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Abstract The transition from conventional to more regenerative cropping systems can be economically risky due to variable transition period yields and unforeseen costs. We compared yields and economic returns for the first 3 years of the transition from a business as usual (BAU) conventional corn (Zea mays)–soybean (Glycine max) rotation to an aspirational (ASP) five‐crop (corn‐soybean‐winter wheat [Triticum aestivum]–winter canola [Brassica napus]‐forage) rotation in the Upper Midwest United States. Regenerative ASP cropping practices included the more diverse crop rotation, continuous no‐till, cover crops, precision inputs, and livestock (compost) integration. For the first two transition years, BAU corn yields were 8%–12% higher than ASP while in the third transition year, BAU corn yields were 5% lower. Soybean yields were similar for the first 2 years but higher in BAU in the third year due to an ASP pest outbreak. Equivalent yields for other ASP crops were lower than BAU in the first 2 years but similar in the third year except for canola, which suffered from slug damage. Whole‐system economic returns narrowed across years; by year three, whole system comparisons for the ASP corn and soybean entry points (corn‐soybean‐wheat and soybean‐wheat‐canola, respectively) showed equivalent economic returns for BAU and ASP, despite yield differences, owing largely to the ASP system's reduced operational costs. Overall findings suggest that early regenerative systems can be as profitable as conventional systems with careful attention to rotation entry points and inputs. 

Abstract BACKGROUNDThis article presents a model of how farmers choose to custom hire for pest control. The decision‐making process is illustrated through a discrete choice experiment conducted via a pilot survey of soybean growers in Michigan, Illinois, and Indiana. Farmers responded to a hypothetical pest infestation by choosing between custom operators, spraying on their own, or leaving the field to its fate. RESULTSAmong farmers who choose to spray, the mean willingness to pay for marginal increases in timeliness (as defined as the chance of late spraying) ranges from 37 to 52 cents per acre. We also find that farmers more averse to risk are more sensitive to custom operator timeliness and that farmers with better‐developed social networks are less sensitive to the risk of delay. CONCLUSIONThe results of this study can motivate future research into the drivers of on‐farm decision‐making, especially as it relates to custom hire behavior in pest control and other field operations. © 2024 The Author(s).Pest Management Sciencepublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 

Abstract Model projections predict increasing temperatures and precipitation change in many locations in the Central United States. To provide perspective on what these trends might bring relative to what has already happened, we compared historical temperature and precipitation change with what models from the Coupled Model Intercomparison Project (CMIP6) predict. The analysis focuses on regions represented by five long‐term agroecosystem research sites along a latitudinal transect from Michigan to Iowa, Missouri, Oklahoma, and Mississippi. We analyzed trends in long‐term records (≥50 years) of precipitation and temperature data at annual and monthly scales using indicators that characterize extreme and average temperature and rainfall amounts. Results show that temperatures have changed from 1900 to 2020, more for minimum (0.1°C–0.3°C decade⁻¹) than maximum (−0.1°C–0.2°C decade⁻¹), more for winter (−0.1°C–0.3°C decade⁻¹) than summer (−0.1°C–0.1°C decade⁻¹), and more often in the north than in the south. Except in Mississippi, annual precipitation has increased at rates of 25 mm decade⁻¹or greater over 1950–2020, but monthly trends were inconsistent. Projected trends suggest continued temperature increases, highlighting the urgent need for research on management systems that are resilient to such increases. 

Abstract Evaluating stream water chemistry patterns provides insight into catchment ecosystem and hydrologic processes. Spatially distributed patterns and controls of stream solutes are well‐established for high‐relief catchments where solute flow paths align with surface topography. However, the controls on solute patterns are poorly constrained for low‐relief catchments where hydrogeologic heterogeneities and river corridor features, like wetlands, may influence water and solute transport. Here, we provide a data set of solute patterns from 58 synoptic surveys across 28 sites and over 32 months in a low‐relief wetland‐rich catchment to determine the major surface and subsurface controls along with wetland influence across the catchment. In this low‐relief catchment, the expected wetland storage, processing, and transport of solutes is only apparent in solute patterns of the smallest subcatchments. Meanwhile, downstream seasonal and wetland influence on observed chemistry can be masked by large groundwater contributions to the main stream channel. These findings highlight the importance of incorporating variable groundwater contributions into catchment‐scale studies for low‐relief catchments, and that understanding the overall influence of wetlands on stream chemistry requires sampling across various spatial and temporal scales. Therefore, in low‐relief wetland‐rich catchments, given the mosaic of above and below ground controls on stream solutes, modeling efforts may need to include both surface and subsurface hydrological data and processes. 

