Turfgrass Epistemology

Do wetting agents always help water move into soil? We revisit the classic 1962 study The Effect of Wetting Agents on Infiltration by R. E. Pelishek, J. Osborn, and J. Letey, which found that wetting agents improved infiltration in hydrophobic soils but could have little or even adverse effects in soils that were not strongly water repellent.

#WettingAgents #Turfgrass #SoilScience #WaterRepellency #GolfCourseManagement #TurfScience #Agronomy

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In Part 2 of my Turfgrass Q&A series, I answer more of your YouTube comments and emails on topics including soil testing, heat stress, nitrogen management, and other common turfgrass questions. Every answer is backed by peer-reviewed research to help separate fact from fiction and improve your turf management decisions.

#Turfgrass #LawnCare #GolfCourseManagement #SoilScience #Nitrogen #Agronomy #TurfScience #GolfSuperintendent #LawnTips #QandA #Grass #Science

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Have questions about urea fertilizer, coated nitrogen, university research, or real-world turf management? In this first Q&A episode, I respond to your YouTube comments and emails using peer-reviewed turfgrass research to separate evidence from opinion and help you make better management decisions.

#Turfgrass #LawnCare #GolfCourseManagement #Nitrogen #Urea #Fertilizer #Agronomy #TurfScience #SoilScience #GolfSuperintendent #LawnTips #QandA

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Is it really time to stop using urea fertilizer? In this Tinfoil Turfgrass, I review the claims made in a popular YouTube video and compare them with peer-reviewed turfgrass research to separate evidence from misinformation. Discover what the science actually says about urea, nitrogen fertilizers, volatilization, and best management practices for healthy turf.

#Urea #LawnCare #Turfgrass #Nitrogen #Fertilizer #GolfCourseManagement #TurfScience #FactCheck #Agronomy #lawncaretips 

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Can water really become "wetter"? In this video, we explore the classic paper Soil Wetting Agents by Robert A. Moore (1959) and explain how wetting agents improve water infiltration, root development, and turfgrass performance. Discover why this pioneering research still influences modern turf management today.

Paper: Soil Wetting Agents
Author: Robert A. Moore
Year: 1959

#Turfgrass #WettingAgents #SoilScience #GolfCourseManagement #Agronomy #TurfManagement #GolfCourse #WaterManagement #TurfgrassScience

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Can wetting agents improve water movement in golf course turf? In this video, we explore the classic paper "Turfgrass Improvement with a New Water" by Robert A. Moore (1957) and examine how wetting agents help water penetrate the soil, reduce localized dry spots, and promote healthier turfgrass. Discover why this pioneering research continues to influence modern golf course management and turfgrass science.

Paper: Turfgrass Improvement with a New Water
Author: Robert A. Moore
Year: 1957

#Turfgrass #GolfCourseManagement #WettingAgents #SoilScience #GolfSuperintendent #USGA #Agronomy #TurfManagement #GolfCourse #TurfgrassScience

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Did your brain make your decision before you became aware of it? In this video, we explore the groundbreaking neuroscience study that found brain activity can predict a person's choice seconds before conscious awareness, and what it means for free will.

Paper: Unconscious Determinants of Free Decisions in the Human Brain (2008)
Authors: Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze, and John-Dylan Haynes

#FreeWill #Neuroscience #BrainScience #DecisionMaking #Psychology #CognitiveScience #science 

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Did Benjamin Libet's famous 1983 experiment prove that your brain decides before you do? In this episode, we examine Libet, Gleason, Wright, & Pearl (1983), "Time of Conscious Intention to Act in Relation to Onset of Cerebral Activity (Readiness-Potential): The Unconscious Initiation of a Freely Voluntary Act." We'll explain the readiness potential, what the study actually found, common misconceptions, and what it does—and does not—tell us about free will, consciousness, and human decision-making.

#Libet #FreeWill #Neuroscience #Psychology #Consciousness #ReadinessPotential #Science #CriticalThinking #BrainScience #TurfgrassEpistemology

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In this episode of Turfgrass Epistemology, we examine Stanley Milgram's classic paper, Behavioral Study of Obedience (1963), and explore how authority influences our beliefs and decisions. Why do turf managers, consultants, and consumers often accept claims because a professor, university, or industry expert said them? Learn how the logical fallacy of Appeal to Authority can lead us to substitute credentials for evidence—and why scientific claims should be evaluated by data, not status.

