Agronomy and Crop Sciences Commons^™

1990 Kentucky Winter Annual Legume Variety Test, L. M. Lauriault, Norman L. Taylor, Jimmy C. Henning, W. T. Edmonson

Agronomy Notes

Cover crops are often used in Kentucky following the harvest of row crops such as tobacco, corn, and soybeans. Living cover crops can prevent erosion, reduce leaching of nutrients, and supply grazing, green manure, or a plant cover in which to no-till the following spring.

1990 Kentucky Red Clover Variety Test, L. M. Lauriault, Norman L. Taylor, Jimmy C. Henning, W. T. Edmonson

Agronomy Notes

Red clover is a high quality, shortlived perennial legume that is used in mixed or pure stands for pasture, hay, silage, green chop, and soil improvement. This species is adapted to a wide range of climatic and soil conditions and therefore is very versatile as a forage crop. Stands are generally productive for two or three years with the highest yields occurring in the year following establishment. Red clover is used primarily as a renovation legume for grass pastures. It is the dominant legume in Kentucky because it is high in seedling vigor, quality, yield, and animal acceptance.

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.

Response Of Soybeans To Available Potassium In Three Kentucky Soils, John H. Grove, William O. Thom, Lloyd W. Murdock, James H. Herbek

Agronomy Notes

Soybeans are produced in nearly all of Kentucky's soil physiographic regions. Soybean response to potassium (K) fertilization and soil test Kvaries with soil type and location. This variation may be associated with the wide range in soil chemical and mineralogical properties among the different regions. Of particular interest are differences in that level of soil test Kat which no further yield response to K fertilizer application would be expected. The main objective of this work was to evaluate the soil K-soybean response relationship on three different field sites where soybean yields were increased by fertilizer K. Several measures of soil …

Soil Test Potassium As An Indicator Of Tobacco Response To Band Application Of Fertilizer, J. L. Sims, Kenneth L. Wells, E. C. Schwamberger

Agronomy Notes

During the past 10 years, several studies have been conducted at Lexington on the University of Kentucky Experiment Farm to compare the effect of banding fertilizer 10 to 12 inches to each side of the row with preplant broadcast applications on growth and yield of burley tobacco. Generally, banding most of the nitrogen and potassium has led to fewer problems with salt and manganese toxicity and to improved growth during the early season. However, as compared to broadcast application, banding has had varying effects on cured leaf yields. In 'some experiments banding resulted in higher yields, in other experiments in …

Effect Of Fertilizer Rates And Placement Practices On Yield Of Burley Tobacco, Kenneth L. Wells, G. D. Cantrill, J. L. Sims

Agronomy Notes

Management of fertilizer practices in production of burley tobacco is very important in control of manganese (Mn) toxicity of the crop. In addition to the use of agricultural limestone, the use of fertilizers in the appropriate amounts, the appropriate kinds, and in the appropriate manner can strongly influence acidity in the rooting zone during the growth of burley. Studies of these effects have made up a major thrust of the University of Kentucky's research programs on fertility of burley, and have largely been conducted by J.L. Sims and his students during the past 15 years.

Use Of Molybdenum In The Transplant Water For Burley Tobacco, J. L. Sims, Jones H. Smiley, M. E. Suchy, A. M. Wallace

Agronomy Notes

The need for adding molybdenum to tobacco arises because contents in Kentucky soils generally are on the "borderline" of sufficiency and because amounts of available molybdenum in soil are low when soil pH is low. Soil pH in tobacco fields at midseason often is 0.5 to 1.0 pH unit lower than prior to fertilization. primarily because of the high rates of commercial fertilizers commonly applied to tobacco. This acidity greatly lowers the availability of molybdenum to tobacco plants. That is why we recommend the use of molybdenum when soil pH before fertilization is 6.4 or below.

