Corn Belt States Research Articles

Relating carbon and nitrogen transport from constructed farm drainage

Fertility and crop production in soils of the recently-glaciated agricultural Midwestern U.S. link to soil inorganic and organic carbon, soil nitrogen and nitrogen inputs. Research relating transport of each to the others through the constructed drainage network to receiving streams is sparse. The main objective of this work was to quantify and characterize concentrations and yields of inorganic and organic carbon (IC and OC) along with nitrate-nitrogen (NO3-N) using a four-year dataset that included discharge from two managed drainage districts in the Cornbelt state of Iowa. Our analysis shows loss of carbon through these constructed drainage networks averages 124 kg ha−1 yr−1 with more than 90% of this total in carbonate form and only 7% in organic forms, a small amount relative to soil organic stores. Transport of NO3-N can total as much as 97 kg ha−1 yr−1. Although loads of IC, OC and NO3-N all vary similarly with discharge, NO3-N is especially transport-limited. Elevated OC concentrations in March are likely linked to recent manure application to soil surfaces, with concentrations returning to a consistent baseline thereafter. Concentrations of IC are lowest at high flows, indicating dilution by fresh water from recent hydrologic events into the drainage system which disproportionately mobilize NO3-N compared to IC. Although yields of IC and OC to the drainage system indicate tile drainage does not threaten to deplete soil organic matter stores, returning the system to a condition where carbon and nitrogen cycle together could improve stream water quality.

Provision of Climate Services for Agriculture: Public and Private Pathways to Farm Decision-Making

AbstractThe pathways between climate information producers and agricultural decision-makers are evolving and becoming more complex, with information increasingly flowing through both public and for-profit intermediaries and organizations. This study characterizes the various channels of climate information flow, as well as the needs and preferences of information intermediaries and end users. We use data from a 2016 survey of farmers and agricultural advisors in 12 U.S. Corn Belt states to evaluate perceptions of climate information and its usability. Our findings reinforce the view that much weather and climate information is not reaching farmers explicitly but also suggest that farmers may not be aware of the extent to which the information is packaged with seed, input, or management recommendations. For farmers who are using weather and climate information, private services such as subscription and free tools and applications (apps) are as influential as publicly provided services. On the other hand, we find that agricultural advisors are engaged users and transformers of both public and private sources of weather/climate information and that they choose sources of information based on qualities of salience and credibility. Our results suggest that climate information providers could improve the use of information in agriculture by engaging advisors and farmers as key stakeholders and by strategically employing multiple delivery pathways through the private and public sectors.

An Empirical Structural Model of Productivity and Conservation Reserve Program Participation

The Conservation Reserve Program (CRP), which provides incentives for landowners to idle erodible and marginal farmland, faced new challenges as record-high commodity prices significantly affected landowners' interests in the program in recent years. We develop and estimate an empirical structural model to examine the manner in which productivity, market conditions, and CRP payment affect landowners' land use decisions. The model carefully controls for the endogeneity of CRP payment and landowners' self-selection into the program. The parameter estimates are used to simulate how changes in agricultural prices and CRP payment influence program enrollment and cost across the Corn Belt states.

Soil as Social‐Ecological Feedback: Examining the “Ethic” of Soil Stewardship among Corn Belt Farmers

In this article we examine in‐depth interviews with farmers (n = 159) from nine Corn Belt states. Using a grounded theory approach, we identified a “soil stewardship ethic,” which exemplifies how farmers are talking about building the long‐term sustainability of their farm operation in light of more variable and extreme weather events. Findings suggest that farmers' shifting relationship with their soil resources may act as a kind of social‐ecological feedback that enables farmers to implement adaptive strategies (e.g., no‐till farming, cover crops) that build resilience in the face of increasingly variable and extreme weather, in contrast to emphasizing short‐term adjustments to production that may lead to greater vulnerability over time. The development of a soil stewardship ethic may help farmers to resolve the problem of an apparent trade‐off between short‐term productivist goals and long‐term conservation goals and in doing so may point toward an emergent aspect of a conservationist identity. Focusing on the message of managing soil health to mitigate weather‐related risks and preserving soil resources for future generations may provide a pragmatic solution for helping farmers to reorient farm production practices, which would have soil building and soil saving at their center.

