modeled results often contain considerable uncertainty due to the imperfect model structure, biased model parameters, and inaccurate or inaccessible model inputs. Data assimilation (DA) techniques are widely adopted to reduce prediction uncertainty by calibrating model parameters or dynamically updating the model state variables using observations. However, high computational cost, difficulties in mitigating model structural error, and low flexibility in framework development hinder its applications in large-scale agroecosystem predictions. In this study, we addressed these challenges by proposing a novel DA framework that integrates a Knowledge-Guided Machine Learning (KGML)-based surrogate with tensorized ensemble Kalman filter (EnKF) and parallelized particle swarm optimization (PSO) to effectively assimilate historical and in-season multi-source remote sensing data. Specifically, we incorporate knowledge from a process-based model, ecosys, into a Gated Recurrent Unit (GRU)-based hierarchical neural network. The hierarchical architecture of KGML-DA mimics key processes of ecosys and builds a causal relationship between target variables. Using carbon budget quantification in the US Corn-Belt as a context, we evaluated KGML-DA's performance in predicting key processes of the carbon cycle at three agricultural sites (US-Ne1, US-Ne2, US-Ne3), along with county-level (627 counties) and 30-m pixel-level (Champaign County, IL) grain yield. The site experiments show that updating the upstream variable, e.g., gross primary production (GPP), improved the prediction of downstream variables such as ecosystem respiration, net ecosystem exchange, biomass, and leaf area index (LAI), with RMSE reductions ranging from 9.2% to 30.5% for corn and 4.8% to 24.6% for soybean. Uncertainty in downstream variables was automatically constrained after correcting the upstream variables, demonstrating the effectiveness of the causality linkages in the hierarchical surrogate. We found joint use of in-season GPP and evapotranspiration (ET) products along with historical GPP and surveyed yields achieved the best prediction for county-level yields, while assimilating in-season LAI observations benefitted the prediction in extreme years. Uncertainty and error analysis of regional yield estimation demonstrated that KGML-DA could reduce prediction error by 26.5% for corn and 36.2% for soybean. Remarkably, the GPU-based tensor operation design makes this DA framework more than 7000 times faster than the PB model with a High-Performance Computing system, indicating the high potential of the proposed framework for in-season, high-resolution agroecosystem predictions.

Norflurazon and metribuzin as components of postemergence tank mixtures with HPPD-inhibiting herbicides for multiple-resistant waterhemp control

Field and greenhouse studies investigated the phytoene desaturase (PDS) and photosystem II (PSII)-inhibiting herbicides, norflurazon and metribuzin, as components of two- and three-way postemergence (POST) tank mixtures for controlling multiple herbicide-resistant (MHR) waterhemp (Amaranthus tuberculatus). Studies were conducted at two locations (Champaign County, Illinois, U.S.A (CHR) and McLean County, Illinois, U.S.A. (MCR)) during 2019 and 2020. One of three commercial HPPD-inhibiting herbicides (mesotrione, tembotrione or topramezone) was added to a tank mixture with norflurazon, a reduced rate of metribuzin, or both to determine if greater MHR waterhemp control with tank mixtures could be achieved compared to individual herbicides and assess the potential benefit of norflurazon. Field results indicated the addition of norflurazon to HPPD-inhibiting herbicides resulted in greater waterhemp control (14% increase on average) compared to individual herbicides applied alone. Additionally, metribuzin in combination with HPPD-inhibiting herbicides consistently increased control of MHR waterhemp populations compared to the herbicides applied alone. However, only the three-way tank mixture containing tembotrione at the MCR site reduced biomass relative to two-way treatments containing tembotrione, metribuzin or norflurazon. Greenhouse experiments characterized mixtures of norflurazon with metribuzin and the HPPD-inhibiting herbicides, mesotrione and topramezone. Waterhemp biomass was significantly reduced when metribuzin and HPPD inhibitors were combined in comparison to individual components. Two-way tank mixtures containing norflurazon with mesotrione or metribuzin also resulted in significant biomass reductions compared to herbicides applied alone in MHR waterhemp. However, lower control levels were noted in MHR waterhemp when norflurazon was mixed with either topramezone or topramezone plus metribuzin compared to topramezone alone. In summary, norflurazon and metribuzin can be effective tank mixture components with HPPD-inhibiting herbicides for MHR waterhemp control. However, more research on these tank mixtures is warranted to optimize weed control and crop selectivity, which includes investigating active ingredient ratios, application timings and droplet spectrum effects on coverage.