Paper Discussed:
Milgram, S. (1963). Behavioral Study of Obedience. Journal of Abnormal and Social Psychology, 67, 371–378.

#AppealToAuthority #StanleyMilgram #CriticalThinking #LogicalFallacies #TurfgrassEpistemology #Science #EvidenceBasedManagement #GolfCourseManagement #Agro...

In this episode of Turfgrass Epistemology, we examine one of the most influential scientific papers ever published: Judgment Under Uncertainty: Heuristics and Biases by Amos Tversky and Daniel Kahneman (1974).

This landmark article introduced the concepts of representativeness, availability heuristics, and anchoring—mental shortcuts that help us make decisions but can also lead to systematic errors in judgment. These cognitive biases help explain why anecdotes, testimonials, and memorable success stories often outweigh scientific evidence in turfgrass management, agriculture, business, and everyday life.

Why do people conclude that a fertilizer, biostimulant, wetting agent, or soil amendment works af...

Why do smart people search for evidence that confirms their beliefs instead of trying to prove themselves wrong? In this video, we explore Peter Wason's famous 2-4-6 experiment and the origins of confirmation bias.

Paper: On the Failure to Eliminate Hypotheses in a Conceptual Task (1960)
Author: P. C. Wason

#ConfirmationBias #CriticalThinking #Psychology #DecisionMaking #ScientificThinking #Wason246 #BehavioralScience 

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Why do generic soil reports feel surprisingly accurate? In this video, we explore the Forer Effect and discuss how vague, universally true statements can create the illusion of personalized insight—whether in personality tests, astrology, or soil analysis.

Paper: The Fallacy of Personal Validation: A Classroom Demonstration of Gullibility (1949)
Author: Bertram R. Forer

#ForerEffect #BarnumEffect #Psychology #CriticalThinking #SoilScience #Turfgrass #ScienceCommunication

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Why do people conform to group pressure even when they know the group is wrong? In this video, we explore Solomon Asch's landmark conformity study, Opinions and Social Pressure (1955), and reveal what his famous experiments teach us about social influence, peer pressure, independent thinking, and human psychology.

Paper: Opinions and Social Pressure (1955)
Author: Solomon E. Asch

#Psychology #Conformity #AschExperiment #SocialPsychology #PeerPressure #BehavioralScience

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Does summer nitrogen really make brown patch worse in tall fescue? In this interview, Dr. Jada Powlen discusses her 2024 study and explains why cultivar selection may be more important than nitrogen rate for managing brown patch disease.

Paper: Brown patch severity of five tall fescue cultivars as influenced by summer nitrogen rates (2024)
Authors: Jada S. Powlen, James P. Kerns, Michael A. Fidanza, and Cale A. Bigelow

#BrownPatch #TallFescue #Turfgrass #Nitrogen #LawnCare #TurfScience #PlantPathology

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In this video, I break down the classic study “Optimizing Manganese Fertilization for the Suppression of Take-All Patch Disease on Creeping Bentgrass.” We examine whether manganese applications can suppress take-all patch, how application timing influences disease control, and why soil chemistry matters.

The results showed that manganese fertilization significantly reduced take-all patch severity, especially when soil manganese availability was low.

If you're interested in take-all patch management, manganese fertility, creeping bentgrass, and evidence-based turfgrass science, this is a must-watch discussion.

#turfgrass #takeallpatch #manganese #soilscience #bentgrass #golfcoursemanagement #turfgrassscience 

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In this video, I break down the study “Evaluation of Calcium Silicate for Brown Patch and Dollar Spot Suppression on Turfgrasses.” We examine whether calcium silicate (Si fertilizers) actually suppress turfgrass diseases like brown patch and dollar spot.

The results show that calcium silicate did not reduce dollar spot and, in some cases, actually increased brown patch severity, likely due to nutrient imbalances rather than any true disease suppression effect.

If you're interested in silicon fertilizers, disease control, and evidence-based turfgrass management, this is a must-watch breakdown.

#turfgrass #dollarspot #brownpatch #soilscience #fertilizer #turfgrassscience #golf...

In this video, I break down the research on biological and oil-based fungicides for dollar spot control in turfgrass. We examine whether products like biological fungicides, mineral oils, and plant-based treatments actually work compared to traditional chemistry.

The results show that most biological products failed to provide consistent, season-long dollar spot control, while some oil-based products offered limited suppression under lower disease pressure.

