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2002-2003 Kentucky Canola Variety Performance Test, Greg Schwab, Lloyd W. Murdock, James H. Herbek, Chad Lee, David Van Sanford

Agronomy Notes

Winter canola is a crop that is well suited for Kentucky’s climate and crop rotation, but production peaked at 20,000 acres in 1989and has since declined mainly due to winter hardiness concerns. Changes in the 2002 farm bill have once again caused farmers to consider converting some of their wheat acreage to canola production. For the past several years, plant breeders have been working to improve canola’s winter hardiness and have released several varieties that seem to be better suited for Kentucky’s variable winters than the varieties grown in the late 1980s. A study was initiated in the fall of …

Phosphorus Soil Test Change Following The Addition Of Phosphorus Fertilizer To 16 Kentucky Soils, William O. Thom, James E. Dollarhide

Agronomy Notes

When applying phosphorus to soils it is important to know how much the soil test P changes with the addition of various rates. Soils are different in how they respond to varying rates of application, and only limited information is available for Kentucky soils.

Zinc Fertilizer Rates And Mehlich Iii Soil Test Levels For Corn, Lloyd W. Murdock, Paula L. Howe

Agronomy Notes

Zinc (Zn) is the micronutrient most often deficient for corn in Kentucky. This problem occurs every year but is more commonly seen in years with a cool, wet spring. Although the environment, soil type and past erosion each have an effect, the most important factors controlling plant available Zn are the soil pH, extractable soil phosphorus (P) and extractable soil Zn. While the amount of Zn in the plant increases as the available soil Zn increases, increasing levels of soil P and pH are strongly associated with reduced levels of Zn in the plant.

Trends In Alfalfa Production And The Beef And Dairy Industries In Kentucky During 1989-98, Dennis Hancock, Michael Collins

Agronomy Notes

On suitable soils, alfalfa produces the highest yield of nutrients possible from a perennial forage crop. However, high production costs and restrictive soil requirements have limited the production of alfalfa in Kentucky. High producing dairy cows respond well to premium quality forage, so alfalfa is a preferred forage crop in dairy production. Thus, alfalfa production is primarily contingent on the producer’s method of marketing the crop.

The Effect Of Drying Soil Samples On Soil Test Potassium Values, Kenneth L. Wells, James E. Dollarhide

Agronomy Notes

Extreme temporal and spatial variability of soil test potassium values (STK) was measured on small plots (12-ft x 40-ft) being used for a STK correlation and calibration study on a Crider soil in Larue County, Kentucky. Twelve periodic samplings of the 20 small plots in this study over a period of 18 months showed as much as two-fold temporal differences in STK within individual plots, many of which had received no potassium (K) fertilizer during the study. Spatial variability of STK also varied as much as two-fold among the individual small plots at any given sampling time for similar treatments. …

Comparison Of Weed Management Strategies With Roundup Ready® Corn, J. A. Ferrell, William W. Witt

Agronomy Notes

Corn weed management during the past several years in Kentucky has centered around two herbicide families, the chloroacetamides (Dual, Frontier, Harness, Micro-Tech, Surpass) and the s-triazines (AAtrex, Bladex, Princep). These products have been used widely because they offer acceptable, full season control of many common warm season annual weeds at a reasonable price. This combination has been so popular that several premixtures that contain these types of herbicides (Bicep II, Bullet, Guardsman, Harness Xtra, Surpass 100, FulTime) are used commonly used in Kentucky. The key to this efficacious and economic program is atrazine because it controls most annual broadleaf …

Small Scale Temporal And Spatial Variability Of Potassium Soil Test Values On A Crider Soil, Kenneth L. Wells, James E. Dollarhide, Frank J. Sikora

Agronomy Notes

An on-farm, small plot study conducted in 1996, on a Crider soil in Larue County, Kentucky, resulted in unanticipated wide variability of soil test potassium (STK) values between spring and fall sampling. Because of this, the small plots were sampled monthly over a period of time with the objective of determining if such variability in STK values was real.

Do Cover Crop Residue And No-Till Increase Poultry Litter Runoff?, M. A. Cooprider, Mark S. Coyne

Agronomy Notes

Manure and litter produced during broiler production are an environmental issue in Kentucky. The most common and practical disposal method is to apply the poultry wastes to pasture and crop land. If the wastes are incorporated by tillage immediately after application to crop land, nitrogen that might otherwise be lost by ammonia volatilization is conserved. However, incorporating wastes is not possible in no-till, which is a best management practice (BMP) used by 51% of Kentucky's farmers to control soil erosion. One question is whether surface application of poultry wastes onto no-till fields could increase fecal bacteria contamination of surrounding waterways …