Heterocypris incongruens maintains an egg bank in stormwater habitats and influences the development of larval mosquito, Culex restuans.

Dormant propagules can provide a rapid colonization source for temporary aquatic habitats and set the trajectory for community dynamics, yet the egg banks of stormwater management systems have received little attention. We asked which species hatched from the sediment of drainage ditches in Champaign County, IL, and found bdelloid rotifers and ostracods (Heterocypris incongruens) to be the most common taxa. These sites also are colonized by mosquitoes, and we established laboratory experiments to examine interspecific interactions between common co-occurring taxa. Culex restuans larvae were reared in the presence or absence of H. incongruens at two intra- and interspecific densities (20 or 40 total individuals) and their survivorship to adulthood, development time to adulthood, adult body size, and sex ratio were determined. Survival for Cx. restuans was significantly lower at high larval density than at low larval density in both treatments. Culex restuans larvae reared in the presence of H. incongruens had a shorter development time to adulthood and emerged as larger adults compared to those reared in the absence of H. incongruens. The sex ratios in the H. incongruens treatments were female-biased whereas those in the Culex-only treatments were male-biased. These differences may have epidemiological implications, as only female mosquitoes serve as disease vectors. Our results emphasize the importance of understanding interspecific interactions in influencing larval mosquito development traits.

Fishes of Champaign County, Illinois: as affected by 120 years of stream changes

With data spanning over 120 years, the Fishes of Champaign County is a comprehensive, long-term investigation into the changing fish communities of east-central Illinois. Surveys first occurred in Champaign County in the late 1880s (40 sites), with subsequent surveys in 1928–1929 (125 sites), 1959–1960 (143 sites), and 1987–1988 (141 sites). Between 2012 and 2015, we resampled 122 sites across Champaign County. The combined data from these five surveys have produced a unique perspective into not only the fish communities of the region, but also insight into in-stream habitat changes during the past 120 years. After a period of degradation, fish communities appear to be improving throughout the county, demonstrated by the return of two state-threatened species that had not been recorded since 1928. Our analysis of in-stream habitat indicates a general trend away from small streams of various substrate types toward wider, deeper streams with a more uniform substrate. Fish community data support the results, indicating a shift from typical headwater species to those species that frequent deeper streams with more stable flows. Long-term surveys such as this are rare, and the data and analyses of these surveys can provide managers with valuable information to further restoration efforts using a historical perspective.

Mitigation of SARS-CoV-2 transmission at a large public university

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

The Effect of Work Requirements on Mental Health of Subsidized Housing Recipients: Evidence from the Housing Authority of Champaign County, Illinois

This study examines the early effect of work requirements on mental health of subsidized housing recipients. The Housing Authority of Champaign County (HACC) enforced work requirements for working-aged and non-disabled recipients and supported their transition to work with case management services. In addition, non-compliance with work requirements might result in the loss of housing subsidy. We collected survey data 1 year prior to and 1 year following the implementation of HACC’s work requirements to compare changes in mental health measures between work-able recipients who were and were not subject to work requirements. We calculate the average treatment effects on the treated estimates obtained from difference-in-differences with propensity score matching to control potential bias stemming from unobserved time-invariant variables and support the model’s parallel trend assumption. Our main results show that, during the early phase of work requirements, impacted heads of households were predicted to increase depression scores and decrease hopefulness scores relative to changes in mental health measures of the matched control groups over the same period. Recipients’ mental health would play a critical role in the success of HACC’s self-sufficiency strategies, and therefore the housing authority may strengthen the transition of hard-to-employ recipients into the workforce by offering careful assessment and screening to identify recipients with serious mental health problems or other employment barriers and reinforcing their access to supportive health and social services.