If you're interested in dollar spot management, fungicide alternatives, and evidence-based turfgrass science, this video is for you.

#turfgrass #dollarspot #fungicide #soilscience #golfcoursemanagement #lawncare #turfgrassscience 

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In this video, I break down a lawn care discussion on nitrogen fertilizers and turfgrass performance, separating what’s scientifically sound from what may be oversimplified.

We take a closer look at how nitrogen source, timing, and application strategy actually influence turfgrass growth—and whether the claims being made hold up under turfgrass science and soil fertility principles.

If you're trying to better understand lawn fertilizers, nitrogen management, and turfgrass health, this video will help you make more informed, evidence-based decisions.

#turfgrass #lawncare #fertilizer #nitrogen #soilscience #turfgrassepistemology #lawntips
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In this video, I break down the “DirtBooster Organic Lawn and Garden Treatment” video from How to With Doc and take a closer look at the claims around soil microbes, biochar, humic substances, and “super compost.”

The product is promoted as a way to rapidly build soil biology using ingredients like biochar, molasses, and microbial additives, but does the science support the idea that this translates into better turfgrass performance?

We evaluate the logic, the mechanisms being implied, and whether these types of organic amendments actually deliver measurable benefits in turfgrass systems, lawn care, and soil man...

In this video, I break down a popular lawn care video on soil testing, pH, and nutrient recommendations and separate what’s useful from what may be misleading.

We take a closer look at how soil test results are interpreted, whether the recommendations actually make sense, and how to approach fertility decisions using evidence-based turfgrass science.

If you're trying to better understand soil tests, lawn care recommendations, pH adjustment, and fertilizer decisions, this discussion will help you think more critically about what to trust—and why.

#turfgrass #soiltesting #lawncare #fertilizer #soilscience #turfgrassepistemology #lawntips
...

In this video, I break down a lawn care video making the rounds online and separate what sounds right from what’s actually supported by turfgrass science. We take a closer look at the claims, the reasoning behind them, and whether they hold up when you apply basic principles of soil science and plant physiology.

If you're trying to cut through the noise in lawn care advice, turfgrass management, and fertilizer recommendations, this episode will help you think more critically about what you’re hearing—and why it matters.

#turfgrass #lawncare #soilscience #fertilizer #turfgrassepistemology #lawntips #golfco...

In this video, I respond to comments and emails and answer a common question: Why do dog urine (pet) spots last so long in turfgrass? We break down the science behind nitrogen burn, salt injury, and recovery limitations in lawns.

If you’ve ever struggled with dog spots, lawn damage, or uneven turf recovery, this episode will help you understand what’s really happening—and what actually works.

#turfgrass #lawncare #dogspots #soilscience #fertilizer #lawntips #turfgrassepistemology

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In this episode, I sit down with Rob from Turf Therapy and Cam from Elevated Lawnscapes to talk all things lawn care, content creation, and turfgrass management. We discuss their approach to building great lawns, lessons learned on YouTube, and how they balance real-world lawn care with online advice.

This is a great conversation for anyone interested in DIY lawn care, turfgrass tips, and the growing lawn care YouTube community.

#turfgrass #lawncare #lawnyoutube #turftherapy #elevatedlawnscapes #DIYlawn #golfcoursemanagement 

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In this video, I break down the study “Influence of Calcium and Nitrogen Fertilizer on Creeping Bentgrass Infected with Dollar Spot.” We examine whether  it is calcium or lime that actually suppresses dollar spot, how it compares to nitrogen, and what happens when the two are applied together.

The results show that both calcium and nitrogen reduced disease individually, but combining them was less effective due to antagonism, with calcium also improving root growth and stress tolerance rather than directly controlling disease. Unfortunately, the authors do not discuss the influence of lime rather than the calcium. This mista...

In this video, I break down the classic study “Microbial Populations and Suppression of Dollar Spot Disease in Creeping Bentgrass with Inorganic and Organic Amendments.” We take a close look at whether organic fertilizers actually suppress dollar spot and how they influence microbial populations in turfgrass systems.

The results show that while some organic amendments increased microbial activity, dollar spot suppression was inconsistent and often less effective than fungicides, with nitrogen and growth response playing a major role.

If you’re interested in dollar spot control, soil microbes, organic vs synthetic fertilizers, and turfgrass disease manage...

