Soil Science Commons^™

Quality Of Legume Inoculants In Kentucky, M. Scott Smith

Soil Science News and Views

Successful and profitable production of legumes requires nodulation by Rhizobium bacteria which supply the crop with fixed N. The appropriate strains of bacteria are often absent from soils, since they do not persist without a suitable host plant. Under these conditions, that is when the specific legume crop has not been planted in the field for more than 3 or 4 years, it is necessary to inoculate the seed (or sometimes the soil) with Rhizobium.

Effect Of Fertilizer Salts On Crop Production, V. P. Evangelou

Soil Science News and Views

Soil consists largely of mineral and organic matter, air, and water. Plants obtain nutrients from mineral and organic matter, oxygen from air, and they use water as a carrier of nutrients from the soil into the root and to the above ground portion of plants.

Since soil water functions as a carrier of nutrients from solid fractions of soil into and through plants, it plays a very important role in plant nutrition. Because of this importance, correct chemical balance of the soil solution is necessary for best crop performance. This means that pH of the solution should be in the …

Seedbed Preparation For Pasture Renovation, Harold B. Rice

Soil Science News and Views

In Kentucky renovation has come to mean the re-establishment of legumes in grass pastures and meadows. Many acres of grassland do not contain enough legumes to fill the amount of nitrogen needed and to improve the nutritional value of the forage. A good stand of white clover, for example, has the capacity to fix about 100 pounds of nitrogen per acre. Because of this, pastures containing around 40 percent clover can produce about as much meat or milk as grass pastures fertilized with 150 pounds of nitrogen per acre. For best results in seeding clovers into grass sods, fields should …

Energy Conservation In Corn Production, Wilbur W. Frye

Soil Science News and Views

On-farm production of food and fiber uses about 3% of the annual U.S. energy consumption. About one-third of this energy is directly from fossil fuels used in farm tractors and trucks and for crop drying, while about one-fourth is used in manufacturing and transporting fertilizers. Tillage and N fertilizers are the two largest uses of energy in non-irrigated product ion of crops which are not dried artificially. Thus, the greatest effects of energy conservation can be achieved in these two areas.

Does No-Till Change Soil Management Practices?, Robert L. Blevins

Soil Science News and Views

Successful no-tilling requires a different approach to soil management practices. Since continuous no-tillage systems leave residues on the soil surface without mechanically mixing them into the plow layer and since lime and fertilizer are surface-applied, no-tilled soils have biological, chemical and physical properties contrasting with those of a plowed soil. For any crop production system to be widely accepted and used it must provide and maintain desirable physical properties of the soil, control erosion and replace nutrients removed by crops and other losses. This can be accomplished in a no-till system if proper management is used.

Soil Ph: What It Is, How It Is Measured, Why It Is Important, John H. Grove

Soil Science News and Views

Soil pH is related to the hydrogen ion (H⁺) activity of the soil-water system. The chemical definition of pH is as follows: pH=-log (H⁺). In other words, for a pH drop of 1 unit (e. g. from pH 6 to pH 5) there will be a ten~fold increase in H⁺ activity in the soil solution. If pH 1 rises by 1 unit, only one-tenth as much acidity will be present in solution. As such, pH is only a measure of the active acidity in the soil water solution bathing plant roots. This fraction of total …

Liming Tobacco Soils, J. L. Sims

Soil Science News and Views

Control of soil acidity by liming is very important in successful tobacco culture. Adding lime to an acid soil increases the availability of nearly all plant nutrient elements, increases the efficiency of added fertilizers, and prevents the toxic effects of high concentrations of soluble aluminum, manganese, and iron. It is a natural tendency for most Kentucky soils to become acid with time due to losses of bases (calcium, magnesium, potassium, and sodium) from soil by rainfall, However, tobacco soils possess certain unique problems that warrant careful monitoring of soil pH every two to three years.

Fall Fertilization Programs, William O. Thom

Soil Science News and Views

Achieving recommended fertility levels for the next season's crop is important enough that it should not be subject to all the uncertainties of spring weather. Fall offers more time for careful planning of fertilizer and lime requirements based on good soil tests. Fields are generally in good condition to support application equipment without creating excessive soil compaction.

Seasonal And Yearly Fluctuations Of Soil Tests, Lloyd W. Murdock

Soil Science News and Views

One of the most important management tasks of a good farmer is taking a good soil sample. The recommendations based on these samples will help determine yield and profitability. A number of factors have an effect on the soil test results.

Fertilization Of Double-Crop Soybeans, Grant W. Thomas

Soil Science News and Views

The improvement of minimum-and no-tillage methods has helped increase the double-cropped acreage of soybeans in Kentucky to about 700,000 acres. Similar increases have been observed in our neighboring states. Most double-cropped soybeans in Kentucky follow winter wheat harvested for grain. Thus, they are at a disadvantage if the wheat leaves the soybean crop with a nutrient-deficient soil.

