Physical Sciences and Mathematics Commons^™

Evaluating P And K Fertilizer Prescriptions From Site-Specific Technologies, John H. Grove, E. M. Pena-Yewtukhiw

Soil Science News and Views

Developing a field's fertilizer prescription as a part of a site-specific nutrient management plan can be one of the more costly tasks undertaken. Those costs are traditionally associated with gathering of a number of plant and/or soil samples, their testing, as well as acquiring and applying amendments. Soil sample analysis is particularly important for traditional phosphorus (P), potassium (K) and soil acidity (pH) management. Soil sampling requires skill and time, time that may be in short supply when crop harvest is to be soon followed by establishment of a succeeding crop. Soil test results are not always timely, further delaying …

Effect Of Avail® Polymer Applied To Phosphorus Fertilizers On Dry Matter Production And P Uptake Of Fescue At Princeton, Ky, Lloyd W. Murdock, John James Olson, Gene Olson

Soil Science News and Views

A study was conducted near Princeton, KY to determine if a polymer (AVAIL^®) applied to diammonium phosphate (DAP, 18- 46-0) and mono ammonium phosphate (MAP, 11-52-0) would increase (P) phosphorus use efficiency in fescue production on a low P testing soil, when compared to an untreated phosphate fertilizer. AVAIL^® (Specialty Fertilizer Products, Belton, MO) is presently being sold in Kentucky as a product to improve phosphorus fertilizer efficiency.

On-Farm Field Research: Setting Up A Valid Comparison, John H. Grove

Soil Science News and Views

Producers now have the tools (grain carts with load cells, yield monitors, GPS) to do on-farm field research. Additionally, growers are being made aware of more and more products/management options that they might use. One might read farm magazines, talk to neighbors, attend extension and industry presentations, but still wonder whether a particular recommendation would be of benefit. So the question remains. How would this (product, change in management) work on the land that I farm? Tools plus uncertainty equals motivation for an on-farm comparison.

The Corn Belt Multi-State Corn Nitrogen Rate Calculator: Not Reliable For Kentucky Corn Producers, John H. Grove, Gregory J. Schwab

Soil Science News and Views

Because of the rising price of nitrogen (N) fertilizer, university personnel across the country are in the process of fine tuning N recommendations for com. Historically, each state has had different N recommendations based on research results obtained in different production systems and growing environments across each state. Some states in the Com Belt have used a yield potential (yield goal) approach to N recommendations. The expected yield is multiplied by a factor (usually 1.2) and then N credits for previous crop, manure, etc. are subtracted. One problem with this method is that as com yields increase N recommendations also …

On-Farm Field Research: Replicating Your Valid Comparison, John H. Grove

Soil Science News and Views

On-farm research is motivated by a desire to learn more about a product/practice/system on land you manage. You may now have the tools (yield monitor, weighing grain cart, etc.) to accomplish on-farm research that generates information you can use in management decision-making. Your on-farm research should start with the design of a ''valid comparison", according to your research objective (Soil Science News & Views 26:01).

Precision Farming In Central Kentucky: Evaluating Public And Private Sector Influence On The Adoption Decision, Rod Grusy

Soil Science News and Views

The Cooperative Extension Service is challenged to assess the needs of customers who are unable or unwilling to try new production techniques with the potential to increase profitability. Precision Farming (PF) is a production technique that has the goal of maximizing economic potential by using technology that recognizes variability within fields. Ample research from the last decade shows that precision technologies hold promise for enhanced agricultural profitability. A study conducted in three Central Kentucky counties in 2001 shows that farmers obtain information for decision-making related to PF technologies from their local fertilizer dealer and the Cooperative Extension Service but are …

Value Of Nutrients In Poultry Litter When Applied In The Fall, Monroe Rasnake, George Kelley

Soil Science News and Views

The value of nutrients in poultry litter depends not only on how much nitrogen (N), phosphorus (P) and potassium (K) it contains, but also on how it is handled and applied. The following table compares the value of 19 poultry litter samples from Hopkins County analyzed for N, P & K and the litter then spread in the fall. The samples include pullet, breeder and broiler manures, with storage times up to one year. Nutrient values were based on a comparison with urea (46-0-0) at $199/ton, triple super phosphate (0-46-0) at $215/ton and muriate of potash (0-0-60) at $165/ton.

