Numbered Publications: Plant and Soil Sciences
AGR-273: Soil Acidity: What It Is, How It Is Measured, Why It Is Important
John Grove, Edwin Ritchey | Apr. 13, 2023 (New)
Soil chemical health is strongly related to soil acidity. This acidity consists of acidic cations, hydrogen (H+), aluminum (Al3+), and in some soils, manganese (Mn2+). The acid cations are neutralized by basic anions, carbonate (CO32-), hydroxyl (OH-), and oxide (O2-) provided by materials such as agricultural, hydrated/slaked, and quick/burnt limes, respectively. Lime application rates are based on the amount of acidity measured in your soil sample.
ID-274: Economic Efficiency in Organic Dairy Operations
John Allison, Kenny Burdine, Ray Smith | Apr. 3, 2023 (New)
Organic dairy operations have historically commanded a higher milk price than conventional dairy operations (Organic all milk price 2021 average: $31.55 per hundredweight (USDA AMS, 2021), Conventional all milk price 2021 average: $20.25 per hundredweight (USDA ERS, 2021)). However, the economics of decision-making and management still play a pivotal role in farm profitability.
AGR-270: Restoring a Flood-damaged Lawn
Kenneth Clayton, Paul Andrew Rideout, Jason Vaughn, Beth Wilson | Mar. 14, 2023 (New)
Flooding across Kentucky has been an increasing problem in recent years and has caused significant damage to many properties, including home lawns. The deterioration or death of turfgrass is often caused by grass being smothered with silt and sand deposits left from the flood or grass being submerged under water for prolonged periods. Lack of oxygen to the plant can cause death when submerged, and the rate of death is often worse with higher water temperatures. Repairing these areas is important for reducing chances of erosion as well as allowing a return to the regular use of the lawn.
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-1: Lime and Fertilizer Recommendations, 2020-2021
Josh McGrath, Edwin Ritchey | Mar. 13, 2023 (Revised)
Recommended nutrient additions, based on a soil test, are only made when a crop yield or economic response has been measured for that crop under Kentucky soil-climatic conditions. Many field studies have been conducted by the Kentucky Agricultural Experiment Station under Kentucky farm conditions to determine the extent of any primary, secondary, or micronutrient needs. Yield and soil test data from these studies serve as guidelines for establishing recommendations contained in this publication. Recommendations in this publication strive to supply the plant nutrients needed to achieve maximum economic return assuming good management practices.
ID-123: Livestock Waste Sampling and Testing
Doug Overhults, Monroe Rasnake | Mar. 13, 2023 (Revised)
It is estimated that about 25 million tons of animal manure are currently produced on Kentucky farms each year. Most of this is deposited by grazing animals on pastures where the nutrients are recycled. However, an increasing percentage is accumulated in feed lots, barns, poultry houses, lagoons, and other facilities until it can be spread on the land.
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.
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.