Abstract Greenhouse gas (GHG) emissions reduction efforts are underway to mitigate climate change worldwide. Climate‐smart agriculture (CSA) practices have been shown to both increase soil organic carbon (SOC) inputs and reduce net greenhouse gas emissions (GHGnet). We evaluated the GHGnet of several management practices with three biogeochemical models (APSIM, Daycent, and RothC) at two sites with contrasting soils, climates, and cropping systems. Additionally, two future climate scenarios (baseline and high‐emissions) provided alternative outcomes of SOC, N₂O, and CH₄by 2050. In Michigan, most biochar and residue retention with no‐till treatments increased SOC stocks; leguminous cover crops, no‐till, and reducing fertilizer input lowered N₂O emissions. The lowest biochar treatment lowered GHGnet in the baseline climate scenario, but all other management treatments increased GHGnet under both baseline and high emissions, and all management scenarios increased a mean of 8.0 Mg CO₂‐equivalent GHG (CO₂e) ha⁻¹from baseline to high emissions. Conversely, in Texas, most treatments increased SOC, and N₂O was relatively constant. Every no‐till treatment reversed GHGnet in both the baseline and high‐emissions climate scenarios but all management scenarios increased a mean of 0.6 Mg CO₂e ha⁻¹under high emissions. At both sites under high‐emissions climate change, cover crops and no‐till resulted in the lowest GHGnet overall. Overall, the study showed that no‐till, especially with residue retention, and cover crops are important CSA practices to lower the GHGnet of agriculture, but there remains much room to find even more effective solutions to adapt to climate change. 

Abstract The relationship between diversity and stability remains a key question in ecology and has important consequences for understanding the sustainability (and profitability) of bioenergy cropping systems; yet to date, little work has been done to examine these relationships in agricultural systems directly. In this study, we evaluated the relationship between biodiversity (in number of planted species) and the stability of biomass production in four experimental bioenergy cropping systems established in Wisconsin and Michigan. Species composition and aboveground production were monitored at all sites for 8–10 years (2010–2019) allowing us to evaluate the temporal stability of biomass yield (defined as the temporal mean divided by the temporal SD) in these cropping systems. A major regional drought in 2012 also allowed us to evaluate resistance and resilience. Although three of the cropping systems were established with the same seed mixtures and were managed in the same way, species composition differed markedly between sites. This limited our ability to attribute differences within cropping systems across sites to the abundance of specific species. Overall, there was no clear relationship between planted species richness and yield stability in biomass production at these sites. At both sites, the lowest diversity system (switchgrass monoculture) had the highest interannual stability in production and was equivalent to that of the highest diversity treatment (prairie). Resilience to the drought was high in all treatments and did not differ among the four cropping systems; however, resistance to drought differed among systems and was highest in the switchgrass monocultures at both sites. The abundance of perennial C₄grasses increased over time in all cropping systems, except for the successional plots. The persistence of annual species in the successional treatments at both sites likely contributed to low stability and high interannual turnover in this system. We found no evidence that increasing the diversity of planted species in bioenergy cropping systems enhances stability in aboveground biomass production; nor was there any difference in resistance or resilience to drought. The higher costs of establishing more diverse bioenergy cropping systems may be warranted if other ecosystem services, such as supporting diverse pollinator and predator insect species at the landscape scale, are desired from bioenergy crops in addition to biomass production. 

