Numbered Publications: Plant and Soil Sciences
ID-199: Prechilling Switchgrass Seed on Farm to Break Dormancy
Holly Boyd, Cindy Finneseth, Tom Keene, Laura Schwer, Ray Smith | Mar. 13, 2023 (Revised)
Switchgrass (Panicum virgatum L.) is a warm-season, perennial bunch-type grass native to the North American Tallgrass Prairie. It has been investigated as a renewable energy crop due to its high productivity across a wide geographic range including various environmental conditions and soil types. Switchgrass has also been used for erosion control, summer grazing in pasture and hay systems for cattle, native prairie restoration, wildlife habitat, fiber production, and as an ornamental grass.
AGR-16: Taking Soil Test Samples
Lloyd Murdock, Greg Schwab, Frank Sikora, Bill Thom | Mar. 13, 2023 (Revised)
The most important part of making fertilizer recommendations is collecting a good, representative soil sample. Soil test results and fertilizer recommendations are based solely on the few ounces of soil submitted to the laboratory for analysis. These few ounces can represent several million pounds of soil in the field. If this sample does not reflect actual soil conditions, the results can be misleading and lead to costly over- or under-fertilization. It is necessary to make sure that the soil sample sent to the laboratory accurately represents the area sampled.
ID-163: Agricultural Lime Recommendations Based on Lime Quality
David Ditsch, Josh McGrath, Lloyd Murdock, Edwin Ritchey, Frank Sikora | Mar. 13, 2023 (Revised)
Soil acidity is one of the most important soil factors affecting crop growth and ultimately, yield and profitability. It is determined by measuring the soil pH, which is a measure of the amount of hydrogen ions in the soil solution. As soil acidity increases, the soil pH decreases. Soils tend to be naturally acidic in areas where rainfall is sufficient to cause substantial leaching of basic ions (such as calcium and magnesium), which are replaced by hydrogen ions. Most soils in Kentucky are naturally acidic because of our abundant rainfall.
AGR-271: Frost Seeding Clover: A Recipe for Success
Jimmy Henning, Ray Smith, Chris Teutsch | Mar. 2, 2023 (New)
Legumes are an essential part of a strong and healthy grassland ecosystems. They form a symbiotic relationship with Rhizobium bacteria in which the bacteria fix nitrogen from the air into a plant-available form and share it with the legume. Clover also increases forage quality and quantity and helps to manage tall fescue toxicosis. In the past, the positive impact of clover on tall fescue toxicosis has always been thought to simply be a dilution effect, but new research from the USDA's Forage Animal Production Unit in Lexington shows that compounds found in red clover can reverse vasoconstriction that is caused by the ergot alkaloids in toxic tall fescue. The primary compound found in red clover is a vasodilator called "Biochanin A."
AGR-272: Preemergence Herbicides for Kentucky Lawns
Kenneth Clayton, Jason Vaughn, Beth Wilson | Feb. 16, 2023 (New)
Herbicides are used to control unwanted plants in many different locations. Postemergence herbicides are sprayed on actively growing weeds. In turfgrass, several herbicides are used to control weeds before they germinate and begin to grow. These are called "preemergence herbicides" and are commonly sold as "weed preventers." They control germinating weed seeds and subsequent growth. Therefore, to be effective, preemergence herbicides must be present in the upper soil surface before weed seeds germinate.
ID-160: Burley and Dark Tobacco Production Guide, 2023-2024
Andy Bailey, Ric Bessin, Lowell Bush, Ann Fisher, J.D. Green, Bill Pearce, Edwin Ritchey, Wayne Sanderson, Will Snell | Jan. 17, 2023 (Major Revision)
The 2022 season will be remembered as a year of extremes in weather patterns. Early in the field season, 2022 brought extreme drought and heat during transplanting in May and June followed by excessive rainfall in July in some areas. These conditions led to growers making significant replanting decisions as transplant shock was very widespread. There was a return of extremely dry conditions in August that extended through nearly the entire curing season. It was the driest field conditions that most burley and dark tobacco growers have experienced since 2012, and the driest curing season that many growers could recall. 2022 further emphasized the importance of access to irrigation to sustain the tobacco crop through extended dry periods in the field, as well as tight barns that allow management of air-flow to moderate the effects of dry curing seasons.
PR-825: 2022 Annual Grass Report Warm Season and Cool Season (Cereals)
Bill Bruening, Jimmy Henning, Gene Olson, Ray Smith, Chris Teutsch | Dec. 19, 2022 (New)
Summer annual grasses provide an important forage crop option for producers in Kentucky. These grasses are mainly used as emergency or supplemental pasture, silage, or hay crops, but little information is available on their yield potential. The purpose of this publication is to summarize the University of Kentucky 2008-2021 forage yield trials with sudangrass, sorghum/sudangrass, forage sorghum, millets, teff, crabgrass, and cereal crops.
PR-823: 2022 Cool-Season Grass Grazing Tolerance Report
Jimmy Henning, Gene Olson, Tim Phillips, Ray Smith, Chris Teutsch | Dec. 19, 2022 (New)
Cool-season forages such as tall fescue, orchardgrass, and Kentucky bluegrass are the primary pasture grasses in Kentucky. Other species such as perennial ryegrass and festulolium can also be used in pasture systems. Little is known about the effect of variety on the grazing tolerance of these cool-season grass species.
PR-826: 2022 Long-Term Summary of Kentucky Forage Variety Trials
Jimmy Henning, Gene Olson, Ray Smith, Chris Teutsch | Dec. 19, 2022 (New)
Forage crops occupy approximately 7 million acres in Kentucky. Forages provide a majority of the nutrition for beef, dairy, horse, goat, sheep, and wildlife in the state. In addition, forage crops play a positive environmental role in soil conservation, water quality, and air quality. There are more than 60 forage species adapted to the climate and soil conditions of Kentucky. Only 10 to 12 of these species occupy the majority of the acreage, but within these species there is a tremendous variation in varieties.
AGR-268: Evaluating Cool-season Perennial Grass Pastures using the UK Horse Pasture Health Score Card
Krista Lea, Ray Smith | Dec. 19, 2022 (New)
Providing quality forage is essential to horse health, and pasture can provide a significant portion of the horse's forage needs. Objective evaluation of a pasture's condition can help determine appropriate pasture management practices. The UK Horse Pasture Health Score Card can be used to evaluate horse pastures and determine what improvements should be made.