Corn Yields From Fertilizer Recommendations Made By Some Soil Testing Laboratories Serving Kentucky, Lloyd W. Murdock, William Hendrick

Agronomy Notes

One of the most economically important services available to Kentucky farmers is that of soil testing and fertilizer recommendations. Fertilizer purchases on the order of 150 million dollars per year are currently made by farmers in Kentucky. Until about 30 years ago there was no routine, rapid method for analyzing soils to determine fertilizer needs. Since then, as better methods were developed, soil testing laboratories have been set up for routine farmer use. For many years only the soil testing service provided through the University of Kentucky (UK) was readily available to farmers in Kentucky. Even though the University still …

Zinc Fertilization Of Corn In Kentucky, W. W. Frye, H. F. Miller, Lloyd W. Murdock, D. E. Peaslee

Agronomy Notes

Of the agronomic crops, corn is especially sensitive to zinc deficiency. The major symptom of zinc deficiency in corn is broad white stripes in the leaves at or near the growing point in the early growth stages of the plant. It has been referred to as "white bud" disease because of the characteristic whitish area on one or both sides of the midrib near the base of new leaves. It can be seen as a new leaf unfolds from the whorl. Growth is stunted resulting in shorter than normal internodes. The pith of the stalk may become darkened at the …

Boron Fertilization Of Corn In Kentucky, Lloyd W. Murdock, Kenneth L. Wells, H. F. Miiller

Agronomy Notes

The need for use of boron (B) for alfalfa production has been recognized for many years in Kentucky and is presently recommended for general use as an annual topdressing on alfalfa fields. Use of B is also recommended in Kentucky for red clover fields which are to be harvested for seed. In recent years, there has been interest in use of fertilizer B for good corn production in Kentucky. Plant available B is greatly affected by soil pH and decreases with increasing soil pH. Because of this, some states recommend use of B on corn grown on soils with a …

Manganese Fertilization Of Soybeans, Lloyd W. Murdock, Harold F. Miller, Doyle Peaslee, Wilbur Frye

Agronomy Notes

Only a small quantity of manganese is essential for plant growth however under certain soil conditions even this is not available to the plant. Depending on severity, manganese deficiency will retard plant growth and may drastically decrease yields. A deficiency of manganese will affect the photosynthesis system of the plant. The visual symptoms of a manganese deficiency on soybeans is interveinal chlorosis of the leaves. The veins remains green until the chlorosis nears the white stage then they also lose their color.

Alfalfa Response To Varying Rates Of Phosphorus And Potassium Fertilization On Deep, Red, Limestone - Derived Soils Of The Pennyroyal Area In Kentucky, H. C. Vaught, Kenneth L. Wells, K. L. Driskill

Agronomy Notes

The Western Pennyroyal area of Kentucky consists largely of deep, well-drained limestone-derived soils occurring on an undulating to rolling landscape. A thin loess mantle overlies the limestone residuum in many areas. Soils on these landscapes are capable of good crop production, providing the basis of the rather intensive grain-hay- tobacco-livestock farming systems common to the Pennyroyal area. Because of the well-suited physical characteristics of these soils, alfalfa is a very important hay crop to this area.

Growth Response Of Kenhy Fescue To Nitrogen Fertilizer, Kenneth L. Wells, Robert C. Buckner, George Armstrong, Paul Gray, C. E. Wyatt

Agronomy Notes

Kenhy fescue is a new, improved variety of tall fescue which has recently been released by the University of Kentucky Agricultural Experiment Station and the U.S.D.A. Agricultural Research Service (see University of Kentucky publication AGR-60, "Kenhy A New Tall Fescue Variety"). Seed of this variety should become available to farmers in limited quantities in the summer 1977. The purpose of this report is to provide information on how this newly developed fescue variety produces as affected by time and rate of nitrogen application.

