About

Professor Matt Ryan teaches the PLSCS 1900 class titled "Sustainable Agriculture" at Cornell University. In this course, students create short films about sustainable agriculture, choosing topics that interest them. Each year, more than fifty films are submitted by students, showcasing a variety of perspectives on sustainable agriculture. These films are featured and accessible through the e-commons repository. The page highlights the active engagement of students in exploring sustainable agriculture under Professor Ryan's guidance.

Research topics

• Ecology
• Biology
• Agronomy
• Business
• Agroforestry
• Environmental science
• Sociology
• Social Science
• Geography
• Agricultural science
• Economics
• Engineering
• Environmental resource management
• Marketing

Selected publications

• Selecting suitable predecessors: ecosystem services from cover crops to reduce tillage and fertilizer

  Scientific Reports · 2026-05-13

  articleOpen accessSenior author

  Ecosystem services from cover crops can reduce reliance on external inputs and intensive management practices; however, these benefits depend on crop sequence compatibility. The effect of cover crop selection on weed suppression and crop yield was tested by no-till planting winter and summer cash crops into different cover crops that were terminated and used as mulches. Management treatments involving supplemental weeding and fertilizer were also applied to summer cash crops. Overall, this research evaluated 80 combinations of cover crops, cash crops, and management treatments across four site-years in a total of 1280 experimental units. In the absence of supplemental management, cash crops exhibited a 2.6-fold mean difference in weed biomass and a 7.3-fold mean difference in yield when no-till planted into the best- versus worst-performing cover crops, indicating that cover crop selection impacted ecosystem services. Insights from this research can guide cover crop selection and facilitate ecological intensification of agriculture.

  PublisherOA PDFDOI

• Cereal rye ( <scp> <i>Secale cereale</i> </scp> ) and canola ( <scp> <i>Brassica napus</i> </scp> ) cover crops reduce dry bean ( <scp> <i>Phaseolus vulgaris</i> </scp> ) herbivore damage

  Pest Management Science · 2026-04-18

  article

  BACKGROUND: Cover crops can support soil health and increase habitats for beneficial insects in diverse cropping systems. The aim of this study was to evaluate the impact of cover crop-conditioned soil on plant defense responses and insect pest damage using dry bean (Phaseolus vulgaris L.) as a model. RESULTS: In a 2-year, multi-location field experiment comparing four cover crop treatments and a tilled control, we found that dry beans no-till planted into mechanically terminated cereal rye (Secale cereale L.) and canola (Brassica napus L.) experienced less insect damage than controls. In the laboratory, microbiome extracts from canola-enriched field soil increased dry bean jasmonic acid levels and reduced cowpea aphid (Aphis craccivora Koch) survival compared with other soil microbiome extracts. No differences in defense hormones were detected for dry bean grown in cereal rye soil microbiome extracts, however aphid survival was reduced on these plants compared to the controls. CONCLUSIONS: Cereal rye and canola cover crops reduced insect damage in dry bean fields. Soil microbiomes associated with canola enhanced defense-related compounds in dry bean, suggesting a potential mechanism for pest suppression in the field. However, the impacts of canola varied across microbiome sources, highlighting the need for additional studies. © 2026 Society of Chemical Industry.

  PublisherDOI

• Grain of the Future: Consumer Demand for Bread Made of Sustainable Perennial Grain Intermediate Wheatgrass

  Agricultural Economics · 2026-02-16

  articleOpen access

  ABSTRACT Intermediate wheatgrass (IWG), also known as Kernza, is a perennial grain crop with recognized environmental benefits, including improved water quality, increased soil carbon storage, and enhanced biodiversity. However, despite these advantages, consumer demand for IWG‐based products remains poorly understood, limiting its market potential. This study employs sensory analysis and an experimental BDM mechanism to estimate consumer willingness to pay (WTP) for IWG bread and assess the influence of sustainability information on purchasing decisions. Results suggest that IWG bread commands a price premium when accompanied by effective consumer education, with WTP estimates indicating a potential market niche for sustainability‐labeled perennial grains. Economic implications suggest that targeted consumer awareness campaigns, standardized eco‐labeling, and financial incentives could enhance adoption and market penetration. These findings offer insights for policymakers, agribusinesses, and sustainability advocates aiming to align consumer‐driven demand with environmental goals.