Control of waterhemp (Amaranthus tuberculatus) at multiple locations in Illinois with single preemergence applications of VLCFA-inhibiting herbicides

AbstractHerbicides that inhibit very-long-chain fatty acids (VLCFAs) have been widely used for preemergence control of annual monocot and small-seeded dicot weed species, such as waterhemp, since their discovery in the 1950s. VLCFA-inhibiting herbicides are often applied in combination with active ingredients that possess residual activity on small-seeded broadleaf weeds, which can make their contribution to preemergence waterhemp control difficult to quantify. Bare-ground field experiments were designed to investigate the efficacy of eight VLCFA-inhibiting herbicides applied at their minimum and maximum labeled rates for control of Illinois waterhemp populations. Four different locations were selected, two of which contained previously characterized VLCFA inhibitor–resistant waterhemp populations in Champaign County (CHR) and McLean County (MCR). Two locations with VLCFA inhibitor–sensitive waterhemp populations included the University of Illinois South Farm in Urbana, IL, and the Orr Research Center in Perry, IL. Soils at the CHR, MCR, and Urbana locations contained greater than 3% organic matter, but less than 3% organic matter at Perry. Non-encapsulated acetochlor and alachlor controlled CHR and MCR waterhemp populations 28 d after treatment (DAT), whereas other VLCFA-inhibiting herbicides resulted in 61% and 76% control of the CHR and MCR populations, respectively. In contrast, all VLCFA-inhibiting herbicides resulted in 81% and 88% control of the Perry and Urbana waterhemp populations, respectively, 28 DAT. Waterhemp control decreased by 42 DAT, especially for the VLCFA inhibitor–resistant CHR and MCR populations. Overall, VLCFA-inhibiting herbicides remain effective for controlling sensitive waterhemp, but most are not effective for controlling VLCFA inhibitor–resistant waterhemp populations. Proper herbicide stewardship and integrated weed management practices should be implemented to maintain VLCFA-inhibiting herbicide efficacy for waterhemp management in the future.

Characterization and inheritance of dicamba resistance in a multiple-resistant waterhemp (Amaranthus tuberculatus) population from Illinois

AbstractWaterhemp [Amaranthus tuberculatus (Moq.) Sauer] is one of the most troublesome agronomic weeds in the midwestern United States. The rapid evolution and selection of herbicide-resistance traits in A. tuberculatus is a major challenge in managing this species. An A. tuberculatus population, designated CHR, was identified in 2012 in Champaign County, IL, and previously characterized as resistant to herbicides from six site-of-action groups: 2,4-D (Group 4), acetolactate synthase inhibitors (Group 2), protoporphyrinogen oxidase inhibitors (Group 14), 4-hydroxyphenylpyruvate dioxygenase inhibitors (Group 27), photosystem II inhibitors (Group 5), and very-long-chain fatty-acid synthesis inhibitors (Group 15). Recently, ineffective control of CHR was observed in the field after dicamba application. Therefore, this research was initiated to confirm dicamba resistance, quantify the resistance level, and investigate its inheritance in CHR. Multiple field trials were conducted at the CHR location to confirm poor control with dicamba and compare dicamba treatments with other herbicides. Greenhouse trials were conducted to quantify the resistance level in CHR and confirm genetic inheritance of the resistance. In field trials, dicamba did not provide more than 65% control, while glyphosate and glufosinate provided at least 90% control. Multiple accessions were generated from controlled crosses and evaluated in greenhouse trials. Greenhouse dicamba dose–response experiments indicated a resistance level of 5- to 10-fold relative to a sensitive parental line. Dose–response experiments using F1 lines indicated that dicamba resistance was an incompletely dominant trait. Segregation analysis with F2 and backcross populations indicated that dicamba resistance had moderate heritability and was potentially a multigenic trait. Although dicamba resistance was predominantly inherited as a nuclear trait, minor maternal inheritance was not completely ruled out. To our knowledge, CHR is one of the first cases of dicamba resistance in A. tuberculatus. Further studies will focus on elucidating the genes involved in dicamba resistance.

Issue Information

Jackson County, Illinois, U.S.A., Photo by Nathan Soley (right) Champaign County, Illinois, U.S.A., Photo by Nathan Soley (left) Soley and Sipes “Reproductive biology and pollinators of the invasive shrub Autumn olive (Elaeagnus umbellata Thunberg)”. https://doi.org/10.1111/1442-1984.12307image

Spatiotemporal Derivation of Intermittent Ponding in a Maize–Soybean Landscape from Planet Labs CubeSat Images

