Cover crops and weed suppression in the U.S. Midwest: A meta‐analysis and modeling study

Abstract In addition to soil health and conservation benefits, cover crops (CCs) may offer weed control in the Midwestern United States (Midwest), but individual studies report varying effects. We conducted a meta-analysis of studies measuring weed biomass (WBIO) or density (WDEN) in paired CC and no-cover treatments in maize (Zea mays)-soybean (Glycine max) rotations in the Midwest. Fifteen studies provided 123 paired comparisons of WBIO and 119 of WDEN. Only grass CCs significantly reduced WBIO, while no CC reduced WDEN. We found no evidence CC management factors (e.g. termination method) directly impacted outcomes. Our dataset showed a 75% reduction in WBIO requires ≥5 Mg ha-1 of CC. Simulations from a process-based model (SALUS) indicated achieving 5 Mg ha-1 requires substantially earlier fall planting and later spring termination in most years, conflicting with typical cash-crop planting and harvesting. We conclude CCs significantly reduce WBIO, but current CC management constraints render these reductions variable and uncertain.

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Faculty Opinions recommendation of Behavioral counseling after screening for alcohol misuse in primary care: a systematic review and meta-analysis for the U.S. Preventive Services Task Force.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717958774.793464360 ◽

2012 ◽

Author(s):

Evgeny Krupitsky ◽

Elena Blokhina

Keyword(s):

Systematic Review ◽

Primary Care ◽

Alcohol Misuse ◽

Task Force ◽

Meta Analysis ◽

Preventive Services ◽

Behavioral Counseling ◽

The U.S

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Faculty Opinions recommendation of Behavioral counseling after screening for alcohol misuse in primary care: a systematic review and meta-analysis for the U.S. Preventive Services Task Force.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717958774.793463955 ◽

2012 ◽

Author(s):

George Woody

Keyword(s):

Systematic Review ◽

Primary Care ◽

Alcohol Misuse ◽

Task Force ◽

Meta Analysis ◽

Preventive Services ◽

Behavioral Counseling ◽

The U.S

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Stable Characteristics of Cover Crops for Weed Suppression in Organic Farming Systems

Plant Production Science ◽

10.1626/pps.14.75 ◽

2011 ◽

Vol 14 (1) ◽

pp. 75-85 ◽

Cited By ~ 18

Author(s):

Hiroshi Uchino ◽

Kazuto Iwama ◽

Yutaka Jitsuyama ◽

Keiko Ichiyama ◽

Eri Sugiura ◽

...

Keyword(s):

Organic Farming ◽

Cover Crops ◽

Farming Systems ◽

Weed Suppression ◽

Organic Farming Systems

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Spring-planted cover crops for weed control in soybean

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000107 ◽

2021 ◽

pp. 1-8

Author(s):

Katja Koehler-Cole ◽

Christopher A. Proctor ◽

Roger W. Elmore ◽

David A. Wedin

Keyword(s):

Weed Control ◽

Biomass Production ◽

Cover Crops ◽

Weed Management ◽

Block Design ◽

Weed Suppression ◽

Crop Species ◽

Cold Temperatures ◽

Weed Biomass ◽

Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

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Assessing the impacts of cover crops on maize and soybean yield in the U.S. Midwestern agroecosystems

Field Crops Research ◽

10.1016/j.fcr.2021.108264 ◽

2021 ◽

Vol 273 ◽

pp. 108264

Author(s):

Ziqi Qin ◽

Kaiyu Guan ◽

Wang Zhou ◽

Bin Peng ◽

María B. Villamil ◽

...

Keyword(s):

Cover Crops ◽

Soybean Yield ◽

The U.S

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Examining the Association and Directionality between Mental Health Disorders and Substance Use among Adolescents and Young Adults in the U.S. and Canada—A Systematic Review and Meta-Analysis

Journal of Clinical Medicine ◽

10.3390/jcm7120543 ◽

2018 ◽

Vol 7 (12) ◽

pp. 543 ◽

Cited By ~ 9

Author(s):

Sarvenaz Esmaeelzadeh ◽

John Moraros ◽

Lilian Thorpe ◽

Yelena Bird

Keyword(s):