The trouble with cover crops: Farmers’ experiences with overcoming barriers to adoption

AbstractCover crops are known to promote many aspects of soil and water quality, yet estimates find that in 2012 only 2.3% of the total agricultural lands in the Midwestern USA were using cover crops. Focus groups were conducted across the Corn Belt state of Iowa to better understand how farmers confront barriers to cover crop adoption in highly intensive agricultural production systems. Although much prior research has focused on analyzing factors that help predict cover crop use on farms, there is limited research on how farmers navigate and overcome field-level (e.g. proper planting of a cover crop) and structural barriers (e.g. market forces) associated with the use of cover crops. The results from the analysis of these conversations suggest that there is a complex dialectical relationship between farmers' individual management decisions and the broader agricultural context in the region that constrains their decisions. Farmers in these focus groups shared how they navigate complex management decisions within a generally homogenized agricultural and economic landscape that makes cover crop integration challenging. Many who joined the focus groups have found ways to overcome barriers and successfully integrate cover crops into their cropping systems. This is illustrated through farmers' descriptions of their ‘whole system’ approach to cover crops management, where they described how they prioritize the success of their cover crops by focusing on multiple aspects of management, including changes they have made to nutrient application and modifications to equipment. These producers also engage with farmer networks to gain strategies for overcoming management challenges associated with cover crops. Although many participants had successfully planted cover crops, they tended to believe that greater economic incentives and/or more diverse crop and livestock markets would be needed to spur more widespread adoption of the practice. Our results further illustrate how structural and field-level barriers constrain individual actions, as it is not simply the basic agronomic considerations (such as seeding and terminating cover crops) that pose a challenge to their use, but also the broader economic and market drivers that exist in agriculturally intensive systems. Our study provides evidence that reducing structural barriers to adoption may be necessary to increase the use of this conservation practice to reduce environmental impacts associated with intensive agricultural production.

Land management strategies for improving water quality in biomass production under changing climate

The Corn Belt states are the largest corn-production areas in the United States because of their fertile land and ideal climate. This attribute is particularly important as the region also plays a key role in the production of bioenergy feedstock. This study focuses on potential change in streamflow, sediment, nitrogen, and phosphorus due to climate change and land management practices in the South Fork Iowa River (SFIR) watershed, Iowa. The watershed is covered primarily with annual crops (corn and soybeans). With cropland conversion to switchgrass, stover harvest, and implementation of best management practices (BMPs) (such as establishing riparian buffers and applying cover crops), significant reductions in nutrients were observed in the SFIR watershed under historical climate and future climate scenarios. Under a historical climate scenario, suspended sediment (SS), total nitrogen (N), and phosphorus (P) at the outlet point of the SFIR watershed could decrease by up to 56.7%, 32.0%, and 16.5%, respectively, compared with current land use when a portion of the cropland is converted to switchgrass and a cover crop is in place. Climate change could cause increases of 9.7% in SS, 4.1% in N, and 7.2% in P compared to current land use. Under future climate scenarios, nutrients including SS, N, and P were reduced through land management and practices and BMPs by up to 54.0% (SS), 30.4% (N), and 7.1% (P). Water footprint analysis further revealed changes in green water that are highly dependent on land management scenarios. The study highlights the versatile approaches in landscape management that are available to address climate change adaptation and acknowledged the complex nature of different perspectives in water sustainability. Further study involving implementing landscape design and management by using long-term monitoring data from field to watershed is necessary to verify the findings and move toward watershed-specific regional programs for climate adaptation.