Climate change is increasing the frequency and intensity of heavy precipitation in the US Midwest, overwhelming existing tile drainage, and resulting in temporary soil ponding across the landscape. However, lack of direct observations of the dynamics of temporal soil ponding limits our understanding of its impacts on crop growth and biogeochemical cycling. Satellite remote sensing offers a unique opportunity to observe and analyze this dynamic phenomenon at the landscape scale. Here we analyzed a series of red–green–blue (RGB) and near infrared (NIR) remote sensing images from the Planet Labs CubeSat constellation following a period of heavy precipitation in May 2017 to determine the spatiotemporal characteristics of ponding events in the maize–soybean cropland of Champaign County, Illinois USA. We trained Random Forest algorithms for near-daily images to create binary classifications of surface water versus none, which achieved kappa values around 0.9. We then analyzed the morphology of classification results for connected pixels across space and time and found that 2.5% (5180 ha) of this cropland was classified as water surface at some point during this period. The frequency distribution of areal ponding extent exhibited a log–log relationship; the mean and median areas of ponds were 1231 m2 and 126 m2, respectively, with 26.1% of identified ponds being at the minimum threshold area of 45 m2, and 2.5% of the ponds having an area greater than 104 m2 (1 ha). Ponds lasted for a mean duration of 2.4 ± 1.7 days, and 2.3% of ponds lasted for more than a week. Our results suggest that transient ponding may be significant at the landscape scale and ought to be considered in assessments of crop risk, soil and water conservation, biogeochemistry, and sustainability.

Visceral non-presence

The local slaughterhouse’s coronavirus cluster was the first large outbreak we heard about in Champaign County. The sprawling pork processing plant sits in the midst of cornfields some 17 miles north of the University of Illinois at Urbana-Champaign. Until early May, workers there processed 35 million pounds of pork a month. The company reported its first case on 25 April. Health inspectors arrived two days later to find the plant 90 percent out of compliance in its infection control practices. By 15 May, after testing 200 of the 627 workers for COVID-19, 83 got positive results. Management admitted it was ‘complex’ to track employees being tested and to follow up with those who had to be quarantined. That’s when they contacted the University of Illinois at Urbana-Champaign. They then announced confidently to the local press: We’ve got it under control. We have the scientists now.

0379 Green Space Exposure and Sleep Duration Among Supplemental Nutrition Assistance Program Participants

Abstract Introduction Emerging empirical evidence suggests green space exposure is protective against insufficient sleep. Limited studies exist, however, exploring the relationship between greenspace exposure and sleep among low income populations in the United States. Methods Using a sample of Supplemental Nutrition Assistance Program (SNAP) participants (n=104) recruited from Champaign County, Illinois, we examined the relationship between self-reported sleep duration and exposure to green space. Sleep duration was determined using the question, “On average, how many hours did you sleep each night during the past 4 weeks?” Green space exposure was determined using satellite imagery from the National Aeronautic Space Administration (NASA) normalized difference vegetation index (NDVI). An NDVI score was assigned to each participant based on residential geo-referenced data. Multiple linear regression was performed in SPSS to explore the relationship between self-reported sleep duration and green space. Results Higher number of hours of sleep within a 24-hour period was positively associated with higher scores for greenspace exposure (β=0.091, P=0.02), controlling for age, gender, smoking status, education, alcohol consumption, and sleep quality. Sleep duration was negatively associated with age (β=-0.03, P=0.007), but positively associated with sleep quality (β=0.856, P=0.008). Conclusion In a sample of SNAP participants, exposure to green space was associated with more hours of sleep per night. Additional studies with larger, and more geographically diverse samples of low income adults are needed to determine whether this relationship is robust. Support USDA UNC/DUKE BECR Center

River, Reaper, Rail: Agriculture and Identity in Ohio's Mad River Valley, 1795–1885 by Timothy H. H. Thoresen