Mental Health ◽

Systematic Review ◽

Substance Use ◽

Young Adults ◽

Meta Analysis ◽

Mental Health Disorders ◽

Adolescents And Young Adults ◽

Health Disorders ◽

The U.S

Background: The purpose of this systematic review was to examine the association and directionality between mental health disorders and substance use among adolescents and young adults in the U.S. and Canada. Methods: The following databases were used: Medline, PubMed, Embase, PsycINFO, and Cochrane Library. Meta-analysis used odds ratios as the pooled measure of effect. Results: A total of 3656 studies were screened and 36 were selected. Pooled results showed a positive association between depression and use of alcohol (odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.24–1.83), cannabis (OR = 1.29, 95% CI: 1.10–1.51), and tobacco (OR = 1.65, 95% CI: 1.43–1.92). Significant associations were also found between anxiety and use of alcohol (OR = 1.54, 95% CI: 1.19–2.00), cannabis (OR = 1.36, 95% CI: 1.02–1.81), and tobacco (OR = 2.21, 95% CI: 1.54–3.17). A bidirectional relationship was observed with tobacco use at baseline leading to depression at follow-up (OR = 1.87, CI = 1.23–2.85) and depression at baseline leading to tobacco use at follow-up (OR = 1.22, CI = 1.09–1.37). A unidirectional relationship was also observed with cannabis use leading to depression (OR = 1.33, CI = 1.19–1.49). Conclusion: This study offers insights into the association and directionality between mental health disorders and substance use among adolescents and young adults. Our findings can help guide key stakeholders in making recommendations for interventions, policy and programming.

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Integration of cover crops and fertilizer rates for weed management in celery

Weed Science ◽

10.1614/ws-05-078r.1 ◽

2006 ◽

Vol 54 (02) ◽

pp. 326-334 ◽

Cited By ~ 9

Author(s):

Kevin S. Charles ◽

Mathieu Ngouajio ◽

Darryl D. Warncke ◽

Kenneth L. Poff ◽

Mary K. Hausbeck

Keyword(s):

Soil Fertility ◽

Cover Crops ◽

Weed Management ◽

Weed Suppression ◽

Fertility Level ◽

Hairy Vetch ◽

Bare Ground ◽

Weed Biomass ◽

Cereal Rye ◽

Oilseed Radish

Field studies were carried out in Laingsburg, MI, from 2002 to 2004 on Houghton muck soil to assess the impacts of cover crops and soil fertility regimes on weed populations and celery yield. The cover crops were oilseed radish, cereal rye, hairy vetch, and a bare ground control. The fertility rates were full (180, 90, and 450 kg ha−1nitrogen [N], phosphorus pentoxide [P2O5], and potassium oxide [K2O], respectively), half (90, 45, and 225 kg ha−1N, P2O5, and K2O, respectively), and low (90 kg ha−1N). Each cover crop treatment was combined with the low or half rate of fertilizer. An additional treatment with bare ground plus the full rate of fertilizer was added as standard practice. Treatments were maintained in the same location for the duration of the study. Major weed species were common chickweed, prostrate pigweed, shepherd's-purse, common purslane, and yellow nutsedge. Each year, oilseed radish consistently produced the greatest biomass and provided over 98% early season weed biomass suppression. Hairy vetch and cereal rye provided about 70% weed suppression in early spring. Soil fertility level affected weed populations during the 2004 growing season. In 2004, weed biomass in treatments without cover crops or with vetch increased when greater amounts of fertilizer were applied. Within individual fertility levels, higher celery yields were recorded in the oilseed radish plots. For example, in the low fertility rate, celery yield was 34.8, 29.2, 23.9, and 24.4 ton ha−1in the oilseed radish, cereal rye, hairy vetch, and control plots, respectively in 2003. Overall, the results of this experiment indicate that when included in a system where hoeing and hand-weeding are the only weed control methods, cover crops can successfully improve weed management and celery yield on muck soils, allowing reduced fertilizer inputs.

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Sample-Selection Biases and the Industrialization Puzzle

The Journal of Economic History ◽

10.1017/s0022050717000031 ◽

2017 ◽

Vol 77 (1) ◽

pp. 171-207 ◽

Cited By ~ 46

Author(s):

Howard Bodenhorn ◽

Timothy W. Guinnane ◽

Thomas A. Mroz

Keyword(s):

United States ◽

Selection Bias ◽

Meta Analysis ◽

Sample Selection ◽

Well Being ◽

The United States ◽

Compelling Evidence ◽

Long Term Changes ◽

The U.S

Understanding long-term changes in human well-being is central to understanding the consequences of economic development. An extensive anthropometric literature purports to show that heights in the United States declined between the 1830s and the 1890s, which is when the U.S. economy modernized. Most anthropometric research contends that declining heights reflect the negative health consequences of industrialization and urbanization. This interpretation, however, relies on sources subject to selection bias. Our meta-analysis shows that the declining height during industrialization emerges primarily in selected samples. We also develop a parsimonious diagnostic test that reveals, but does not correct for, selection bias in height samples. When applied to four representative height samples, the diagnostic provides compelling evidence of selection.

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