Comparisons Of Nitrogen Fertilizer Sources Under Kentucky Soil And Climatic Conditions, Kenneth L. Wells, Lloyd W. Murdock, Harold F. Miller

Agronomy Notes

A summary of yield data comparing different nitrogen fertilizer sources in field experiments conducted by the Agronomy Department staff should provide information that will help answer some of the inquiries regarding the comparative value of some of the nitrogen fertilizers being marketed in Kentucky. Since the nitrogen rates per acre shown in all tables are ACTUAL NITROGEN the COST PER POUND OF NITROGEN in the different materials is an important consideration when evaluating the various products.

Influence Of Time Of Application Of Nitrogen Fertilizer On Corn Yields, Harold F. Miller, Kenneth Wells, Morris J. Bitzer, G. W. Thomas, R. E. Phillips

Agronomy Notes

Soil moisture conditions can have a large effect on crop responses to nitrogen fertilization. Kentucky's usual climatic pattern of periods of heavy rainfall and relatively warm temperatures during the winter and spring seasons influences expected yield responses of corn to applied nitrogen. If nitrogen fertilizer is applied in late winter or early spring, some of it may be lost before the plants have made sufficient growth to take up appreciable quantities. The amount of loss that might be expected will be influenced by the amount of rainfall, temperature, amount of organic matter and drainage of the soil.

Effect Of Topdressing Different Forms Of Nitrogen Fertilizer On Corn, Doyle Peaslee, Morris J. Bitzer, Harold F. Miller

Agronomy Notes

Nitrate nitrogen is the dominant form of plant-available nitrogen in soils, since even ammonium nitrogen is rapidly converted to nitrate nitrogen under Kentucky field conditions. Nitrogen in the nitrate form can be lost by leaching in the drainage water and by denitrification when the soil is saturated with water for a relatively short period of time. With the increased cost and short supply of nitrogen fertilizers, it is especially important that applications be made at a time and in a way that will minimize losses.

Tall Fescue Seed Production In Kentucky, Dennis M. Tekrony, C. J. Kaiser, Warren C. Thompson, Robert C. Buckner

Agronomy Notes

Producing tall fescue seed has traditionally been a profitable venture for many Kentucky farmers. It can still provide additional income if: (1) it is properly managed and fertilized and (2) it is integrated into a total farming program which in most cases includes livestock.

Effect Of Nitrogen Fertilization On Yield Of Burley Tobacco, J. L. Sims, W. O. Atkinson, Jones H. Smiley, Allen M. Wallace

Agronomy Notes

Relatively large amounts of nitrogen from fertilizers and manures commonly are used in burley tobacco production. Growers are currently estimated to apply between 150 and 400 pounds of actual N per acre. Fertilization of burley with nitrogen significantly affects the physical and chemical characteristics of cured leaf and produces changes in yield and value. On most soils, leaf yields usually are increased by applications of N fertilizer, but the amount of yield increase per unit of applied fertilizer N varies widely between soils. High rates of N applied preplant or at planting often retard early plant growth, delay maturity, and …

Fertilizing No-Till Corn, John L. Ragland, John Masterson, C. R. Belcher

Agronomy Notes

Results of an experiment conducted in 1968 at Princeton, Kentucky on low phosphate soil showed that surface-applied phosphorus was sufficiently available to no-till corn to produce good yields. This experiment was repeated again in the 1969 growing season with the results well in line with those reported for 1968 in Agronomy Research (Misc. 377) pages 41-43.

Summary Of Fertilizer Use And Estimated Use Of Plant Nutrients On Tobacco, Corn, Hay And Pastures In Kentucky, Kenneth L. Wells

Agronomy Notes

Nearly 650, 000 tons of fertilizer were used by Kentucky farmers during the first half of 1969. Plant food content (N+P₂O₅ + K₂O) was 38%, or nearly 247,000 tons. Slightly over half (58%) was sold in bagged, one-third (33%) in bulk, and 8% in fluid form. Mixtures made up 70% of the total tonnage, and materials made up 30%. The statistics tabulated below show a more detailed breakdown of the fertilizer tonnage used.