Effect Of Magnesium And Sulfur Fertilization Of Alfalfa, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

In response to concerns that high yields of alfalfa need to be fertilized with sulfur (S) because of soil depletion of S and less S entering the soil from atmospheric fallout, studies were conducted during 1998-1999, to test for S response by alfalfa. Additionally, alfalfa was tested for magnesium (Mg) response because previous hay analysis from the study site had shown very low levels of Mg.

Irrigated Field Crop Acres In Kentucky, Lloyd W. Murdock

Soil Science News and Views

Irrigation in Kentucky has always been limited. This is due to a limited water supply in many parts of Kentucky and the high amount of rainfall in the state which reduces the chances for a consistent profitable response to field crops.

Soil Testing For Agronomic And Environmental Uses, William O. Thom, Frank J. Sikora

Soil Science News and Views

Soil testing is a program that includes taking samples from a field or site, performing a laboratory analysis, and making recommendations for lime and crop nutrients. Good results from this program depend on several supporting factors: (I) obtaining samples representative of the soil in a field area or site; (2) using good techniques in the laboratory that give accurate indications of the nutrient status of the sampled area; and (3) having an extensive data base for making lime and nutrient recommendations from the analytical results.

Drawdown Of Soil Test Phosphorus And Potassium Levels By Alfalfa, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Alfalfa hay production removes large amounts of phosphorus (P) and potassium (K) from soils. Because of this, there is always interest in the reduction of soil test phosphorus (STP) and soil test potassium (STK) levels by high-yielding alfalfa. Periodic soil sampling for 2 years during an on-farm· fertilizer study on a high yielding alfalfa field provided an insight into this.

Lime Rate Adjustments Based On Rnv And Depth, William O. Thom

Soil Science News and Views

Agricultural limestone quality is measured by its neutralizing value and fineness of grind. Neutralizing value is determined by calcium carbonate equivalent (CCE). The higher the CCE, the greater the limestone’s ability to neutralize soil acidity. Reaction rate in the soil is affected by fineness of grind, with finer materials reacting faster with a soil to increase pH. Methods have been developed to calculate efficiency factors that involve using both CCE and material fineness. Regardless of the aglime material used, when the same amount of effective neutralizing material is applied and mixed thoroughly with the soil, the pH change in the …

Subsoiling Of No-Tilled Corn, Lloyd W. Murdock

Soil Science News and Views

No-tillage corn production has become very popular in Kentucky because of the advantages it offers producers. Currently, over half of the corn in Kentucky is planted by this method and even a higher percentage is no-till planted on erodible lands. Because of this, many fields have received little tillage in the last 10 to 20 years. Many producers wonder if soil compaction increases with time on these long-term no-tilled fields due to annual trafficking by heavy equipment. Subsoiling implements have become available that allow subsurface tillage while preserving the surface mulch layer. This practice allows for continued no-till planting while …

No Tillage Use For Crop Production In Kentucky Counties In 1998, Gerald R. Haszler

Soil Science News and Views

For the past several years, we have reported the status of no~tillage adoption in Kentucky counties. Now, CTICt has published the results for 1998. In 1994, 44% of all crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51 % . In 1997, it dropped to 48% and remains at 48% for 1998. Results for the leading no-till states for 1994, 1996, 1997 and 1998 are shown in Table 1. The percentage of major grain crops (com, soybeans and small grains) grown under no tillage in Kentucky are shown by county in Figure 1. …

No Tillage Use For Crop Production In Kentucky Counties In 1997, G. R. Haszler

Soil Science News and Views

Three years ago (1994) and again last year (1996), we reported the status of no-tillage adoption in Kentucky counties. Now, CTIC has published the results for 1997. As before, Kentucky leads the nation in percent of all crops produced under no tillage, but the percentage has slightly decreased from 1996. In 1994, 44% of all crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51% . It dropped to 48% in 1997. The results for 1994, 1996 and 1997 are shown in Table 1. The percentage of major grain crops (corn, soybeans and small …

Precision Agriculture: A Field Study Of Soil Test Variability And Its Effect On Accuracy Of Fertilizer Recommendations, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of precision agriculture techniques in Kentucky during the past several years has generated interest in how to soil sample a field for use in programming computer-driven, on-the-go, variable rate fertilizer spreaders (VRS). The advantage achieved by VRS is related directly to variability of soil test (ST) values within a specific field and the accuracy of how they represent the field. Since variability of ST values commonly exists on a small scale, a very intensive sampling procedure (grids of one acre or less in size) would be required to accurately describe the nature and extent of such variability within a …