A spatiotemporal analysis of Midwest US temperature and precipitation trends during the growing season from 1980 to 2013

Since late 1970s, climate warming has been widely recognized. In the Midwest, farmers cannot rely on the normal calendar anymore, and it has become critically necessary to evaluate the most recent climate trends relative to growing season in order to conduct adaptation efforts for agriculture. Based on the homogenized historical monthly temperature and precipitation records during the period of 1980–2013 from 302 observing stations in the 12 Midwestern US states, we investigate the climate trends on four timescales: monthly, early growing season, late growing season, and the entire growing season. The climate metrics include maximum temperature, minimum temperature, average temperature, diurnal temperature range, and precipitation. Nonparametric Sen's Slope together with the nonparametric Mann–Kendall test is used to estimate the decadal trend and to detect the statistical significance. The results show that growing season average temperature has increased at a rate of 0.15 °C decade−1 over the Midwest United States. Within the growing season, minimum temperature is increasing faster in the early growing season, especially in June, while maximum temperature is increasing faster in the late growing season, especially in September. Spatially, statistically significant (p ≤ 0.05) growing season warming is more focused in the southern part of the region in the early growing season but in the northern part of the region in the late growing season. Over the Midwest, dominant trends in diurnal temperature range are decreasing during most months, with the exception of September. The majority of the locations show increasing trends in growing season precipitation, yet few are statistically significant. Furthermore, precipitation has been increasing in the early growing season but decreasing in the late growing season. This within-season reversing trend in precipitation is found in 8 of 12 Corn Belt states: Illinois, Iowa, Michigan, Minnesota, Missouri, Nebraska, North Dakota, and Wisconsin.

Modeled Impacts of Cover Crops and Vegetative Barriers on Corn Stover Availability and Soil Quality

Environmentally benign, economically viable, and socially acceptable agronomic strategies are needed to launch a sustainable lignocellulosic biofuel industry. Our objective was to demonstrate a landscape planning process that can ensure adequate supplies of corn (Zea mays L.) stover feedstock while protecting and improving soil quality. The Landscape Environmental Assessment Framework (LEAF) was used to develop land use strategies that were then scaled up for five U.S. Corn Belt states (Nebraska, Iowa, Illinois, Indiana, and Minnesota) to illustrate the impact that could be achieved. Our results show an annual sustainable stover supply of 194 million Mg without exceeding soil erosion T values or depleting soil organic carbon [i.e., soil conditioning index (SCI) > 0] when no-till, winter cover crop, and vegetative barriers were incorporated into the landscape. A second, more rigorous conservation target was set to enhance soil quality while sustainably harvesting stover. By requiring erosion to be <1/2 T and the SCI-organic matter (OM) subfactor to be > 0, the annual sustainable quantity of harvestable stover dropped to148 million Mg. Examining removal rates by state and soil resource showed that soil capability class and slope generally determined the effectiveness of the three conservation practices and the resulting sustainable harvest rate. This emphasizes that sustainable biomass harvest must be based on subfield management decisions to ensure soil resources are conserved or enhanced, while providing sufficient biomass feedstock to support the economic growth of bioenergy enterprises.

Nutrient Sufficiency Concepts for Modern Corn Hybrids: Impacts of Management Practices and Yield Levels

Over the last 70 years, national corn yield gains have occurred because of superior genetic yield potentials and management improvements such as improved water management, higher plant densities, and earlier planting dates. Some management recommendations, such as those from seed companies that promote optimum plant densities, are often environment, hybrid, and/or yield-range specific. Nitrogen rate recommendations for corn are updated annually in the Corn Belt states and are sometimes adjusted for regions or soil zones within a state. In contrast, nutrient guidelines for nutrients other than N are assumed to be constant per unit of yield produced, and have generally not been updated in key corn-producing states. Some recent studies providing nutrient content values for corn grain and/or stover did not account for management practices and yield levels for which nutrient replacement recommendations would be pertinent. The purpose of this report is to illustrate how macro- and micronutrient contents for modern corn hybrids can change in the context of diverse plant densities, N rates, and accompanying yield range influences in certain environments. The information presented here can be used to better understand nutrient content and removal for more precisely implementing best nutrient management practices for current corn hybrids at diverse yield ranges.