ABSTRACT Switchgrass (Panicum virgatumL.) is a native North American grass currently considered a high‐potential bioenergy feedstock crop. However, previous reports questioned its effectiveness in generating soil organic carbon (SOC) gains, with resultant uncertainty regarding the monoculture switchgrass's impact on the environmental sustainability of bioenergy agriculture. We hypothesize that the inconsistencies in past SOC accrual results might be due, in part, to differences in prior land management among the systems subsequently planted to switchgrass. To test this hypothesis, we measured SOC and other soil properties, root biomass, and switchgrass growth in an experimental site with a 30‐year history of contrasting tillage and N‐fertilization treatments, 7 years after switchgrass establishment. We determined switchgrass' monthly gross primary production (GPP) for six consecutive years and conducted deep soil sampling. Nitrogen fertilization expectedly stimulated switchgrass growth; however, a tendency for better plant growth was also observed under unfertilized settings in the former no‐till soil. In topsoil, SOC significantly increased from 2007 to 2023 in fertilized treatments of both tillage histories, with the greatest increase observed in fertilized no‐till. Fertilized no‐till also had the highest particulate organic matter content in the topsoil, with no differences among the treatments observed in deeper soil layers. However, regardless of fertilization, the tillage history had a strong effect on stratification with depth of SOC, total N, and microbial biomass C. Results suggested that historic and ongoing N fertilization had a substantial impact on switchgrass growth and soil characteristics, while tillage legacy had a much weaker, but still discernible, effect. 

ABSTRACT In order to better predict climate change effects on plants and their communities, we need to improve our understanding of how various plant traits and community properties respond to warming, as well as what contexts contribute to variation in these responses. To address this knowledge gap, we compiled data from 126 in situ passive experimental warming studies on 13 different plant trait and community property responses. We then collected metadata from these studies to define 9 different study contexts spanning environmental, experimental, and plant‐level scales. We find that, globally, some traits decrease when warmed (e.g., aboveground N content), while others increase (e.g., plant biomass). We also identify contexts that contribute to variation in plant responses to warming, such as latitude, distance from northern range edge, and plant functional group, but the importance of these contexts varies based on the trait or community property measured. For example, as latitude increases, the effect of warming on reproductive traits becomes stronger, but this latitude‐trait relationship did not hold for all traits. Our study highlights how multiple plant traits and community properties respond to warming across the globe, the importance of carefully designing and interpreting the outcomes of climate change experiments, and the need for coordinated warming experiments across varying environmental contexts in order to mechanistically understand and predict plant community responses to climate warming. 

Abstract Reducing tillage is a key goal for conservation and regenerative agriculture, yet research has struggled to identify ways to increase the use of the practice among farmers. Recent scholarship has identified social capital as an important piece of the adoption puzzle. However, the ways in which farmers' social capital influences conservation practice use are seldom identified or explored. In this study, we tested the effects of three measures of social capital on the adoption of no‐till among 1,523 row crop farmers in the United States Corn Belt. Specifically, we operationalized the extent to which farmers' social networks, network trust, and community conservation norms affect intra‐individual processes and thus influence farmers' decisions regarding adoption. Our results identified key mechanisms for the promotion of conservation practices through social capital. Subjective conservation norms emerged as a main pathway through which farmers' social capital influenced their use of no‐till, indicating that networks, network trust, and community norms can increase adoption through affective paths. We conclude that academic research and policy experts should continue to situate farmers as social actors and pay heed to the norms and cultural expectations surrounding agricultural conservation practices. 

Abstract Delineation of microbial habitats within the soil matrix and characterization of their environments and metabolic processes are crucial to understand soil functioning, yet their experimental identification remains persistently limited. We combined single- and triple-energy X-ray computed microtomography with pore specific allocation of¹³C labeled glucose and subsequent stable isotope probing to demonstrate how long-term disparities in vegetation history modify spatial distribution patterns of soil pore and particulate organic matter drivers of microbial habitats, and to probe bacterial communities populating such habitats. Here we show striking differences between large (30-150 µm Ø) and small (4-10 µm Ø) soil pores in (i) microbial diversity, composition, and life-strategies, (ii) responses to added substrate, (iii) metabolic pathways, and (iv) the processing and fate of labile C. We propose a microbial habitat classification concept based on biogeochemical mechanisms and localization of soil processes and also suggests interventions to mitigate the environmental consequences of agricultural management.