Early Maturing Varieties And Soybean Cyst Nematodes: Will This Marriage Work?, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Soybean cyst nematode (SCN) is widely distributed in Kentucky’s soybean growing areas. The use of SCN-resistant varieties has long been a recommended production practice for infested fields. However, continuous use of such varieties can result in a shift to a race of SCN which is able to vigorously attack previously resistant varieties. For this reason, many states recommend that producers periodically grow a crop of SCN-susceptible soybeans within a crop rotation when SCN populations are at minimal levels (causing less than a 5% loss in yield). The UK Plant Pathology Department recommends a four year rotation in SCN-infested fields [PPA3; …

Early Maturing Varieties And Soybean Cyst Nematodes: Will This "Marriage" Work?, Colleen C. Steele, Larry J. Grabau

Agronomy Notes

Soybean cyst nematode (SCN) is widely distributed in Kentucky's soybean growing areas. The use of SCN-resistant varieties has long been a recommended production practice for infested fields. However, continuous use of such varieties can result in a shift to a race of SCN which is able to vigorously attack previously resistant varieties. For his reason, many states have long recommended that producers periodically grow a crop of SCN-susceptible soybeans within a crop rotation when SCN populations are too low to cause yield reductions. In Kentucky, the UK Plant Pathology Department recommends a four year rotation in SCN-infested fields [PPA3; "Wanted: …

Kentucky County Soil Sample Summaries, Vern Case

Agronomy Notes

The UK Soil Testing Labs at Lexington and Princeton, KY test 50,000 to 60,000 soil samples each year. Samples are submitted through the county Extension offices for agronomic (Ag) crops, commercial horticulture, home garden/lawn, greenhouse media, and surface mining reclamation. The Mehlich III extractant (M-3) is used for routine determination of phosphorus (P), potassium (K),calcium (Ca), magnesium (Mg) and zinc (Zn). Amounts of these nutrients extracted are determined by either ICP methodology or by color for P and atomic absorption for K, Ca, Mg and Zn. Soil pH is determined on a 1:1 soil:water mix using appropriate electrodes and pH …

An Evaluation Of Twelve Maturity Group Ii Soybean Varieties At Lexington, Kentucky, Larry J. Grabau, Colleen C. Steele

Agronomy Notes

In both 1993 and 1994, the Kentucky Soybean Promotion Board funded an on-farm test of a small set of Maturity Group (MG) II varieties. Those studies showed that several MG II varieties were competitive with a high-yielding MG IV variety. However, other MG II varieties did not perform as well in those tests, indicating that variety selection is an important management consideration if this early maturing cropping system is to be successful in Kentucky soybean producers' fields. MG II varieties used in past University of Kentucky tests have been chosen based on their performance in university variety trials where such …

Lime Source And Rate Effects On Corn Production On An Acid Soil, Kenneth L. Wells, James E. Dollarhide, V. W. Case

Agronomy Notes

Quality of lime available for use in neutralizing soil acidity can be quite variable in Kentucky. This sometimes raises questions of which locally available source is most effective. Information about the quality of individual lime sources is necessary to make such determinations.

Grain Quality Of Early Maturing Soybean Grown In Kentucky, M. V. Kane, Colleen C. Steele, Larry J. Grabau, C. T. Mackown, David F. Hildebrand

Agronomy Notes

Interest in grain quality of US soybean has grown in recent years. For example, in 1990, there was much interest in "component pricing" of soybean grain, Under that plan, growers would be paid a price for their grain that reflected the value of the protein and oil it actually contained, rather than the common price paid to all growers, regardless of any variation in protein and oil content. However, the soybean processing industry is evidently not excited about the complexity of testing individual lots for protein and oil and keeping track of pricing structures depending on those results. As a …

An Evaluation Of Twelve Maturity Group Ii Soybean Varieties At Lexington, Kentucky, Larry J. Grabau, Colleen C. Steele

Agronomy Notes

In 1993, an on-farm study funded. by the Kentucky Soybean Promotion Board showed that the best Maturity Group (MG) II variety tested was quite competitive with the best available MG IV variety. However, other MG II varieties did not fare as well, indicating that careful variety selection will be essential for on-farm success with this MG II cropping system. MG II varieties used in past University of Kentucky tests have been chosen based on their performance in university variety trials where they are normally grown, for example, in Iowa, Illinois, Indiana, and Ohio. Such tests include relatively large numbers of …

Crude Protein Of Hybrid Corn Varieties Evaluated In The Kentucky Hybrid Corn Performance Tests From 1990 To 1993, C. G. Poneleit, K. O. Evans, Michael Collins, Gary L. Cromwell

Agronomy Notes

Grain samples have been collected each year since 1990 from three locations of the Kentucky Hybrid Corn Performance Test and analyzed for crude protein. The objective was to provide an unbiased comparative evaluation of the crude protein content of corn hybrids sold in Kentucky. The results indicate that while management and environment at each test 1ocat i on may have significant influences, crude protein does differ among hybrid genotypes. The feeding value of specific hybrid genotypes based on their protein content may have significant influence in diet formulation for non-ruminant animals owing to the amount of supplement needed to properly …