Understanding Corn Belt farmer perspectives on climate change to inform engagement strategies for adaptation and mitigation

Development of extension and outreach that effectively engage farmers in adaptation and/or mitigation activities can be informed by an improved understand- ing of farmers' perspectives on and related impacts. This research employed latent class analysis (LCA) to analyze data from a survey of 4,778 farmers from 11 US Corn Belt states. The research focused on two related research questions: (1) to what degree do farmers differ on key measures of beliefs about change, experience with extreme weather, perceived risks to agriculture, efficacy, and level of support for public and pri- vate adaptive and mitigative action; and (2) are there potential areas of common ground among farmers? Results indicate that farmers have highly heterogeneous perspectives, and six distinct classes of farmers are identified. We label these as the following: the concerned (14%), the uneasy (25%), the uncertain (25%), the unconcerned (13%), the confident (18%), and the detached (5%). These groups of farmers differ primarily in terms of beliefs about change, the degree to which they had experienced extreme weather, and risk per- ceptions. Despite substantial differences on these variables, areas of similarity were discerned on variables measuring farmers' (1) confidence that they will be able to deal with increases in and (2) support for public and private efforts to help farmers adapt to increased variability. These results can inform segmented approaches to outreach that target subpopulations of farmers as well as broader engagement strategies that would reach wider populations. Further, findings suggest that strategies with specific reference to might be most effective in engaging the subpopulations of farmers who believe that is occurring and a threat, but that use of less charged terms such as would likely be more effective with a broader range of farmers. Outreach efforts that (1) appeal to farmers' problem solving capacity and (2) employ terms such as weather variability instead of more charged terms such as climate change are more likely to be effective with a wider farmer audience.

Effects of Japanese Beetle (Coleoptera: Scarabaeidae) and Silk Clipping in Field Corn

Japanese beetle (Popillia japonica Newman) is an emerging silk-feeding insect found in fields in the lower Corn Belt and Midsouthern United States. Studies were conducted in 2010 and 2011 to evaluate how silk clipping in corn affects pollination and yield parameters. Manually clipping silks once daily had modest effects on yield parameters. Sustained clipping by either manually clipping silks three times per day or by caging Japanese beetles onto ears affected total kernel weight if it occurred during early silking (R1 growth stage). Manually clipping silks three times per day for the first 5 d of silking affected the number of kernels per ear, total kernel weight, and the weight of individual kernels. Caged beetles fed on silks and, depending on the number of beetles caged per ear, reduced the number of kernels per ear. Caging eight beetles per ear significantly reduced total kernel weight compared with noninfested ears. Drought stress before anthesis appeared to magnify the impact of silk clipping by Japanese beetles. There was evidence of some compensation for reduced pollination by increasing the size of pollinated kernels within the ear. Our results showed that it requires sustained silk clipping during the first week of silking to have substantial impacts on pollination and yield parameters, at least under good growing conditions. Some states recommend treating for Japanese beetle when three Japanese beetles per ear are found, silks are clipped to < 13 mm, and pollination is < 50% complete, and that recommendation appears to be adequate.

Effect of corn stover compositional variability on minimum ethanol selling price (MESP)

A techno-economic sensitivity analysis was performed using a National Renewable Energy Laboratory (NREL) 2011 biochemical conversion design model varying feedstock compositions. A total of 496 feedstock near infrared (NIR) compositions from 47 locations in eight US Corn Belt states were used as the inputs to calculate minimum ethanol selling price (MESP), ethanol yield (gallons per dry ton biomass feedstock), ethanol annual production, as well as total installed project cost for each composition. From this study, the calculated MESP is $2.20 ± 0.21 (average ± 3 SD) per gallon ethanol.

First‐Year Corn after Alfalfa Showed No Response to Fertilizer Nitrogen under No‐Tillage

Although fertilizer N response of first‐year corn (Zea mays L.) following alfalfa (Medicago sativa L.) has been reported for more than 350 site‐years of research, N responses under no‐tillage have been reported for only 17 site‐years. To determine the rate of N fertilizer required for first‐year corn after alfalfa in no‐tillage systems, on‐farm experiments were conducted at seven locations in southern Minnesota and southwestern Wisconsin. The accuracy of the presidedress soil nitrate test (PSNT) and basal stalk nitrate test (BSNT) to identify the need for supplemental N in first‐year, no‐tillage corn also was evaluated. Across seven site‐years, no yield response to fertilizer N was observed for corn grain, cob, stover, or silage yield, confirming that alfalfa N credits can supply the entire N requirement of no‐tillage corn following alfalfa. Critical levels of PSNT used in other U.S. Corn Belt states, incorrectly predicted responses to supplemental N at all six locations where PSNT was measured (soil NO3–N concentrations were ≤18 mg kg−1), suggesting that critical levels may need to be reduced in no‐tillage corn following alfalfa. In this first report under no‐tillage conditions, the BSNT concentrations in nonfertilized corn after alfalfa were in the marginal range at two locations (between 250 and 700 mg NO3–N kg−1) and optimum or above at the other five locations, indicating that the BSNT incorrectly characterized N supply in two of seven cases.