Precision Agriculture: The Effect Of Variable Rate Fertilizer Application On Soil Test Values, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of variable rate fertilizer spreaders (VRS) is available to farmers in many areas of Kentucky. For use of VRS, a soil fertility map must be prepared for the field to be spread which requires subdividing the field into subunits. Each subunit is then soil sampled separately. A common procedure in commercial use is to grid a field into 2.5 acre blocks and to take a composite sample of 6-8 cores along the perimeter of a circular radius of 60-80 ft from the center of each block. Each block receives a separate fertilizer recommendation based on results from the soil …

Late Season Supplemental Nitrogen On Double-Cropped Soybeans, Curt Judy, Lloyd W. Murdock

Soil Science News and Views

Soybeans produce their own nitrogen for crop growth with the aid of nitrogen fixing bacteria in the soil that infect the soybean root and form nodules which contain the bacteria. This is a symbiotic relationship that benefits both the plant and the bacteria. The bacteria are able to take atmospheric nitrogen and convert it into a form of nitrogen that the plant can use. Much of the nitrogen requirement for soybean production begins at seed development. Soybean physiology studies suggest that the amount of nitrogen supplied for the soybean plant from fixation in the nodules is less than the potential …

A Two Year Evaluation Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Intensively Row Cropped Agricultural Watershed In Western Kentucky, Larry Reber, John Potts

Soil Science News and Views

The quality of water in Kentucky's agricultural watersheds has received considerable attention in recent years. The main concerns in corn production areas usually center on water content of nitrate-N from commercial fertilizer and triazines from herbicide applications. Although N can be found naturally in Kentucky soils, it cannot supply all the N that corn needs to produce optimum yields. Therefore, fertilizer N is added to ensure ample nutrition. Triazines, on the other hand, do not occur naturally in the soil but are applied to the soil to effectively control weeds. Most commonly, these herbicides are applied at the time of …

Use Of Animal Wastes On Cropland, Monroe Rasnake, M. Scott Smith

Soil Science News and Views

In recent months, environmental issues relating to land application of animal and industrial wastes have been widely debated in Kentucky. On several occasions, members of the University of Kentucky Agronomy Department have been asked to provide scientific information and technical interpretation related to these complex and controversial issues. To be certain that the public and policy makers are provided with consistent and scientifically sound information, the Agronomy Department has decided to release consensus statements on some of the major agronomic issues involved. These statements reflect our best scientifically based interpretations of these important subjects. Several of our faculty with long …

No Tillage Use For Crop Production In Kentucky Counties In 1996, Gerald R. Haszler, Grant W. Thomas

Soil Science News and Views

Two years ago, we reported the status of notillage adoption in Kentucky counties in the year 1994. Now, CTIC has published the results for 1996. As before, Kentucky leads the nation in percent of crops produced under no tillage, but the percentage has increased significantly. In 1994, 44% of crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51 %. The results for both 1994 and 1996 are shown in Table 1. It is evident that Kentucky has both maintained first place and has also increased its lead over the other states. The percentage …

Pelletized Lime - How Quickly Does It React, Lloyd W. Murdock

Soil Science News and Views

Pelletized lime is made by granulating finely ground agricultural (ag) lime. It may be dolomitic or calcitic depending on the nature of the original limestone. The fine lime particles are bonded together with lignosulfonates during the pelletizing process. In general, the pelletized lime contains about 9% lignosulfonates. Pelletized limestone is a product that has been on the market for many years. The price of the material on a per ton basis is considerably higher than bulk ag lime, so its use has mainly been confined to specialty markets, with little use in production agriculture. However, the product is becoming more …

How Do Bacteria Move Through Soil?, Mark S. Coyne, J. M. Howell, R. E. Phillips

Soil Science News and Views

The contamination of water supplies by fecal bacteria is an important water quality issue in Kentucky. Contamination may come from point sources, such as straight pipes depositing raw sewage into streams, or nonpoint sources, such as manure runoff from cropland. A direct cost of contaminating water supplies is the expense that homesteads or water companies incur to chlorinate, filter, and otherwise treat water to make it potable. Indirect costs are the time lost to illness from drinking inadequately treated water, slower weight gain in livestock drinking contaminated water, and the degradation of aquatic habitats.

