Agricultural & Environmental Letters最新文献

Farmers are increasingly planting cover crops to improve soil health and provide other ecosystem services. Cover crop incentive programs in Maryland, Pennsylvania, New York, and Vermont were compared and farmers using cover crops were surveyed (n = 328) to characterize program participants and assess the effects of programs on cover crop adoption. Farmers who participated in incentive programs differed from nonparticipants in their perspectives about incentive programs, challenges they faced using cover crops, and reasons for cover crop use. When averaged across farmers, results show that incentive programs doubled average farmer cropland with cover crops from 50.7 ha prior to participation to 101.0 ha during participation. Among participants who no longer were enrolled in a program, cover crop use remained on average 37.2% greater than before enrollment. Results highlight the role of incentive programs in facilitating adoption and provide insights for expanding participation to different farmers and increasing program impact.

Robust assessment of crop water availability requires effective integration of soil moisture data within the range of field capacity (θ_FC) to permanent wilting point (θ_PWP). Emerging needs for spatiotemporally dynamic θ_FC and θ_PWP are difficult to achieve with lab determinations. Therefore, we used long-term data from 182 sites across the United States to evaluate whether soil moisture extremes defined by 95th and 5th percentiles represent θ_FC and θ_PWP, respectively. Soil moisture extremes and lab-measured θ_FC and θ_PWP were well correlated (R² = 0.71−0.92), however, both 95th and 5th percentiles overestimated θ_FC and θ_PWP at most depths (RMSE = 6%–16% vwc). Percentiles of soil moisture distribution that corresponded to lab-determined θ_FC and θ_PWP varied widely and were a function of precipitation received at the site and site- and soil-depth specific clay content. These findings imply that while θ_FC and θ_PWP may not be broadly represented by soil moisture extremes (95th and 5th percentiles), there may be potential to statistically infer the positioning of θ_FC and θ_PWP within long-term soil moisture distributions using biophysical determinants such as aridity and soil characteristics.

Many peatlands have been drained for anthropogenic purposes, and there is high interest in restoring them for their carbon storage ability and critical habitat. Peatlands hold a disproportionate amount of global soil carbon, making peatland restoration a promising approach for mitigating carbon emissions. In this study, site factors were investigated that affect peat carbon dioxide flux at Cold Spring fen in Minnesota, which is undergoing restoration. Peat carbon dioxide flux and water table depth were monitored throughout the growing season at two locations previously disturbed to different degrees by row-crop agriculture. Flux ranged from 0.55 to 12.71 µmol m⁻² s⁻¹ and was highest during peak growing season. Lower flux corresponded to elevated water table conditions. The more disturbed location often had lower flux, indicating success in hydrological restoration. The water table is an important factor in peatland restoration, and water table management should be considered to maximize carbon sequestration.

Permanganate oxidizable carbon (POXC) is a popular soil health test developed to measure “labile” C via the reduction of permanganate, dependent on several stoichiometric reduction oxidation assumptions. As a proof-of-concept experiment to evaluate the interpretation of POXC as “labile” C, we tested 17 compounds ranging in biological lability under standard POXC assay conditions at a fixed C mass (25 mg) in a quartz (2–0.053 mm diameter) matrix. POXC was high for lignin, whereas carbohydrates did not differ from the quartz control. Functional group-based reactivity partly explained permanganate reduction. These findings indicate that (i) POXC is not a labile C fraction and (ii) corroborate previous concerns that the stoichiometric oxidation–reduction assumptions in the calculation of C oxidation from permanganate reduced are not sound. POXC interpretation should regard POXC as a chemically defined fraction, report in units of moles permanganate reduced per kg soil, and avoid terms such as “labile” and “active.”

Living mulch (LM) is used in agricultural fields to suppress weeds, control diseases, and mitigate erosion. It also enhances soil nutrient supply at the root death and decay stage during the growing season. However, benefits of LM to soil hydraulic properties related to soil pore structure have not been elaborated here. We focus on temporal changes in soil hydraulic conductivity (K) in a field where sweet potato was grown with and without LM (barley, Hordeum vulgare L.). K was measured in the field using a mini-disk infiltrometer at three different pressure heads. In the plots with LM, K decreased significantly in August and then increased in October compared to plots without LM (at –0.5 cm pressure head). Changes in soil pore structure due to root growth or death and decay may alter soil hydraulic conductivity.

Maintaining the editorial standards of a scientific journal is the primary task of the journal editors. Their task is made much easier with the help of colleagues who are invited to review manuscripts. Through their critical comments and helpful suggestions, these volunteer reviewers have done much to maintain and further the quality of research reported in Agricultural Letters & Environmental Letters. The members of the Agricultural Letters & Environmental Letters Editorial Board express their appreciation to the following individuals who reviewed manuscripts in 2022. Many of the reviewers listed below reviewed more than one manuscript. We extend our apologies and thanks to those reviewers whose names have been inadvertently omitted from this list.