1993 Kentucky Bluegrass Variety Test Report, L. M. Lauriault, A. J. Powell, Timothy D. Phillips, Jimmy C. Henning

Agronomy Notes

Kentucky bluegrass (Poa pratensis) is the third most prominent cool-season grass used in Kentucky for, forage, behind tall fescue and orchardgrass. As with all cool-season grasses, Kentucky bluegrass does best in cooler weather, becoming dormant in hot, dry conditions. It is a high quality, long-lived, rhizomatous grass that is used for both turf and forage. Compared to other cool-season grasses, Kentucky bluegrass is slower to germinate (2-3 weeks) and generally is lower in seedling vigor and herbage yield. Most recent varieties of Kentucky bluegrass have been developed for turf use; therefore, primary emphasis has been placed on improving …

1994 Kentucky Timothy Variety Test Report, L. M. Lauriault, Timothy D. Phillips, Jimmy C. Henning

Agronomy Notes

Timothy (Phleum pratense) is the fourth most widely sown cool-season perennial grass used in Kentucky for forage, ranking behind tall fescue, orchardgrass, and Kentucky bluegrass. It is a late-maturing bunchgrass that can be used for grazing but is mainly harvested as hay, particularly for horses. For hay production, timothy can be sown with alfalfa or red clover, while white clover or birdsfoot trefoil make good mixtures with timothy for grazing. Management is similar to that for other cool-season grasses. Harvesting at the mid- to late-boot stage is needed to assure good yields and high forage quality. Quality of …

1993 Kentucky Timothy Variety Test Report, L. M. Lauriault, Timothy D. Phillips, Jimmy C. Henning

Agronomy Notes

Timothy (Phleum pratense) is the fourth most widely grown cool-season perennial grass used in Kentucky for forage, ranking behind tall fescue, orchardgrass, and Kentucky bluegrass. It is a late maturing bunchgrass that can be used for grazing but is mainly harvested as hay, particularly for horses. Management is similar to that for other cool season-grasses. Harvesting at the proper stage of maturity (mid- to late-boot) is needed to assure high forage quality; otherwise, quality of timothy declines more rapidly than other cool-season grasses as it overmatures. In Kentucky, timothy behaves like a short-lived perennial with stands lasting for …

Trends In Cropland Acreage And Fertilizer Use In Kentucky Since 1980, Kenneth L. Wells

Agronomy Notes

Cropland acreage and patterns of fertilizer use varied considerably during the period 1980-1991. Variation in cropland acreage is largely related to commodity prices, available markets, land ownership patterns, and government programs. Patterns of fertilizer use are affected by cropland acreage, the nature of the fertilizer supply industry in Kentucky, weather, and improved efficiency in use of time and labor by farmers. The situation in the early 1990's is different than it was in 1980, and the following discussion highlights changes that have taken place. Fertilizer use data are those reported by the University of Kentucky's Division of Regulatory Services in …

Triazine Resistant Pigweeds In Kentucky Corn Fields, Jonathan D. Green, Michael Barett, Mike Radford

Agronomy Notes

Smooth pigweed (Amaranthus hybridus) control from atrazine and/or simazine (Princep) has been unsatisfactory in some Kentucky corn fields. Many of these fields have grown corn where one or both of these herbicides have been used continuously for several years. These two triazine herbicides, particularly atrazine, are used annually on over 90% of the corn grown in Kentucky. Other areas in the U.S. and around the world have reported. unsatisfactory control from atrazine where triazine resistant pigweed has developed.

Potential Use Of Ethephon To Control Lodging Of Soybeans, Larry J. Grabau, Robert C. Pearce, J. V. Konsler

Agronomy Notes

Lodging is sometimes a serious problem with soybeans in Kentucky, especially with the full season crop. However, under, excellent growing conditions, or if planting rates are too high, substantial lodging of double crop soybeans can also occur. If lodging occurs early during seed fill, it can reduce yields directly by causing poorer light use and increasing diseases. If lodging occurs late during seed fill, it will have little direct effect on yield, but may have an indirect effect by slowing down harvest and increasing harvest losses. Thus, the use of an inexpensive chemical to reduce soybean lodging is attractive. Our …

Stubble Losses Of Kentucky Soybeans, Larry J. Grabau, Todd W. Pfeiffer

Agronomy Notes

Double crop soybeans in Kentucky tend to be shorter than plants from full season plantings. Since lowest pod height is related to plant height, double crop soybeans may be subject to greater harvest losses due to pods remaining below the level at which the combine header is operated. While it would be possible to lower the header closer to the soil to pick up some of those pods, that would slow down harvest and increase the risk of picking up stones and other trash. Although the actual cutting heights used in Kentucky are not known, some producers use combines with …

Forage Production On Reclaimed Surface Mined Land In Eastern Kentucky, William O. Thom, H. B. Rice

Agronomy Notes

Forage crop production for hay or pasture can be important for the utilization of the many acres of reclaimed surface mined land in eastern Kentucky. Even though grasses and legumes are seeded during reclamation to provide ground cover and reduce soil loss, these areas are not usually managed for forage crop production. On the other hand, these vast land areas have the capability to provide significant amounts of desirable grasses or grass-legume mixtures for cattle when well-managed.