Simulated Local and Remote Biophysical Effects of Afforestation over the Southeast United States in Boreal Summer*

Abstract Afforestation has been proposed as a climate change mitigation strategy by sequestrating atmospheric carbon dioxide. With the goal of increasing carbon sequestration, a Congressional project has been planned to afforest about 18 million acres by 2020 in the Southeast United States (SEUS), the Great Lake states, and the Corn Belt states. However, biophysical feedbacks of afforestation have the potential to counter the beneficial climatic consequences of carbon sequestration. To assess the potential biophysical effects of afforestation over the SEUS, the authors designed a set of initial value ensemble experiments and long-term quasi-equilibrium experiments in a fully coupled Community Climate System Model, version 3.5 (CCSM3.5). Model results show that afforestation over the SEUS not only has a local cooling effect in boreal summer [June–August (JJA)] at short and long time scales but also induces remote warming over adjacent regions of the SEUS at long time scales. Precipitation, in response to afforestation, increases over the SEUS (local effect) and decreases over adjacent regions (remote effect) in JJA. The local surface cooling and increase in precipitation over SEUS in JJA are hydrologically driven by the changes in evapotranspiration and latent heat flux. The remote surface warming and decrease in precipitation over adjacent regions are adiabatically induced by anomalous subsidence. Our results suggest that the planned afforestation efforts should be developed carefully by taking account of short-term (local) and long-term (remote) biophysical effects of afforestation.

Farmland cash rents and the dollar

We explore whether the U.S. exchange rate could have an influence on cash rental rates for farmland in five U.S. cornbelt states. We find that farmland cash rents have a fairly strong, positive correlation with the U.S. dollar, in terms of its real value relative to major agricultural trading partners. One explanation for the correlation is that a strong dollar lowers the price of key inputs and thus has purchasing power effects. A strong dollar may therefore be associated with higher net returns, and the payment of higher cash rents by farmers. We find support for this hypothesis through a series of econometric models.

Tweak, Adapt, or Transform: Policy Scenarios in Response to Emerging Bioenergy Markets in the U.S. Corn Belt

Atwell, R. C., L. A. Schulte, and L. M. Westphal. 2011. Tweak, adapt, or transform: policy scenarios in response to emerging bioenergy markets in U.S. corn belt. Ecology and Society 16(1): 10. https://doi.org/10.5751/ES-03854-160110

Potential Environmental Impacts of Increased Reliance on Corn-Based Bioenergy

This paper integrates economic and physical models to assess: a) how increases in agricultural commodity prices, driven by ethanol production and other factors, affect land use and cropping systems in the US Midwest, and b) how the changes in land use and cropping systems in turn affect environmental quality in the region. The empirical framework includes a set of econometric models that predict land conversion, crop choices, and crop rotations at the parcel level based on commodity prices, land quality, climate conditions, and other physical characteristics at the sites. The predictions are then combined with site-specific environmental production functions to determine the effect of rising commodity prices on nitrate runoff and leaching, soil water and wind erosion, and carbon sequestration. Results suggest that increasing commodity prices will result in widespread conversions of non-cropland to cropland. Fifty percent of the region’s pasture and range land will be converted to cropland with $6 corn. Rising commodity prices will also result in dramatic changes in crop mix and rotation systems in the Midwest. With $6 corn, the total acreage of corn will increase by 23% and 40% in the Corn Belt and Lake States, respectively; the acreage of continuous corn will increase considerably in both regions as well. These changes in land use and crop mix will have a large impact on agricultural pollution. Approaches to mitigating the environmental impacts are discussed.