Acosta-Martinez, Veronica, USDA-ARS

Archer, David, USDA-ARS-NGPRL

Bardhan, Sougata, Lincoln University of Missouri

Basche, Andrea, University of Nebraska-Lincoln

Belasco, Eric

Brorsen, Wade, Oklahoma State University

Bryant, Ray, USDA-ARS-Pasture Systems and Watershed Management Research Unit

Buda, Anthony, USDA-ARS

Castellano, Michael, Iowa State University

Cates, Anna, University of Minnesota Twin Cities

Chakraborty, Debolina, University of Florida

Cheng, Weiguo, Yamagata University

Cheong, Kit-Leong

Clemensen, Andrea

Collick, Amy, Morehead State University

Culman, Steven, Washington State University

Daigh, Aaron, University of Nebraska-Lincoln

De Guzman, Christian, University of Arkansas System

Dell, Curtis, USDA-ARS Pasture Systems and Watershed Management Research Unit

DeSutter, Thomas, North Dakota State University

Devkota, Pratap, University of Florida

Dungan, Robert, USDA-ARS

Elnaker, Nancy, Khalifa University

Essington, Michael, University of Tennessee

Ewing, Patrick, USDA-ARS North Central Agricultural Research Laboratory

Farmaha, Bhupinder, Clemson University

Faulkner, Joshua, University of Vermont

Francisco, Eros

Franzen, David, North Dakota State University

Franzluebbers, Alan, USDA

Gailans, Stefan, Practical Farmers of Iowa

Gatiboni, Luke, North Carolina State University at Raleigh

Ghanem, Michel Edmond, ITK

Ghimire, Rajan, New Mexico State University

Ginakes, Peyton, University of Maine System

Good, Laura, University of Wisconsin-Madison

Graham, Jennifer, US Geological Survey Northeast Region

Guo, Mingxin, Delaware State University

Haden, Ryan, The Ohio State University

Hatfield, Jerry, USDA-ARS

Hawkesford, Malcolm J., Rothamsted Res

He, Zhongqi, USDA-ARS

Heilman, Philip, USDA-ARS

Joshi, Deepak, South Dakota State University

Kharel, Tulsi, USDA-ARS

Knappenberger, Thorsten, Auburn University

Kral-O'Brien, Katherine, North Dakota University System

Kukal, Meetpal, Pennsylvania State

The Agricultural & Environmental Letters (A&EL) editorial board has selected two individuals for recognition for excellence in performing their work as associate editors. The recognition is based on their efforts in establishing a quality review process—for timely and professional manuscript editing, for fair and rigorous integration of reviewer comments, and for overall excellence in managing a professional review process. The editorial board has also awarded three individuals the Editor's Citation for Excellence in Review. Members of the A&EL editorial board express their deepest appreciation for these associate editors and volunteer reviewers, who have benefited our journal, our community, and our sciences through their outstanding work.

Soil health practices can improve soil conditions and provide ecosystem services, but increased risk of phosphorus (P) loss can be an unintended consequence. We investigated conservation tillage and cover crops effects on soil P stratification, P accumulation at depth, and soil aggregation for sandy Coastal Plain soils from the Mid-Atlantic United States soil cores from 10 agricultural fields with 0–15 years of conservation tillage or cover cropping were analyzed for Mehlich-3 P and dry aggregate stability. We found no evidence that conservation tillage or cover cropping caused P stratification or accumulation in study fields that were already enriched with P prior to soil health implementation. Annual particulate, dissolved runoff, and leachate P loads decreased when estimated using the North Carolina Phosphorus Loss Assessment Tool assuming no-till and cover crops (soil health) compared to conventional till and winter fallow (conventional). We suggest that soil health practices are unlikely to exacerbate P losses from high P Coastal Plain soils beyond their initial risk profile.

Few studies have addressed whether in-field practices to reduce nitrate-nitrogen (NO₃-N) leaching might increase nitrous oxide (N₂O) emissions, which could undermine attempts to mitigate agricultural N pollution. Over a 3-year period, we assessed the impacts of N application timing and cereal rye (Secale cereale L.) cover crop on subsurface drainage NO₃-N leaching and N₂O emissions to quantify changes in total N loss and corresponding social and environmental damage costs under continuous corn (Zea mays L.). While NO₃-N losses were reduced by 37% with the combination of in-season split N application and cereal rye cover crop relative to pre-season N application, soil N₂O emissions increased by 26%, highlighting a tradeoff between N loss pathways. As a result, total N losses and social and environmental damage costs from each system were not different. These results demonstrate the importance of addressing agricultural N pollution using a holistic framework accounting for the environmental and social risks of both NO₃-N losses and N₂O emissions.

Raman spectroscopy (RS) is a vibrational spectroscopy. This work reported the RS spectral characteristics of fiber and seed of six cotton (Gossypium sp.) genotypes differing in fiber length. While the RS spectra of fiber samples were dominated by the cellulose-related peaks, the spectra of cottonseed samples were featured by the bands related to oil, protein, carbohydrate, and lignin components. Principal component analysis (PCA) revealed that the first two principal components (PCs) accounted for >87% of the total variation of the two types of samples. The PC1 versus PC2 plot classified the six fiber samples into three groups, but their cottonseeds into four groups. This experimental evidence implied the possibility of RS combined with PCA for rapid fiber phenotyping of cotton as well as for evaluating cottonseed nutrient information.