  PublisherOA PDFDOI

• Effects of soil tillage and nutrient management on weed abundance during the transition to organic grain production

  Weed Science · 2026-01-01

  articleOpen accessSenior authorCorresponding

  Abstract Effective weed management is critical to the long-term productivity of organic grain cropping systems. The Cornell Organic Cropping Systems Experiment was initiated in 2005 at the Musgrave Research Farm in Aurora, NY, to compare four organic cropping systems that differed primarily in intensity of mechanical weed management and soil nutrient inputs. A 3-yr rotation of corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and spelt (Triticum spelta L.)/red clover (Trifolium pratense L.) was grown in all systems. The four systems were characterized by High Fertility (red clover green manure, composted poultry manure, and commercial organic fertilizer to reach recommended fertility levels), Low Fertility (no fertility inputs other than the red clover and starter fertilizer for corn), Enhanced Weed Management (fertility management as in Low Fertility with additional tillage and cultivation and a higher spelt seeding density), and Reduced Tillage (primarily ridge tillage with different green manure crops). The experiment included two crop rotation entry points, enabling two of the three crops in the rotation to be grown every year. Results from the first two rotation cycles show that, in most cases, weed abundance and diversity increased during the transition to organic production, especially in the Reduced Tillage system. Perennial weeds increased in corn and soybean in the Reduced Tillage system in the second rotation cycle, which contributed to its poor performance relative to the three other systems. Our results suggest that increased soil disturbance, including tillage and cultivation in corn and soybean, plays an important role in reducing weed populations, whereas high fertility levels may exacerbate weed problems. These findings underscore the importance of balancing weed and nutrient management in enabling sustainable organic grain crop production.

  PublisherOA PDFDOI

• Organic dry bean cultivar evaluation in the Northeast and Upper US Midwest: Opportunities for growers and food systems

  Agronomy Journal · 2025-09-01

  articleOpen access

  Abstract Organic dry bean [ Phaseolus vulgaris (L.)] production presents an opportunity for expanding diversified farming in the Northeast and Upper US Midwest. Cultivar trials were conducted in 2023 and 2024 in New York, Vermont, Wisconsin, and Maine evaluating 32 cultivars across black, navy, pinto, small red, and specialty market classes. Trials assessed yield, pod height, and uprightness under certified organic management. Surveys evaluated consumer preferences for taste, texture, appearance of beans, and willingness to pay for organically produced beans across marketplaces. Modern commercially available market classes outperformed specialty cultivars in yield, with average yields of 3840 ± 113 kg ha −1 for pinto beans, 3730 ± 80.7 kg ha −1 for black beans, 3560 ± 94.8 kg ha −1 for navy beans, 3470 ± 122 kg ha −1 for small red beans, and 2660 ± 64.4 kg ha −1 for specialty beans; navy and black market classes scored higher in uprightness than pinto, small red, and specialty market classes in seven of eight site‐years. Greater variability was observed at the cultivar level for yield, uprightness, and pod height. Survey results revealed preferences for specialty cultivars based on flavor and seed coat appearance, with respondents willing to pay up to $11.00 per pound for organic dry beans in direct markets. Breeding and developing optimized management strategies for organic specialty dry bean production could improve production and allow growers to access high‐value markets, including direct‐to‐consumer sales, in the Northeast and Upper US Midwest.

  PublisherOA PDFDOI

• Not as hard as it seems? Labor challenges and opportunities for agroecological practices in the United States

  Agriculture and Human Values · 2025-10-24 · 1 citations

  articleSenior author
  PublisherDOI

• Hairy vetch ( <i>Vicia villosa</i> Roth) germplasm contains a cryptic second species ( <i>Vicia varia</i> Host)

  Crop Science · 2025-01-01 · 1 citations

  article

  Abstract Hairy vetch is a promising legume cover crop ( Vicia villosa Roth) for the northern United States. Based on evidence from molecular markers, multi‐site evaluations, and morphological observations, a distinct second species exists within US hairy vetch germplasm, referred to hereafter as smooth vetch ( Vicia varia Host). Morphologically, hairy vetch is highly variable, but this study found statistically significant differences between smooth and hairy vetch in visual pubescence scores, plant maturity, and calyx lobe lengths. We used a panel of single sequence repeat (SSR) markers to assign cultivars and breeding materials to the two species and found that many commercial cultivars are smooth vetch. Interestingly, the SSR panel indicated that woollypod vetch ( Vicia dasycarpa Ten.) is a subpopulation of hairy vetch. Based on an elastic net model trained with multi‐site trial results from &gt;35 site‐years, smooth vetch is not winter hardy in the northern United States but has superior performance relative to hairy vetch in the south‐central and Pacific Northwest United States. Specifically, smooth vetch has greater performance in environments with mild winters, cool spring temperatures, or low clay soils. Because of these differences in adaptation, differentiating these species will greatly improve agronomic outcomes and accelerate ongoing cover crop breeding progress.