Detection Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Agricultural Watershed In Western Kentucky, John Potts, Larry Reber

Soil Science News and Views

The quality of water in Kentucky's agricultural watersheds has received considerable attention in recent years. The main concerns in com production areas usually center on content of nitrogen (N) from commercial fertilizer and triazines from herbicide applications in water. Although N can be found naturally in Kentucky soils, it can't supply all the N that com needs to produce optimum yields. Therefore, fertilizer N is added to ensure ample nutrition. Triazine herbicides, on the other hand, do not occur naturally in the soil but are applied to the soil to effectively control weeds. Most commonly, these herbicides are applied at …

Profitability Of Variable Rate Fertilization On A Kentucky Soil (A Theoretical Analysis), Lloyd W. Murdock, Paula L. Howe

Soil Science News and Views

Grid soil sampling and variable rate fertilizer applications are a part of the precision agriculture movement that has captured the interest of many farmers. Variable rate fertilization requires extra expense and effort plus the use of often unfamiliar technology. Global Positioning Systems (GPS) equipment and computer software are used to outline and grid the field into small manageable units or “cells” (usually 2.5 acres). Each grid cell is soil sampled and tested for pH and available nutrients. Fertilizer recommendations are made on each grid cell and the fertilizer is spread by each grid cell using a truck equipped with GPS …

How Accurate Are Uk's Nitrogen Recommendations For Corn?, Kenneth L. Wells, James E. Dollarhide, David C. Ditsch

Soil Science News and Views

Average corn yields produced on soils with high yield potential have steadily been increasing in Kentucky during the past several years. Yields from such soils in years with adequate amounts of rainfall well distributed over the growing season (May-September) may average 180 to 200 bushels per acre. A bushel of corn with crude protein content of 8 to 9% contains about 1.3 to 1.4% total nitrogen (N) on a dry matter basis. This is about 0.6 to 0.7 lbs total N per bushel of corn (at 15.5% moisture), or 108 to 126 lbs N per acre for a 180 bu/A …

Economics Of Precision Farming: Payoff In The Future, Jess Lowenberg-Beboer

Soil Science News and Views

Precision agriculture is an infant technology. This infant has some of the signs of eventual greatness, but its full capacities will not be evident for some years. Like all infants, it will require an investment of time and resources to help it to maturity. This investment will have some short term payoff, but the main benefits will be in the future.

The purpose of this presentation is to help you manage your adoption of precision farming technology for that future payoff. The specific objectives will be to:review what we have learned about the economics of precision farming, identify future benefits, …

Tillage Slows Fecal Bacteria Infiltration Through Soil, Mark S. Coyne, S. W. Mcmurry, E. Perfect

Soil Science News and Views

Bacterial pathogens can degrade ground water quality by infiltrating and eroding from land treated with poultry wastes. The potential for ground water contamination (as well as associated health risks and cost of water treatment) greatly depends on the depth of soil to the water table or bedrock and soil structure. Pathogens must move through the soil profile to contaminate ground water (although sinkholes can provide a direct channel from the soil surface to the water table in karst areas). Deep soils have less potential for contamination than shallow soils. Structureless soils retain fecal bacteria better than well structured soils. Research …

Filter Strip Length And Fecal Bacteria Trapping From Poultry Waste - An Update, Mark S. Coyne, R. A. Gilfillen, Robert L. Blevins

Soil Science News and Views

Cheap, efficient, and environmentally sound waste disposal will be needed as Kentucky's broiler industry expands. The filter strip length needed to protect water resources from contaminants in surface runoff is a pressing issue in waste management and water quality. In a previous Soil Science News and Views (Vol. 15, No. 8) we reported that grass filter strips as short as 15 feet can trap over 90% of the fecal bacteria eroding from land-applied and incorporated poultry waste during runoff following rainstorms. In this update, we provide some additional information and conclusions from that study on filter strip length, based on …

Soil Management For Intensive Grazing, Kenneth L. Wells, Charles T. Dougherty

Soil Science News and Views

Recycling of plant nutrients is of major concern in managing paddocks in pasturefields for intensive grazing. Redistribution of nutrients present in fecal and urine deposits is an important issue in growing climatically and seasonally-adapted forage species and for efficient conversion of herbage into animal products while adding to the sustainability of the system. Some of the questions that arise in managing soils for intensive grazing are discussed below.