What Happens To Fertilizer Nitrogen In The Soil?, W. O. Atkinson, John L. Ragland

Agronomy Notes

What happens to the nitrogen a farmer applies as fertilizer each spring?

First, let us consider the forms of nitrogen normally applied, and then attempt to trace what happens to the nitrogen once it is added to the soil. The average complete fertilizer contains approximately 70 percent of its nitrogen in the ammonium nitrogen form (NH4), about 10 percent in the urea form (this is quickly converted to ammonium nitrogen), and the remaining 20 percent in the nitrate nitrogen form (NO₃) .

Fertilizer-Insecticide Mixtures On Corn, R. A. Scheibner, George D. Corder

Agronomy Notes

Soil fertility and insects are major factors that affect corn yields. The proper kinds and amounts of fertilizers and insecticides when used properly will make corn production more economical on fields where either or both are needed.

Boron Carrying Compounds, George D. Corder

Agronomy Notes

Boron is available on the market in a number of different compounds, but three new boron-carrying materials have recently come on the market. Since the boron content of each compound is different, the concentration will determine the rate required per acre.

Response Of Corn To Broadcast Applications Of Zinc, Harold F. Miller

Agronomy Notes

Where zinc deficiency in corn occurs on Kentucky soils it has been corrected by applying 3 to 6 pounds of elemental zinc per acre in the row at planting time. In some areas of the state, corn planters with row fertilizer attachments are not generally used, raising the question as to library the amount of zinc required when broadcast applications are made.

Through the cooperation of Clarence Mitchell, Area Extension Specialist, a field was located where the 1966 corn crop showed zinc deficiency. Since the field was to be planted in corn (Connecticut 860) in 1967, a field trial with …

Apply Fertilizer And Limestone This Fall, George D. Corder

Agronomy Notes

As farmers push towards more economical crop production, fertilizer and limestone use will increase. If Kentucky farmers continue to help feed the world, the rate of increase will accelerate during the next decade .

Nitrogen Loss From Surface Application, Harold F. Miller

Agronomy Notes

Research work has shown that considerable nitrogen can be lost from surface applied ammonia-containing fertilizers. The nitrogen is lost due to the formation of ammonia which escapes into the air. Soil and weather conditions encouraging this loss are high temperature, moist soils, high pH and source of nitrogen.

Agronomy Notes, No. 35, Robert C. Buckner, Paul B. Burrus Jr.

Agronomy Notes

The following table gives the effect of clipping and fertilization treatments on clean seed yields of tall fescue. Seed yield figures are averages of four replications and five years' data.

Borax, Borates, And Other Boron-Carrying Compounds, Harold F. Miller

Agronomy Notes

Boron is available on the market in a number of different compounds. Since the amount of boron contained in each compound is different, the concentration will determine the rate required per acre. Frequently, all of these boron-containing compounds are erroneously referred to as borax (11.36 percent boron).

Fertilizer-Insecticide Mixtures On Tobacco Plant Beds And Fields, George D. Corder, R. L. Miller

Agronomy Notes

Fertility and insect control programs have a major influence on tobacco production. The proper amounts and kinds of fertilizers and insecticides properly placed will make production more economical on beds and fields if either or both are needed.

Is a fertilizer-insecticide mix the best way to meet the fertility needs and t he insecticide needs on tobacco? The following questions and answers should help show how the decision was reached that this method is not recommended.

Changes In Soil Ph Caused By Heavy Nitrogen Fertilization, W. O. Atkinson

Agronomy Notes

Ammonium nitrate, ammonium phosphate, ammonium sulfate, urea and anhydrous ammonia leave acid residues, thus tending to make the soils more acid. The degree to which soil pH may be affected and the persistence of such changes for a silt loam soil is shown in the table below. The same amounts of phosphorus and potash were applied to all plots, and the different amounts of nitrogen were supplied from ammonium nitrate. Burley tobacco was the crop grown and the data are for 1963, which was the second consecutive year for the fertilizer treatments. (These were experimental plots and the high treatments …