Agricultural & Environmental Letters最新文献

Field plot experiments were conducted over 3 years at two farm sites in Vermont to evaluate the effects of mechanical subsoiling and three pasture cropping mixes on soil compaction across rotationally grazed pasturelands with contrasting management histories in Vermont. Penetration resistance was measured across the 0–45.7 cm profile using both profile-level and depth-stratified analyses. Among the biological treatments, the sudangrass-based mix achieved the greatest compaction alleviation, particularly at the site with higher initial severity. At the northern site (Health Hero [HH] Farm), this mix produced significantly lower median penetration resistance (1.59 MPa) and a narrower interquartile range (0.93 MPa) than other treatments, indicating more uniform soil improvement. At the southern site (Philo Ridge [PR] Farm), keyline plowing resulted in the lowest median resistance (1.41 MPa) but showed greater variability across replicates. Depth-wise trends revealed that biological mixes, particularly the sudangrass-based mix, provided consistent alleviation across soil layers. These findings highlight the value of biologically tailored strategies not only for reducing compaction but also for achieving spatially uniform soil structure recovery. Tailoring species composition to compaction depth offers a practical and lower disturbance alternative to mechanical tillage for improving pasture systems.

The socioeconomic value of content presented at the ASA-CSSA-SSSA (where ASA-CSSA-SSSA is American Society of Agronomy–Crop Science Society of America–Soil Science Society of America) Annual Meetings from 2014 to 2023 is estimated at $64.2 billion and is presented in this commentary as a thought exercise, highlighting the potential scale of research dissemination in scientific meetings. Scientific meetings are instrumental for propelling the quality and advancement of research via fostering timely feedback, knowledge dissemination, fresh perspectives, stimulation for networking and new collaborations, preparing scientists for public engagement, and addressing contemporary challenges of cultural accessibility and opportunity. Additionally, the broader impacts include near-term benefits to agricultural and environmental scientists that can transform careers and perspectives on the world, especially for students and early career members. The benefits from these impacts on scientists are then anticipated to propagate into broader and longer term positive impacts on humanity worldwide. In this commentary, we offer the above as a provocation to spark peer discussion on evaluating scientific meetings’ contributions, alongside a working list of broader impacts to inspire philosophical and methodological innovations for quantifying their value.

Long-term experiments (LTEs) offer unique insights into the effects of agricultural practices on soil organic carbon (SOC). However, early LTEs commonly lack treatment randomization, replication, and initial measurements of SOC. This creates a potential problem of unmeasured confounding. We address this problem using the Morrow Plots (established 1876) as a case study. We start with a standard mixed effects model of SOC and add (i) a spatial kriging component and (ii) SOC measurements in the sod perimeter of the experiment as an additional treatment level. We find that much of the observed SOC variation between treatments after 145 years is not due to treatments but other factors (e.g. initial SOC), attenuating treatment effects by about 50%. Our study demonstrates that creative measurement and innovative modeling can mitigate some deficiencies in early LTEs. However, our improved estimates still have limited precision, suggesting the importance of careful design and measurement in the first place.

The Fertilizer Recommendation Support Tool (FRST) Project is a collaborative effort involving most land grant institutions, USDA branches, nonprofit organizations, and private industry. The FRST objectives are to develop a soil fertility community of practice, preserve soil test correlation and calibration data in a relational database, and develop a decision tool to provide consistent soil test interpretations. Released in April 2024, the interactive tool acts on an evolving database that contained 1455 P trials, 1316 K trials, and 143 S trials from 44 states and Puerto Rico by March 1, 2025. Decision tool outputs include an interactive county-level map of available data and an estimated critical soil test value. The FRST relational database is a repository for soil-test-based P, K, and S data to support data-driven management recommendations. Continued success of the FRST project and decision tool utility rely on collaboration and support from the soil-test-based nutrient management community.

Quizalofop-p-ethyl (QPE) can control glufosinate/glyphosate-resistant corn (Zea mays L.) volunteers in corn resistant to aryloxyphenoxypropionates (Enlist corn). Mixing QPE with broadleaf herbicides such as 2,4-D choline can be antagonistic. A new precision sprayer with a dual tank/boom system can apply two herbicides simultaneously through separate nozzles, potentially reducing chemical antagonism. The objective of this study was to evaluate the interaction of QPE + 2,4-D choline applied via single tank or dual tank/boom system for controlling glufosinate/glyphosate-resistant corn volunteers in Enlist corn. Bin-run glufosinate/glyphosate-resistant corn was planted at 54,000 seeds ha⁻¹ to mimic corn volunteers. At 14 days after application (DAA), the dual tank/boom application of QPE (39 g a.i. ha⁻¹) and 2,4-D choline (1064 g a.e. ha⁻¹) achieved 85% volunteer corn control, compared to 70% control with single tank mix. The single tank application of QPE + 2,4-D choline was 7%–26% antagonistic until 28 DAA. Conversely, dual tank application of QPE and 2,4-D choline was additive. Although dual tank application of QPE and 2,4-D choline did not have transient antagonism (14 DAA), it was otherwise eliminated by 28 DAA using the higher rate of QPE (77 g a.i. ha⁻¹) in the tank mix. By 28 DAA, volunteer corn control was ≥92% across all treatments, with similar corn yield and no crop injury. The results suggest that a dual tank/boom system provided better volunteer corn control at 14 DAA; however, control was similar when using a higher rate of QPE (77 g a.i. ha⁻¹) with 2,4-D choline in tank mix at 28 DAA.

Soil management assessment framework (SMAF) algorithms have not been validated for tropical soils, which can prevent proper SMAF-based soil health monitoring. This study tested SMAF's ability to detect soil health as affected by soil management practices in the Mid-South United States and Brazil for improving SMAF performance in tropical regions. Eleven SMAF studies published in Brazil (n = 166) and 56 from the Mid-South United States (n = 500) were compiled. Management groups were perennial (PER), no-till (NT), reduced tillage (RT), and conventional tillage (CT) systems. In the United States, SMAF soil quality index decreased as follows: PER ≥ RT ≥ NT = CT, while for Brazil, PER > NT = RT = CT. Macroaggregate and microbial biomass carbon scores under CT were overestimated, resulting in nonsignificant differences between conservation and conventional soil management. Revision of organic matter and textural parameters is needed to improve SMAF utilization in tropical agroecosystems.