Reviewed by: River, Reaper, Rail: Agriculture and Identity in Ohio's Mad River Valley, 1795–1885 by Timothy H. H. Thoresen Ginette Aley (bio) Keywords Ohio, Old Northwest, agriculture, farming, railroads, markets River, Reaper, Rail: Agriculture and Identity in Ohio's Mad River Valley, 1795–1885. By Timothy H. H. Thoresen. (Akron, OH: The University of Akron Press, 2018. Pp. 279. Paper, $59.95.) As late as 1860, the eve of the Civil War, Ohioans' collective identity was wrapped up in agriculture. As historian Timothy H. H. Thoresen observes, "Land to own and to farm, that was the desire" (114). Indeed, this sentiment pervaded the nineteenth-century Midwest. Although his study, River, Reaper, Rail: Agriculture and Identity in Ohio's Mad River Valley, 1795–1885, is firmly rooted in Champaign County, Ohio, its tracing of farmers' early market orientation, including adaptations of traditional farming practices to changing circumstances and technology, and development of state-sponsored farmer organizations tells a much broader story of agrarianism across the North and, specifically, emerging Midwest. Making liberal use of land, tax, and county records as well as census data, land policy, annual state agriculture reports, and newspapers, Thoresen deftly re-creates the world of nineteenth-century farming in Ohio, from the primitive pioneering phase to a post-Civil War era dominated by railroads. While his heavy reliance on local newspapers casts an impressionistic view on his interpretation, it nevertheless offers up some of the prominent male voices, concerns, and ideas in these farm communities. As others have done, Thoresen characterizes farmers as fundamentally conservative. Yet his study demonstrates at least an interest on their part in change and improvement—so long as the cost did not significantly alter or constrain farm operations. As shown here, farmers historically have also been innovators. [End Page 176] In 1805, two years after Ohio's statehood, Champaign County was established in the Mad River Valley in the west-central part of the state; however, settler-farmers had been pushing into the area from the east and by way of the Ohio River since the 1790s, especially after the 1795 Treaty of Greenville. New arrivals, who settled mainly along the waterways as well as the Virginia Military District, faced a physically arduous process in clearing the forested land, which typically required 3 to 5 years until farms were self-sustaining. The landscape became dotted with unfenced cattle and pigs; small grain cultivation; draft animals, especially oxen; and plowing at the rate of about an acre per day. Migrants came in several waves including after the War of 1812 and then again in the 1820s and 1830s, each time indicating land-purchase patterns that reflected changing land policies. In ways that call to mind the insightful work of noted agricultural and rural historian R. Douglas Hurt, Thoresen pays close attention to the farming practices and market attitudes settler-farmers brought with them and how both evolved with the new farming environment, transportation connections, and expanding market economy. Two key adaptations that advanced American agriculture and productivity were improved plows and the cradle scythe. Extremely marginal transportation and market access, however, loomed as the early nineteenth century's defining problems; solving them, the author points out, "is essentially the history of Champaign County" (11). One need only look at the legislative history concerning local and state-level agriculture societies and infrastructure-building—roads, bridges, canals, and early railroads—to discern growing market interest, locally, statewide, and regionally. Thoresen perceptively surmises that "participation in the market economy was not a conceptual problem; it was a practical problem" (39). Eliminating obstacles opened the door for and, as he characterizes, gave incentive to, farmers to strive for greater productivity, improved breeding of livestock, and higher-yielding seed. Clearly, though, the impact of the railroad on Champaign County, Ohio, farmers and American agriculture more broadly, even in its infancy in the 1850s, cannot be overstated. The prospects of commercial agriculture transformed ideas about farming. More market connections, reduction of transit time and freight charges not only made increased productivity logical but also led to a related rise in storage and processing enterprises such as grain-storage warehouses, grain cars, and so on. Greater productivity came...

A New Record Mayfly Ephemerella subvaria McDunnough (Ephemeroptera, Ephemerellidae) from Ohio, USA

In the spring of 2019, a new state record for a mayfly (Ephemeroptera) was collected at Cedar Run and the Mad River in Champaign County, Ohio, United States. Ephemerella subvaria McDunnough, 1931, was collected and identified as nymphs and subsequently reared to adults. This Ohio location is exceptional. The geographic distribution of the species is widespread in the eastern United States; however, its distribution in the upper midwest is limited to northern Michigan and northern Wisconsin, but is absent from the southern counties of those states, and from Illinois. It is rare in Indiana and northern Kentucky. Until this report it was unknown from Ohio. Nymphs were collected on 26 March 2019. Reared in a temperature-controlled aquarium, the subimago emerged on 27 April 2019 and the imago emerged on 30 April 2019. It is hypothesized that Cedar Bog Nature Preserve, Cedar Run, and the Mad River—remnants of streams in a prior swamp in western-central Ohio—provide a refugia for this out-of-place species.