  PublisherDOI

• Rolled‐crimped cover crops for organic no‐till planted winter wheat (<i>Triticum aestivum</i>) in the Northeast region of the United States

  Agrosystems Geosciences & Environment · 2024-12-01

  articleOpen access1st authorCorresponding

  Abstract Mulch from cover crops can suppress weeds and facilitate organic no‐till corn and soybean production. However, research is lacking on the no‐till planting small grain crops into rolled‐crimped cover crops. An experiment was conducted to test the effects of no‐till planting winter wheat ( Triticum aestivum L.) into five cover crops planted in early summer, mid‐summer, and late summer. Cover crops were terminated with a roller‐crimper, and winter wheat was simultaneously no‐till planted in early fall. A “no cover crop” control treatment was also included, where wheat was planted into tilled soil. Cover crop and weed biomass at wheat planting varied by cover crop planting date and species. Early‐summer‐planted sorghum sudangrass [ Sorghum bicolor (L.) Moench × S. sudanense (Piper) Stapf.] produced the most cover crop biomass and had among the lowest weed biomass at wheat planting and wheat harvest. However, wheat seedling density and grain yield were relatively low in the early‐planted sorghum sudangrass treatment compared with the other cover crop treatments, indicating a tradeoff between weed suppression and wheat yield. Early‐planted buckwheat ( Fagopyrum esculentum Moench) and early‐planted soybean [ Glycine max (L.) Merr.] had among the highest wheat grain yields, but no treatments yielded more than the “no cover crop” control. Wheat grain nitrogen was variable and may have been impacted by multiple factors, including wheat density. Results from this experiment indicate that rolled‐crimped cover crops can facilitate organic no‐till winter wheat production, but more research is needed to overcome tradeoffs and optimize production.

  PublisherOA PDFDOI

• Legacy effects of crop diversity on weed-crop competition in maize production

  npj Sustainable Agriculture · 2024-12-18 · 1 citations

  articleOpen accessSenior author

  Abstract The legacy effects of crop diversity on maize ( Zea mays L.) tissue nutrient composition, weed community structure, and intensity of weed-crop competition were assessed through a field experiment at two sites in the northeastern United States. Fields were conditioned with crop diversity gradients from summer 2016 to spring 2019. The crop diversity gradients ranged from a single cultivar to sixteen intercropped cultivars (four species, four cultivars per species) and were established in organic annual and perennial cropping systems. Following the three-year conditioning phase, maize was planted across the entire experiment, and each conditioning-phase diversity treatment was split into weed-free, ambient-weed, moderate-weed, and heavy-weed treatments. Within each cropping system, the effect of crop diversity legacy on weed-crop competition was negligible. In contrast, weed-crop competition varied between the maize grown in soil conditioned by the annual and perennial cropping systems.

  PublisherOA PDFDOI

• Fertility and tillage intensity affect weed community diversity and functional structure in long‐term organic systems

  Ecological Applications · 2024 · 3 citations

  Senior authorCorresponding
  • Agronomy
  • Biology
  • Environmental science

  Abstract Knowledge of how agricultural management interacts with weed seed banks and emergent weed communities is crucial for proactive weed management. Though studies have detailed how differences in disturbance and nutrient applications between organic and conventional herbicide‐based systems affect weed communities, few have focused on these same factors in contrasting organic systems. This study assessed the seed banks and emergent weed communities from the most recent crop rotation cycle (2017–2022) of a long‐term experiment, which compared four organic grain and forage cropping systems differing in nutrient inputs and soil disturbance. The high fertility (HF) system received high‐rate nutrient applications, low fertility (LF) received low‐rate applications, enhanced weed management (EWM) focused on weed control through frequent soil disturbance, and reduced tillage (RT) prioritized soil health with less intense or frequent soil disturbance. Soil samples for greenhouse germination assays were collected at the beginning (2017) and end (2022) of the rotation to explore how these four systems influenced seed bank dynamics over time. Weed community biomass was also sampled in each crop during this time. Treatment effects on weed abundance, taxonomic diversity, and community‐weighted means and functional dispersion of weed traits were analyzed with generalized mixed‐effect models. The RT system had the highest weed seed bank taxonomic diversity, and EWM had the lowest. RT and LF had higher functional dispersion of traits than HF in the seed bank. Weed seed bank communities in HF and RT were characterized by short, small‐seeded, and early germinating weed species. However, seed banks were also labile: Differences between systems in seed density and all other mean trait values were dependent on the crop, which preceded seed bank sampling. Likewise, differences among emergent weed communities in the four systems depended on an interaction between crop species and their planting year. Results suggest that resource availability and intensity of disturbance act as weed community assembly filters in organic cropping systems. Organic growers seeking to design systems that balance weed management and production goals can use relatively low soil disturbance and nutrient application to increase weed community taxonomic or functional diversity without necessarily increasing weed biomass or seed bank density.

  PublisherOA PDFDOI

Frequent coauthors

• Stéphane Cordeau

  Agroécologie

  66 shared

• Steven B. Mirsky

  47 shared

• Antonio DiTommaso

  Cornell University

  41 shared

• Richard G. Smith

  University of New Hampshire

  32 shared

• Sandra Wayman

  Cornell University

  26 shared

• William S. Curran

  Pennsylvania State University

  25 shared

• Laurie E. Drinkwater

  New York State College of Agriculture & Life Sciences

  21 shared

• Brian Caldwell

  Cornell University

  20 shared

Labs

• Sustainable Cropping Systems LabPI