In the US upper Midwest, the narrow growing season causes many farmers to presume yield losses when reducing tillage. The purpose of this study was to determine how four production-scale tillage systems affected residue cover, stand populations, crop yields, and soil chemical, biological, and physical properties. Tillage systems (chisel plow, fall strip-till with shanks, spring strip-till with coulters, and shallow vertical till) were continued for 4 yr. Tillage effects within a site were few and mixed (0.17-0.36 Mg ha-1 difference), whereas site effects were common (0.50-3.00 Mg ha-1 difference). Among 19 soil properties, only fungal/bacteria ratios differed among strip-till with shanks (0.078) and strip-till with coulters (0.066) at one site. Our results suggest that many farmers' concerns about using conservation tillage practices do not necessarily translate into yield losses when compared to standard chisel plow practices. Economics and the level of erosion control among the tillage practices compared here, rather than yield alone, should guide farmer preferences.
Economic projections after widespread deep compaction during wet harvests are essentially nonexistent. Therefore, we project state‐level economic costs to producers in North Dakota and Minnesota for the upcoming 2020 and 2021 crops. We provide economic cost graphs as functions of grain sell prices and fractions of land impacted by deep wheel‐traffic compaction. At corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] sell prices of US$3.06 bu−1 and $8.78 bu−1 for North Dakota and $3.26 bu−1 and $8.98 bu−1 for Minnesota, we estimate a minimum economic cost of US$587 million through 2021, excluding environmental externalities and other feedbacks, for every 10% of lands compacted during the 2019 harvest. Actual impacted land area may range up to 30%, resulting in a range of US$0 to $1.76 billion of actual costs. Precise large‐scale, deep‐compaction reports/sensing is needed to determine actual fractions of impacted land. Policies incentivizing conservation practices to reduce the occurrence of field traffic on wet soils are strongly encouraged.
Near-surface soil water content (SWC) and its spatial patterns are important for landscape hydrological responses to precipitation as well as our ability to remotely sense and model such responses. Our objective was to measure and evaluate near-surface SWC semivariograms of agricultural fields with newly imposed (i.e., <2 yr) side-by-side soil and residue management practices (i.e., reduced tillage systems and cover crops) in the midwestern United States. Range parameters were consistently smaller when cover crops were planted (20-25 m less) and tillage area and/or intensity was reduced (12-27 m less) compared with no cover crop and chisel plowing, respectively, except in a clayey Vertisol. Nugget and sill parameters did not have consistent trends across soil management practices or sites. These data, although brief and preliminary in scope, provide clear proof of concept that spatial pattern shifts can be clearly detected in newly imposed soil-management systems even though differences in SWC means are not always evident.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.