Use Of Molybdenum For Soybean Production, Monroe Rasnake

Soil Science News and Views

Molybdenum (Mo) is a micronutrient that is required by soybeans in very small amounts. As little as 0.5 parts per million of Mo in soybean tissue is sufficient for normal growth. Compare this with a phosphorus sufficiency level of about 2,000 parts per million. However, even though only small amounts are needed, a Mo deficiency can drastically reduce yields of soybeans.

Nitrogen Value From Plowing A Sod, M. Scott Smith

Soil Science News and Views

With economic conditions as they are, crop producers need to effectively use all the resources available to them. To help offset high N fertilizer prices, one resource that may be used to significantly reduce production costs is the organic N accumulated in and on soils. When crops are planted into a tilled sod the requirement for added N fertilizer will usually be less than on land previously in row crops. The following discussion considers the processes and factors determining the quantity and availability of N in a sod, and offers some guidelines for estimating the N value of a sod.

Band Vs. Broadcast Application Of Fertilizer, Kenneth L. Wells

Soil Science News and Views

Current fertilizer prices coupled with other increased production costs have renewed interest in band applications of fertilizer as a means of lowering fertilizer costs while maintaining crop yields. Fortunately, much basic soil fertilizer research has been conducted over the years which provides an understanding of the relative merits of band and broadcast placement. The following discussion outlines the basic considerations involved in deciding which of these two placement methods may be more economically useful for specific crop production systems. To better understand these considerations, certain principles related to adding fertilizer to the soil should be kept in mind. These are …

Liming Needs Of Kentucky Soils, William O. Thom

Soil Science News and Views

A sound liming program is the first step in building and maintaining soil fertility. Lime lowers the acidity (raises pH) of soil and prevents the adverse effects of high concentrations of soluble aluminum, iron, and manganese on crop growth--effects often associated with acid soils. Maintaining a suitable pH assures adequate levels of calcium and magnesium. Liming an acid soil increases the availability of most essential plant nutrients, increases the efficiency of fertilizers, improves the effectiveness of some herbicides, and makes beneficial soil organisms more active.

Molybdenum Nutrition Of Crops In Kentucky, J. L. Sims

Soil Science News and Views

Molybdenum (Mo) is one of eight micronutrient elements required for the growth of plants. Research conducted in California nearly 40 years ago established its need for plant growth. Mo deficiencies have been reported throughout the world, especially on acid soils in the United States, Australia, and New Zealand. Generally, the Mo requirement of leguminous crops is greater than for non~legumes, but many non-leguminous field and vegetable crops have responded to additions of fertilizer Mo under severe deficiency conditions. Of all the nutrient elements required by plants for growth, Mo is needed in smallest amounts.

Use Of Magnesium (Mg) For Crop Production In Kentucky, John H. Grove

Soil Science News and Views

Magnesium (Mg) is an important element in the nutrition of plants and animals, although it has long been considered a "secondary" nutrient for plants. Nitrogen (N), phosphorus (P), and potassium (K) are "primary'' nutrients and are usually given the greatest consideration in crop fertility programs. However, as yield levels have risen, more attention has been directed towards Mg and other nutrient elements. Concern about hypomagnesemia (grass tetany) in ruminants (cattle, sheep) has led to particular concern about soil and plant Mg levels.

Nitrification Inhibitors, Wilbur Frye

Soil Science News and Views

Nitrogen often limits the production of nonlegume crops because of inefficiency of N fertilizers. In some cases, more than half the fertilizer N may be lost from the soil. Therefore, it is important to use it as efficiently as possible. One way in which N fertilizer efficiency may be improved is by slowing the nitrification process in the soil.

Cover Crops And Crop Residues, Robert L. Blevins

Soil Science News and Views

In Kentucky, erosion hazard is by far the major limitation for use of cropland. It has been estimated that about 11.4 million acres are subject to erosion hazards. This means that approximately 75% of the soils potentially suited for cropland is sloping enough that risk of erosion is the greatest limitation in its use for crop production. Probably the greatest risk of erosion results from leaving row-cropped fields unprotected over winter. The use of cover crops and proper management of crop residues to stablize these soils during the winter months are relatively inexpensive agronomic practices that are very effective in …

Soil Surveys In Kentucky, Harry Hudson Bailey

Soil Science News and Views

Fifty-four Kentucky counties have modern soil surveys (published 1959, or later) using the mapping and soil classification procedures of the National Cooperative Soil Survey. The cooperators in the program include the USDA-SCS, USDA-FS, Kentucky Department for Natural Resources and Environmental Protection and the Kentucky Agricultural Experiment Station.