In this episode, I interview Dr. Scott McElroy (Auburn University) about weed control in turfgrass, including best practices for herbicide timing, resistance management, and how herbicides interact with insecticides. We also discuss common mistakes, application strategies, and where to find reliable, evidence-based recommendations.

If you manage turf, this conversation will help you improve your weed identification, herbicide programs, and integrated pest management (IPM) decisions.

#turfgrass #weedcontrol #herbicides #IPM #golfcoursemanagement #turfgrassscience #agronomy 

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In this video, I break down a Floratine Masterclass where Tim Cartwright discusses a common claim about calcium availability in soils. I examine the argument, the science behind calcium in turfgrass soils, and whether the explanation actually aligns with what we know from soil chemistry and turfgrass research.

If you manage turfgrass or are interested in soil testing, calcium availability, base saturation, and turfgrass fertility myths, this discussion will help you think critically about the claims often made in the industry.

#turfgrass #soilscience #calcium #soiltesting #turfmanagement #golfcoursemanagement #turfgrassepistemology 

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In this video, I break down the research article “Soil Amendments and Fertilizer Source Effects on Creeping Bentgrass Establishment, Soil Microbial Activity, Thatch, and Disease.” We examine whether organic fertilizers, poultry meal, and humate soil amendments really improve bentgrass establishment, microbial activity, disease suppression, and thatch management on sand-based greens.

The results show that readily available nitrogen from synthetic fertilizers produced faster establishment and generally better turf quality, while organic programs increased microbial activity but did not improve establishment or consistently suppress disease.

If you manage golf greens, creeping bentgrass, or sand-based rootzones, this study prov...

In this video, I review the classic turfgrass study “Dollar Spot Severity, Tissue Nitrogen, and Soil Microbial Activity in Bentgrass as Influenced by Nitrogen Source.” We take a close look at whether organic fertilizers really suppress dollar spot and whether soil microbial activity plays the role many people claim.

The results may surprise you. The study found that disease suppression was more closely related to nitrogen availability and turf growth than to microbial activity or organic fertilizer sources. 

If you manage bentgrass fairways or want evidence-based guidance on dollar spot management, nitrogen fertilization, and organic vs sy...

In this video, I review the research article “Strategies for Increasing Ferrous Sulfate Efficacy Against Dollar Spot of Creeping Bentgrass.” We examine how ferrous sulfate (FeSO₄) can suppress dollar spot, how application techniques affect performance, and whether combining it with chlorothalonil improves disease control.

The study found that nozzle selection and application strategy influence performance, and that ferrous sulfate can reduce the amount of chlorothalonil needed and extend its effectiveness against dollar spot. 

If you manage creeping bentgrass greens or fairways, this research provides valuable insights into dollar spot management, iron applications, and fungicide optimization.

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In this episode of Turfgrass Epistemology, I critically examine the article “Exploratory Study on the Foliar Incorporation and Stability of Isotopically Labeled Amino Acids Applied to Turfgrass” (Agronomy, 2020) and use it as a case study in how “science” can be used to persuade without truly informing.

On the surface, this paper uses isotopic labeling to show that foliar-applied glutamate can be absorbed and incorporated into creeping bentgrass metabolism. But in this video, I explain why the study’s publication in a predatory journal, its direct funding and involvement by one of the product’s commercial stakeholders, and its failure...

In this episode of Turfgrass Epistemology, I break down the peer-reviewed Crop Science article “Mowing Strategies and Dew Removal to Minimize Dollar Spot on Creeping Bentgrass” by Ellram, Horgan, and Hulke (2007).

This study evaluates how mowing time, dew removal frequency, blade sharpness, and leaf wetness duration (LWD) influence dollar spot severity on creeping bentgrass fairways. I explain why mowing at 4:00 AM consistently reduced dollar spot compared to 10:00 AM, why daily dew removal outperformed alternate-day removal, and why dull mower blades did not increase disease despite common belief. The controlled-environment data also show lesion size increased dramatically as leaf...

In this episode of Turfgrass Epistemology, I discuss the Purdue Extension publication “Common Diseases on Cool-Season Lawns” (BP-218-W), a practical guide to identifying and managing diseases on Kentucky bluegrass and tall fescue.

This publication outlines major lawn diseases including dollar spot, brown patch, Pythium blight, red thread, rust, summer patch, gray leaf spot, and leaf spot/melting out, while also emphasizing the critical distinction between biotic diseases and abiotic disorders such as compaction, drought, and nutrient stress. I explain why accurate diagnosis requires understanding host species, environmental conditions, and disease spread patterns—not just visual symptoms.

