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.

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.

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.

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 …

Delayed Nitrogen Applications On Corn, Grant W. Thomas

Soil Science News and Views

A method of fertilizer application that was standard practice 30 to 50 years ago has become important once again, and for the same reason. When nitrogen fertilizer was expensive and corn was cheap, it was considered prudent to save back some of the nitrogen fertilizer and apply it when the corn was "knee-high." This was thought to be safer because some of the nitrogen added at planting might be lost before the corn was big enough to take advantage of it. The increasing cost of nitrogen fertilizer has made efficient use of this product important again.

Effects Of No-Tillage Fallow As Compared To Conventional Tillage In A Wheat-Fallow System, C. R. Fenster, G. A. Peterson

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The benefits of reducing tillage by use of herbicides for weed control emphasizes why research was started to study a fallow system where all tillage was replaced by herbicides. Wheat planting was then the only soil disturbing operation. Objectives of the research were to compare the effects of no-tillage (chemical), stubble-mulch and plow (bare fallow) systems of fallow on: 1. Grain yield. 2. Grain protein. 3. Residue retention. 4. Soil nitrate-nitrogen accumulation. 5. Soil water accumulations during fallow. Data presented are in the form of a progress report. These experiments will continue.

An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This experiment was designed to measure in situ concentrations of NH₄⁺ and NO₃^--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH₄⁺-N.

The extractable NH₄⁺-N concentration was approximately 40 μg/g in the 0₁ horizon and 10 μg/g in the 0₂ horizon. The NO₃^--N concentration was approximately 5 μg/g in the 0¹ horizon and 4 μg/g in the 0_{2 …}

The Effect Of Alternate Wetting And Drying On The Ammonium And Nitrite Nitrogen Transformation In Soils, Virupax C. Baligar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations were carried out to study the effect of alternate wetting and drying cycles on the mineralization, nitrification, and denitrification of soil nitrogen in two soils, in the presence or absence of added ammonium and nitrite. Soils were analyzed at the end of each drying cycle for total inorganic nitrogen, ammonium, and nitrite nitrogen. Gaseous products, i.e., ammonia, and the oxides of nitrogen (NO and NO₂) were collected in the course of drying for determination.

The drying cycles accelerated the rate of nitrogen mineralization in both soils and further increased the oxidation of applied and available ammonium. The …

The Influence Of Organic Matter And Ph On Transformations Of Nitrites To Elemental Nitrogen, Mohammad A. Rashid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen occupies an important and prominent place in plant and animal nutrition. Large quantities are required by plants and must be available in the soil. Recently the use of nitrogenous fertilizers has increased manyfold. In view of the importance of this element in crop production, even greater use is anticipated in the coming years. In order to make full use of the applied nitrogen, continued investigations of soil-nitrogen relationship are imperative; however, this element presents many complex and challenging problems to investigators.

Nitrite Reactions In Soil, John Otto Reuss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Losses of soil nitrogen that cannot be attributed to leaching or crop removal have been observed in many field experiments. Several mechanisms have been proposed to account for these losses.

Moisture And Temperature Effects On The Transformations Of Nitrogen From Applied Ammonium Sulfate In A Calcareous Soil, John Keith Justice

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen has commonly been a deficient element in the cultivated soils of the world since the beginning of agriculture. The general acceptance of the practice of using manures as a means of increasing plant growth, as shown by the records of ancient civilizations, attest to this fact. Since the time of von Liebig there has been an increasing awareness of the importance of this deficiency in soils. As a result of a better understanding of the problem and the increasing availability of commercial forms of nitrogen, a rapid increase in the use of nitrogen fertilizers has taken place in the …

Development And Evaluation Of Laboratory Methods For Determining The Nitrogen Supplying Power Of The Irrigated Soils Of Northern Utah, Jerald Ross Wight

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is the most widely needed and the most widely used of the fertilizer elements. Yet, in spite of the voluminous research work of evaluating the nitrogen status of soils, laboratory tests for the purpose of predicting need of nitrogen fertilizer are not very widely used. In general, laboratory tests for nitrogen supplying power have not given satisfactory results. Methods currently employed by a few laboratories can be classified either as biological or chemical. In the former method, the soil is incubated under optimum conditions and the amount of nitrate released over a given period of time is measured and …

Bulletin No. 109 - The Nitrogen And Humus Problem In Dry-Land Farming, Robert Stewart

UAES Bulletins

The effect of cultivation and the growth of crops upon the nitrogen and humus content of soils has been studied by various investigators, both in America and Europe. In general, the results of the various investigations indicate that cropping and cultivation are very destructive of the organic. matter and the nitrogen of the surface soil.