1987 Update Of Agronomic Performance Of Tall Fescue Varieties, Paul B. Burrus Ii, Garry D. Lacefield, J. Kenneth Evans

Agronomy Notes

Tall fescue (Festuca arundinacea, Schreb.) is a well adapted, widely used pasture species occupying approximately 5.5 million acres in Kentucky and 35 million acres in the south central United States.

Commercial tall fescue varieties have been developed from plant materials of either northern European or Mediterranean origin. Varieties developed at the University of Kentucky -- Kentucky 31, Kenmont, Kenwell, Kenhy, and Johnstone -- trace to plant materials of northern European origin. The Kentucky varieties have later maturity dates and have greater resistance to certain foliar diseases during summer than varieties that are of Mediterranean origin (i.e., Alta, Fawn, Goar, and …

Adjusting Soil Ph On Heavy Textured Soils Of The Eden Hills, Kenneth L. Wells, R. M. Jones

Agronomy Notes

The Eden Hills Area (also known as The Hills of the Bluegrass) of Kentucky lies adjacent to the Inner Bluegrass Area in a crescent shape within which a large area of several counties occur. Carroll, Owen, Grant, Gallatin, Pendleton, and Robertson Counties occur almost entirely within this physiographic region and several other counties have sizable acreages within it. Soils of the area have formed largely on Ordovician aged calcareous siltstones of the Garrard Formation and interbedded calcareous shales, thin limestones, and siltstones of the Eden Formation. Soils developed from these formations occur on strongly sloping to steep landscapes and have …

Row Widths For Full Season Soybeans In Kentucky, Todd W. Pfeiffer, Morris J. Bitzer, James H. Herbek, Jereme Orf, D. Pilcher, Charles Tutt, L. Zen

Agronomy Notes

Soybean yields in Kentucky have increased steadily in the past 20 years as a result of improved varieties and production practices. To achieve even higher yields new varieties and better production practices need to be developed and tested. One possibility for increasing soybean yields is to plant in narrow rows using varieties which respond to this practice. Although previous research in Kentucky has not shown a yield advantage for full season soybeans planted in narrow rows, researchers in other states have recently shown increases in yield with narrowing row widths. A number of new varieties have also been developed specifically …

Summary Of Alfalfa Variety Trials In Kentucky (1971-1983), Roy E. Sigafus

Agronomy Notes

This note shows comparable yields for 22 out of 100 alfalfa varieties which have been tested in at least three trials at Lexington or Princeton since 1971. Varieties not listed include many taken off the market, varieties known to be unsuited to Kentucky, or those which need further testing.

Yield results from seven separate trials are given in Table 1 as average annual dry matter yields (T/A) and as % relative yield (RY) as compared to Vernal. Vernal was used in each trial as a standard check and on the soils of limestone origin at Lexington and Princeton averaged over …

Fertilization Practices For Double Cropping Systems, John H. Grove

Agronomy Notes

Double cropping has become an important practice in the state of Kentucky. While the wheat-soybean grain intensive production system is the most widely used on an acreage basis (approx. 3/4 million acres per year) several other systems are being adopted by Kentucky growers. Most of these involve some silage production for beef and/or dairy cattle. The fall seeded small grain (wheat, barley, triticale) is harvested at an immature stage of growth and ensiled and a subsequent crop for silage (corn, grain sorghum) or grain (soybean, grain sorghum) is planted. The use of reduced and no-tillage management will speed up planting …

An Estimate Of The Soil Fertility Status Of Graves And Todd Counties In Kentucky, Kenneth L. Wells, D. E. Peaslee, Marvin Davidson, William Green

Agronomy Notes

Some concern has developed during recent years that fertilizer is being used by farmers on fields with residual levels of P and K high enough that such use is not justified as a means of increasing crop yields. This has been due to increased "average" soil test values for samples routinely submitted to college soil test laboratories.

For this reason, studies were conducted in Graves and Todd Counties in Kentucky during the period September, 1978 to September, 1980, to determine if soil samples routinely submitted to college test laboratories do or do not accurately reflect the average soil fertility status …