Predation differentially structures immature mosquito populations in stormwater ponds

1. Understanding the factors underlying the abundance and distribution of species requires the consideration of a complex suite of interacting biotic and abiotic factors operating on multiple spatial and temporal scales. Larval mosquitoes inhabiting small human‐constructed ponds represent a unique opportunity to investigate the relative importance of these structuring mechanisms while simultaneously generating applied knowledge on mosquito control.2. A multi‐year field survey of 32 stormwater ponds was conducted in central Illinois (Champaign County). From each pond, data were collected on pond structure type and hydroperiod, the presence/absence of cattails (Typha spp.), and measures of total nitrogen, phosphorus, and organic carbon, and chlorophyll a. The communities of crustacean zooplankton and aquatic insects were characterised, and these taxa were assigned into two main groups: predators and competitors of larval mosquitoes. Structural equation modelling was used to explore the direct and indirect effects of these biotic and abiotic factors on larval density for three species of culicine mosquitoes (Culex pipiens, Culex restuans, and Aedes vexans).3. Hydroperiod had an indirect negative effect on C. pipiens density. However, this effect was mediated by predator density; more permanent ponds had more predators, which therefore reduced the density of C. pipiens larvae. Aedes vexans density was positively correlated with predator density. No predictor variables were found that explained variation in C. restuans density.4. This study show that the relative importance of these biotic and abiotic factors varies among species of culicine mosquitoes inhabiting stormwater ponds.

Characterization of multiple herbicide–resistant waterhemp (Amaranthus tuberculatus) populations from Illinois to VLCFA-inhibiting herbicides

AbstractField experiments were conducted in 2016 and 2017 in Champaign County, IL, to study a waterhemp [Amaranthus tuberculatus(Moq.) J. D. Sauer] population (CHR) resistant to 2,4-D and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-, photosystem II–, acetolactate synthase (ALS)-, and protoporphyrinogen oxidase–inhibiting herbicides. Two field experiments were designed to investigate the efficacy of very-long-chain fatty-acid (VLCFA)-inhibiting herbicides, including a comparison of active ingredients at labeled use rates and a rate titration experiment.Amaranthus tuberculatusdensity and control were evaluated at 28 and 42 d after treatment (DAT). Nonencapsulated acetochlor, alachlor, and pyroxasulfone provided the greatest PRE control of CHR (56% to 75%) at 28 DAT, while metolachlor,S-metolachlor, dimethenamid-P, and encapsulated acetochlor provided less than 27% control. In the rate titration study, nonencapsulated acetochlor controlled CHR more than equivalent field use rates ofS-metolachlor. Subsequent dose–response experiments with acetochlor,S-metolachlor, dimethenamid-P, and pyroxasulfone in the greenhouse included three multiple herbicide–resistant (MHR)A. tuberculatuspopulations: CHR-M6 (progeny generated from CHR), MCR-NH40 (progeny generated from Mclean County, IL), and ACR (Adams County, IL), in comparison with a sensitive population (WUS). Both CHR-M6 and MCR-NH40 are MHR to atrazine and HPPD, and ALS inhibitors and demonstrated higher survival rates (LD50) toS-metolachlor, acetochlor, dimethenamid-P, or pyroxasulfone than ACR (atrazine resistant but HPPD-inhibitor sensitive) and WUS. Based on biomass reduction (GR50), resistant to sensitive (R:S) ratios between CHR-M6 and WUS were 7.5, 6.1, 5.5, and 2.9 forS-metolachlor, acetochlor, dimethenamid-P, and pyroxasulfone, respectively. Values were greater for MCR-NH40 than CHR-M6, and ACR was the most sensitive to all VLCFA inhibitors tested. Complete control of all populations was achieved at or below a field use rate of acetochlor. In summary, field studies demonstrated CHR is not controlled by several VLCFA-inhibiting herbicides. Greenhouse dose–response experiments corroborated field results and generated R:S ratios (LD50) ranging from 4.5 to 64 for CHR-M6 and MCR-NH40 among the four VLCFA-inhibiting herbicides evaluated.