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In this episode of Turfgrass Epistemology, I discuss the peer-reviewed article “Dollar Spot Resistance among Blends of Creeping Bentgrass Cultivars” by Abernathy et al. (2001), published in Crop Science.

This study evaluates whether blending creeping bentgrass cultivars can reduce dollar spot severity compared to monostands on golf course putting greens. I explain how highly susceptible cultivars like Crenshaw increased disease pressure in blends, how resistant cultivars like L-93 suppressed dollar spot, and why overall disease levels in blends often reflected a compromise between the resistance levels of the individual components.

The key takeaway: blending resistant and susc...

In this episode of Turfgrass Epistemology, I break down the classic Crop Science paper “Assessing Irrigation Management for Its Effects on Disease and Weed Levels in Perennial Ryegrass” by Jiang, Fry, and Tisserat (1998).

This study directly examines how irrigation scheduling (daily vs. ET-based irrigation) influences brown patch, dollar spot, weed pressure, pesticide use, and turf quality on perennial ryegrass fairways. I explain how ET-based irrigation reduced water use by nearly 200%, how daily irrigation suppressed brown patch but increased dollar spot, and why irrigation strategy did not significantly influence crabgrass or dandelion populations.

If you manage golf...

In this episode of Turfgrass Epistemology – Comments & Emails Part 2, I continue responding to viewer questions and email discussions about turfgrass management, soil testing, fertilizer programs, dollar spot control, and common lawn care myths.

This follow-up video addresses new comments from golf course superintendents, lawn care operators, and homeowners who are trying to separate evidence-based turfgrass science from marketing claims and social media advice. I clarify misunderstandings about nutrient ratios, iron applications, nitrogen programs, and disease suppression while explaining how to interpret research correctly.

If you’re interested in soil fertility, turfgrass disease management, golf course agro...

In this episode of Turfgrass Epistemology, I respond to viewer comments and emails covering some of the most common questions and misconceptions I see about turfgrass science, soil fertility, nutrient management, and disease control.

I address recurring themes from golf course superintendents, lawn care professionals, and homeowners, explain where confusion often arises, and clarify how peer-reviewed research should be interpreted instead of relying on anecdotes, marketing claims, or social media shortcuts.

This video focuses on critical thinking in turfgrass management, explaining how to evaluate advice, understand soil and tissue test results, and avoid common reasoning...

In this episode of Turfgrass Epistemology, I discuss the peer-reviewed article “Dollar Spot and Gray Leaf Spot Severity as Influenced by Irrigation, Chlorothalonil, Paclobutrazol, and a Wetting Agent” by McDonald, Dernoeden, and Bigelow (2006), published in Crop Science.

This landmark study examines how irrigation regime, soil moisture, and common management inputs influence dollar spot and gray leaf spot development on creeping bentgrass and perennial ryegrass fairways. I explain why dollar spot was consistently more severe under dry, infrequently irrigated conditions, how soil moisture strongly influenced disease severity late in the season, and what this means for cultural disease mana...

In this episode of Turfgrass Epistemology, I discuss and interpret the peer-reviewed article “Optimizing Liquid-Applied Iron Sulfate Rate and Application Interval for Dollar Spot Suppression on Golf Course Fairways” by Soldat et al. (2024), published in Crop Science.

This paper builds on earlier iron sulfate research and focuses on practical optimization—how rate, application interval, and spray volume influence dollar spot suppression on creeping bentgrass and annual bluegrass fairways. I explain the dose-dependent response observed across multiple locations, why 7-day reapplication intervals consistently outperformed 14-day intervals, and why spray water volume and tank-mixing with fertilizer had minimal impact on dis...

In this episode of Turfgrass Epistemology, I discuss and interpret the peer-reviewed article “Influence of Ferrous Sulfate and Its Elemental Components on Dollar Spot Suppression” by McCall et al. (2016), published in Crop Science. This paper is foundational to many modern discussions about using iron—specifically ferrous sulfate—as a tool for managing dollar spot on creeping bentgrass putting greens.

The study evaluates whether ferrous sulfate itself, or its individual components iron and sulfur, are responsible for observed dollar spot suppression. Using both field trials on USGA-spec creeping bentgrass greens and controlled in-vitro assays, the authors show that ferrous...