Tag: Menalled Lab

Collaborative paper published on winter wheat, farming practices, and climate!

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The second paper from Tindall’s master’s work at Montana State University in the Menalled Lab has been accepted for publication! Tindall defended her master’s in August 2021, and has been working at a plant production company in Bozeman since then.

Ouverson, T., Boss, D., Eberly, J., Seipel, T.,  Menalled, F.D., Ishaq, S.L. 2022. Soil  bacterial community response to cover crops, cover crop termination, and predicted climate conditions in a dryland cropping system. Frontiers in Sustainable Food Systems.

Abstract

Soil microbial communities are integral to highly complex soil environments, responding to changes in aboveground plant biodiversity, influencing physical soil structure, driving nutrient cycling, and promoting both plant growth and disease suppression. Cover crops can improve soil health, but little is known about their effects on soil microbial community composition in semiarid cropping systems, which are rapidly becoming warmer and drier due to climate change. This study focused on a wheat-cover crop rotation near Havre, Montana that tested two cover crop mixtures (five species planted early season and seven species planted mid-season) with three different termination methods (chemical, grazed, or hayed and baled) against a fallow control under ambient or induced warmer/drier conditions. Soil samples from the 2018 and 2019 cover crop/fallow phases were collected for bacterial community 16S rRNA gene sequencing. The presence and composition of cover crops affected evenness and community composition. Bacterial communities in the 2018 ambient mid-season cover crops, warmer/drier mid-season cover crops, and ambient early season cover crops had greater richness and diversity than those in the warmer/drier early season cover crops. Soil microbial communities from mid-season cover crops were distinct from the early season cover crops and fallow. No treatments affected bacterial alpha or beta diversity in 2019, which could be attributed to high rainfall. Results indicate that cover crop mixtures including species tolerant to warmer and drier conditions can foster diverse soil bacterial communities compared to fallow soils.

Figure 1, showing a schematic of the fields and experimental design.

Related works from that research group include:

Collaborative paper accepted on winter wheat, weeds, and climate.

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The last paper to be generated from the large-scale, multi-year, collaborative research I participated in as a postdoc at Montana State University in the Menalled Lab in 2016 has finally been accepted for publication! At the time, I was working on the soil bacteria associated with winter wheat crops under different simulated climate change scenarios, and with added stressors like weed competition and different farming strategies. I was part of a large team of researchers looking at various aspects of agricultural stressors on long-term food production, including several agroecologists who led the development of this paper.

Weed communities in winter wheat: responses to cropping systems and predicted warmer and drier climate conditions.

Tim Seipel, Suzanne L. Ishaq, Christian Larson, Fabian D. Menalled. Sustainability 2022, 14(11), 6880; https://doi.org/10.3390/su14116880. Special Issue “Sustainable Weed Control in the Agroecosystems“

Abstract

Understanding the impact of biological and environmental stressors on cropping systems is essential to secure the long-term sustainability of agricultural production in the face of unprecedented climatic conditions. This study evaluated the effect of increased soil temperature and reduced moisture across three contrasting cropping systems: a no-till chemically managed system, a tilled organic system, and an organic system that used grazing to reduce tillage intensity. Results showed that while cropping system characteristics represent a major driver in structuring weed communities, the short-term impact of changes in temperature and moisture conditions appear to be more subtle. Weed community responses to temperature and moisture manipulations differed across variables: while biomass, species richness, and Simpson’s diversity estimates were not affected by temperature and moisture conditions, we observed a minor but significant shift in weed community composition. Higher weed biomass was recorded in the grazed/reduced-till organic system compared with the tilled-organic and no-till chemically managed systems. Weed communities in the two organic systems were more diverse than in the no-till conventional system, but an increased abundance in perennial species such as Cirsium arvense and Taraxacum officinale in the grazed/reduced-till organic system could hinder the adoption of integrated crop-livestock production tactics. Species composition of the no-till conventional weed communities showed low species richness and diversity, and was encompassed in the grazed/reduced-till organic communities. The weed communities of the no-till conventional and grazed/reduced-till organic systems were distinct from the tilled organic community, underscoring the effect that tillage has on the assembly of weed communities. Results highlight the importance of understanding the ecological mechanisms structuring weed communities, and integrating multiple tactics to reduce off-farm inputs while managing weeds.

The related works from that project include:

Similar work has been done by that group, including:

Tindall defended her master’s thesis!

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Photo of woman in front of mountains

Excitingly, master’s of science graduate student Tindall Ouverson successfully defended her thesis! Tindall is a student at Montana State University, and took over a collaborative project that stretches back when I left my postdoc position (to head to another job) in the Menalled Lab in 2017. Earlier this year, her first scientific paper was published, Temporal soil bacterial community responses to cropping systems and crop identity in dryland agroecosystems of the Northern Great Plains. More recently, she won first prize in the graduate students poster competition at the 2021 Montana State University LRES research colloquium.

Now that she has defended, Tindall will focus on revising the research thesis chapter which was not already published into a manuscript to submit for review at a scientific journal. After that, she is planning on pursuing her career in agricultural sustainability research and outreach.