The Status Of Sulfur Fertilization Of Crops In Kentucky, Lloyd W. Murdock

Soil Science News and Views

Sulfur has long been recognized as being essential for the growth of plants and animals due to it being necessary for production of several amino acids. Although regarded as a "secondary" element, it is required by plants in fairly high amounts, very similar to that of phosphorus. Sulfur deficiency symptoms in plants are somewhat similar to those of nitrogen since an overall uniform pale-green leaf color develops. Sulfur deficiencies are often found in crops growing on sandy soils with low organic matter content.

Use Of Plant Analysis, William O. Thom

Soil Science News and Views

Plant analysis is the laboratory determination of several nutrient elements on a single sample of plant material. In recent years this technique has been more frequently used to diagnose soil fertility problems 0r to monitor soil fertility recommendations on growing crops. Current instrumentation makes it possible to rapidly determine several elements on an extract from a plant sample.

Influence Of Soil Type On Nitrogen Fertilization Of Corn, Grant W. Thomas

Soil Science News and Views

In Kentucky, response of corn to nitrogen fertilizer is influenced strongly by soil characteristics. These soil properties are of both a permanent and temporary nature.

Fertilizing Soybeans, Monroe Rasnake

Soil Science News and Views

Soybeans need a fertile soil with a pH of about 6.4 for maximum production. This condition is best attained through a regular soil testing and fertilization program. A fertility program based on fertilizer and lime. use as determined by soil testing is more economical and more effective than applying large amounts of fertilizer at planting. Soil testing is the key.

Fluid Fertilizers, Kenneth L. Wells

Soil Science News and Views

Fluid fertilizers are available in a wide range of products to Kentucky farmers. Although the term "liquid fertilizer" is commonly used to describe all fluid fertilizers, in reality the two terms do not imply the exact same meaning. Technically, all fertilizers of fluid consistency which can be transferred by pump are called "fluid f ertilizers11. This is the proper term to use in the broadest sense to describe such materials. There are two general types of fluid fertilizers. One group is called "suspensions" or "slurries", and the other group is referred to as "clear liquids".

Water Relationships Of Kentucky Soils, Ronald E. Phillips, Grant W. Thomas

Soil Science News and Views

Plant water stress is the most limiting single factor in crop production in Kentucky. It almost always occurs sometime during July and/or August even though it's variability makes it hard to predict. Even though the 1979 growing season was an exception to this generalization the 1980 growing season was a vivid reminder of this fact especially in Western Kentucky.

Field Preparation For Pasture Renovation, Harold B. Rice

Soil Science News and Views

Grassland renovation is the improvement of pasture and hay fields by partial destruction of the sod, plus liming, fertilizing, and seeding as may be required to establish or re-establish desirable forage plants without an intervening crop. In Kentucky, this improvement has been primarily through the seeding of legumes such as clovers and alfalfa into grass sods.

Since liming and fertilizing are essential steps in pasture renovation the FIRST step is to have your soil tested to determine how much lime and plant nutrients to apply. Seedbed preparation will range from none to complete disturbance of the existing sod depending on …

Fertilizer Recommendations, William O. Thom

Soil Science News and Views

Fertilizer recommendations are interpreted from a soil test value. The interpretations are based on field research that compares crop yield to soil test levels and the amount of fertilizer applied. These field studies provide data to compare relative yield of a crop for a measured soil test value and fertilizer recommendations are then calibrated to these soil test values.

Soil Drainage---Effects On Crop Production, Kenneth L. Wells

Soil Science News and Views

One of the major physical properties of soil which is important to crop production is drainage through the rooting zone. This characteristic greatly influences aeration in the rooting zone, and the degree of aeration greatly influences several important biochemical reactions of economic importance to crop production.

Conservation Tillage Practices, Monroe Rasnake

Soil Science News and Views

The loss of topsoil from farmlands has become a serious problem in some parts of Kentucky. During the past 20 years, grain crop acreage has tripled. The production of soybeans, which leaves the soil in a condition more susceptible to erosion, has grown from almost none to 1.7 million acres. Much of this increased acreage has come at the expense of soil conserving crops such as hay and pasture on sloping class II and III land with an erosion hazard. Use of large equipment, larger fields, chemical weed control, etc., has added to the scope of the problem with which …

Use Of Annual Legumes As Winter Cover For No-Till Corn, Robert L. Blevins

Soil Science News and Views

Legumes in crop rotations hsve traditionally provided nitrogen for nonlegume crops since the early history of agriculture. When in association with the proper strains of Rhyzobium bacteria, legumes are capable of fixing atmospheric nitrogen, which when residues from the legumes decompose, enrich the soil content of nitrogen. Legume cover crops recycle other nutrients, thus reducing leaching losses that often occur in soils during the winter and spring seasons. In addition to these advantages, legume cover crops used with no-tillage corn provide a surface mulch which reduces soil erosion, slows evaporation of soil moisture, increases infiltration of rainfall, and increases soil …