Expanding the US Cornbelt Biomass Portfolio: Forester Perceptions of the Potential for Woody Biomass

With the strong emergence of the bioeconomy in the US, there is growing interest in the ability of biomass production systems to meet the legislated demand for cellulosic biofuels. While corn grain will continue to comprise the primary feedstock for biofuel in the Cornbelt, it is unlikely that a single biomass feedstock will suit all the needs of an evolving bioenergy market; thus, the potential contribution of woody biomass should be considered. To meet informational needs, we conducted structured interviews with state-employed professional foresters along the Mississippi River corridor in five Corn Belt states (Illinois, Iowa, Minnesota, Missouri, and Wisconsin). Foresters were queried regarding the types of woody materials available, ecological considerations, the likely silvicultural systems that might support a biomass market, and their experiences with landowner management decisions as related to removing currently low-value material. Results suggest noteworthy interest in expanded woody biomass market systems within our study area. Furthermore, substantial opportunities exist to capture trimmings, small-diameter, and low-quality material in conjunction with on-going intermediate stand treatments or sawtimber harvests that are common in the region; capturing social and economic value while potentially contributing to long-term forest health. Costs for removing this material are estimated to range between $185–494/ha ($75–200/ac) depending on site conditions and accessibility. Such a wide range in costs (and therefore break-even biomass prices) suggests that some properties throughout the study region may be priced out of the market, at least in the initial stages of market development. Markets are distinctly lacking at present, however, and our interviewees suggested that market-pull will be required to organize a well-rounded infrastructure to harvest, process, store, and transport woody materials. This and future studies will be significant because they inform the enhancement of agricultural prosperity on small-to-medium farms and contribute to regional and national energy goals in ways that ideally improve, rather than diminish, the ecosystem services provided by woodlands in rowcrop-dominated landscapes.

Powering America: The impact of ethanol production in the Corn Belt states

This paper investigates the impact of ethanol production in the Corn Belt states (Iowa, Indiana, Illinois, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, Ohio, South Dakota, and Wisconsin). Employing data at the county level, from 2005 to 2006, we investigate the effect of ethanol production on employment and wages. Our empirical results show that ethanol production has a positive significant effect on employment and wages, but this effect is of insignificant magnitude. We also find that counties with high and medium levels of ethanol production capacity show higher levels of employment and wages than those counties that do not produce ethanol. Counties with low levels of ethanol production do not show any significant difference in employment and wages than non-producing ethanol counties.

Assessing corn stover composition and sources of variability via NIRS

Corn stover, the above-ground, non-grain portion of the crop, is a large, currently available source of biomass that potentially could be collected as a biofuels feedstock. Biomass conversion process economics are directly affected by the overall biochemical conversion yield, which is assumed to be proportional to the carbohydrate content of the feedstock materials used in the process. Variability in the feedstock carbohydrate levels affects the maximum theoretical biofuels yield and may influence the optimum pretreatment or saccharification conditions. The aim of this study is to assess the extent to which commercial hybrid corn stover composition varies and begin to partition the variation among genetic, environmental, or annual influences. A rapid compositional analysis method using near-infrared spectroscopy/partial least squares multivariate modeling (NIR/PLS) was used to evaluate compositional variation among 508 commercial hybrid corn stover samples collected from 47 sites in eight Corn Belt states after the 2001, 2002, and 2003 harvests. The major components of the corn stover, reported as average (standard deviation) % dry weight, whole biomass basis, were glucan 31.9 (2.0), xylan 18.9 (1.3), solubles composite 17.9 (4.1), and lignin (corrected for protein) 13.3 (1.1). We observed wide variability in the major corn stover components. Much of the variation observed in the structural components (on a whole biomass basis) is due to the large variation found in the soluble components. Analysis of variance (ANOVA) showed that the harvest year had the strongest effect on corn stover compositional variation, followed by location and then variety. The NIR/PLS rapid analysis method used here is well suited to testing large numbers of samples, as tested in this study, and will support feedstock improvement and biofuels process research.