The Maya Classroom in Diaspora: Blending Community-Based Research and Advocacy in Champaign County, Illinois

Over the past ten years, professors and students from the University of Illinois have collaborated with the rapidly growing population of Maya residents in Champaign County, Illinois to develop opportunities to use, preserve, and pass on their linguistic and cultural skills

Microtopographic differences in soil properties and microbial community composition at the field scale

Soil biogeochemical processes, such as soil-atmosphere greenhouse gas (GHG) fluxes, are highly variable in space and time, even in homogenously managed agricultural fields. Although soil properties which regulate biogeochemical processes are known to vary predictably with topographic position at the hillslope to watershed scale in landscapes with noticeable topographic relief, the role of microtopography in influencing field scale spatial variability in soil properties in relatively flat landscapes, such as the Midwest U.S., is poorly understood. Moreover, microtopographic effects on soil microbial community composition and its functional importance in mediating biogeochemical processes have previously received little attention. We, therefore, investigated the effect of microtopography on soil properties and microbial community composition which may regulate soil biogeochemical process rates. We sampled paired poorly-drained depressional and well-drained upslope areas in eight replicate maize fields in Champaign County, Illinois. We observed microtopographic differences in soil pH, HCl-extractable Fe(III) concentrations, and soil organic C concentrations (P < 0.05). After normalizing for site variance, we also observed microtopographic differences in microbial community composition based on bacterial 16S rRNA, fungal ITS2, and nitrogen-cycling functional genes (archaeal and bacterial amoA, nirK, nirS, and Clade I nosZ), with soil pH and HCl-extractable Fe(III) exhibiting strong correlations with community structure (P < 0.05). Taxa capable of anaerobic metabolisms, such as Geobacter and Anaeromyxobacter, were relatively more abundant in poorly-drained, depressional soils (P < 0.05), suggesting a possible functional difference in the distinct communities. Overall, our findings demonstrate microtopographic differences in soil physicochemical properties and microbial community composition which could contribute to spatial variation in biogeochemical process rates.

Achieving Economic Self-Sufficiency Through Housing Assistance: An Assessment of a Self-Sufficiency Program of the Housing Authority of Champaign County, Illinois

ABSTRACTThis study examines the early impact of a Local Self-Sufficiency (LSS) program of the Housing Authority of Champaign County (HACC), Illinois, on recipients’ total annual household income and earnings, and employment. In 2013, HACC, through LSS, mandated work requirements for households with working-age, able-bodied adult members and imposed sanctions on those who did not meet the program requirements. We find that, between 2012 and 2014, the LSS program led to an average increase of $2,283 in earnings for an individual household. In aggregate, this allowed HACC to serve an additional 98 (9%) LSS-eligible households for a year. Also, LSS-eligible households experienced an increase in the employment–adult ratio by 11.6 percentage points. The LSS program also had a larger impact for more economically disadvantaged households with no prior work history.

STAIR: A generic and fully-automated method to fuse multiple sources of optical satellite data to generate a high-resolution, daily and cloud-/gap-free surface reflectance product

Surface reflectance data with high resolutions in both space and time have been desired and demanded by scientific research and societal applications. Standard satellite missions could not provide such data at both high resolutions. Fusion approaches that leverage the complementary strengths in various satellite sources (e.g. MODIS/VIIRS/GOES-R's sub-daily revisiting frequency and Landsat/Sentinel-2's high spatial resolution) provide a viable means to simultaneously achieve both high resolutions in the fusion data. In this paper, we presented a novel, generic and fully-automated method, STAIR, for fusing multi-spectral satellite data to generate a high-frequency, high-resolution and cloud-/gap-free data. Building on the time series of multiple sources of satellite data, STAIR first imputes the missing-value pixels (due to cloud cover or sensor mechanical issues) in satellite images using an adaptive-average correction process, which takes into account different land covers and neighborhood information of miss-value pixels through an automatic segmentation. To fuse satellite images, it employs a local interpolation model to capture the most informative spatial information provided by the high spatial resolution data (e.g., Landsat) and then performs an adjustment step to incorporate the temporal patterns provided by the high-frequency data (e.g., MODIS). The resulting fused products contain daily, high spatial resolution and cloud-/gap-free fused images. We tested our algorithm to fuse surface reflectance data of MODIS and Landsat in Champaign County at Illinois and generated daily time series for all the growing seasons (Apr 1 to Nov 1) from 2000 to 2015 at 30 m resolution. Extensive experiments demonstrated that STAIR not only captures correct texture patterns but also predicts accurate reflectance values in the generated images, with a significant performance improvement over the classic STARFM algorithm. This method is computationally efficient and ready to be scaled up to continental scales. It is also sufficiently generic to easily include various optical satellite data for fusion. We envision this novel algorithm can provide effective means to leverage historical optical satellite data to build long-term daily, 30 m surface reflectance record (e.g. from 2000 to present) at continental scales for various applications, as well as produce operational near-realtime daily and high-resolution data for future earth observation applications.