RESPONSE OF SOIL BACTERIAL COMMUNITIES TO CROPPING SYSTEMS, TEMPORAL CHANGES, AND ENVIRONMENTAL CONDITIONS IN THE NORTHERN GREAT PLAINS

by

Laura Tindall Ouverson

Master of Science

Land Resources and Environmental Sciences

MONTANA STATE UNIVERSITY

Bozeman, Montana

July 12 2021

ABSTRACT

Soil bacterial communities are essential components of the soil ecosystem that support crop production and indicate a soil’s health. However, agriculture in semiarid drylands and their associated soil bacterial communities face increasingly warmer and drier conditions due to climate change. Two complementary studies were conducted to assess the response of soil bacterial communities to cropping systems, temporal changes, and soil temperature and moisture conditions in semiarid, dryland agricultural systems of the Northern Great Plains. 

The first study focused on soil bacterial community response to crop phase (i.e., crop species) of a rotation in contrasting cropping systems (chemical inputs and no-till, USDA-certified organic tilled, and USDA-certified organic sheep grazed) over a growing season. Organic grazed management supported more diverse bacterial communities than chemical no-till, though diversity in all systems decreased over the growing season. Organic grazed bacterial communities were distinct from those in the organic tilled and chemical no-till systems. An interaction between cropping system and crop phase affected community dissimilarity, indicating that overarching management systems and environmental conditions are influential on soil bacterial communities.

The second study evaluated soil bacterial communities in a winter wheat-cover crop or fallow rotation. Observations were conducted in the summer fallow and two cover crop mixtures differing by species composition and phenologies, terminated by three different methods (chemical, grazing, or haying), and subjected to either induced warmer/drier or ambient soil conditions. Only the presence and composition of cover crops affected bacterial community dissimilarity. Bacterial communities responded to an interaction between the presence and composition of cover crops and environmental conditions, but not termination. Additionally, soil bacterial communities from mid-season cover crops were distinct from early season and fallow. No treatments affected bacterial communities in 2019, which could be attributed to historic rainfall. Cover crop mixtures including species tolerant to warmer and drier conditions can foster diverse soil bacterial communities compared to fallow soils.

Overall, these studies increased our understanding of how soil bacterial communities respond to soil health building practices in the Northern Great Plains. Cropping systems can foster unique soil bacterial communities, but these effects may be moderated by environmental and temporal conditions.

Paper published on soil microbes, climate change, and agriculture!

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I’m pleased to announce that an article was published today on soil microbes, climate change, and agriculture! As local climates continue to shift, the dynamics of above- and below-ground associated bio-diversity will also shift, which will impact food production and the need for more sustainable practices. 

This publication is part of a series, from data collected from a long-term farming experiment in Bozeman, MT, led by researchers at Montana State University with whom I have published several times, including:

In this study, cropping system (such as organic or conventional), soil temperature, soil moisture, the diversity and biomass of weed communities, and treatment with Wheat streak mosaic virus were compared as related to the bacterial community in the soil associated with wheat plant roots.

This paper is open-access, which means anyone can read the full paper.

Dryland cropping systems, weed communities, and disease status modulate the effect of climate conditions on wheat soil bacterial communities.

Ishaq, S.L., Seipel, T., Yeoman, C.J., Menalled, F.D. 2020. mSphere DOI: 10.1128/mSphere.00340-20. Article.

Abstract

Little knowledge exists on how soil bacteria in agricultural settings are impacted by management practices and environmental conditions under current and predicted climate scenarios.  We assessed the impact of soil moisture, soil temperature, weed communities, and disease status on soil bacterial communities between three cropping systems: conventional no-till (CNT) utilizing synthetic pesticides and herbicides, 2) USDA-certified tilled organic (OT), and 3) USDA-certified organic with sheep grazing (OG).  Sampling date within the growing season, and associated soil temperature and moisture, exerted the greatest effect on bacterial communities, followed by cropping system, Wheat streak mosaic virus (WSMV) infection status, and weed community. Soil temperature was negatively correlated with bacterial richness and evenness, while soil moisture was positively correlated with bacterial richness and evenness.  Soil temperature and soil moisture independently altered soil bacterial community similarity between treatments.  Inoculation of wheat with WSMV altered the associated soil bacteria, and there were interactions between disease status and cropping system, sampling date, and climate conditions, indicating the effect of multiple stressors on bacterial communities in soil.  .  In May and July, cropping system altered the effect of climate change on the bacterial community composition in hotter, and hotter and drier conditions as compared to ambient conditions, in samples not treated with WSMV.  Overall, this study indicates that predicted climate modifications as well as biological stressors play a fundamental role in the impact of cropping systems on soil bacterial communities.

Menalled lab at MSU seeking graduate students

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The Menalled lab has MS and PhD opportunities in agroecology, “Diversifying cropping systems through cover crops and targeted grazing: impacts on plant-microbe-insect interactions, yield, and economic returns”.

Last year, I did a post-doc in Dr. Fabian Menalled’s weed ecology lab at MSU exploring the effect of farming system and climate change on bacteria in the wheat rhizosphere.  If you love friendly lab groups, early morning field work, and being outside, then working in the Menalled lab in Bozeman, Montana might be the place for you.

Kyla and I are attaching wheat to other wheat with paperclips.
Climate change simulators.
Menalled Lab breakfast at the Storm Castle Cafe.

Of course, in Montana, it helps if you also love winter…

A lovely view of the Spanish Peaks.
Deer Lake…so where do we start digging?