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A Study Of The Secondary Effects Of Hill Fertilization, Horace J. Harper 2017 Iowa State College

A Study Of The Secondary Effects Of Hill Fertilization, Horace J. Harper

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

A field, laboratory, and greenhouse study of secondary effects of hill fertilization was made using several different soils as follows: Carrington loam, Webster silt loam, Grundy silt loam, Knox silt loam, Marion silt loam, and Buckner coarse sand. The effect of hill fertilization on the root development of the corn plant was also investigated.

Acid phosphate was found to have a more pronounced effect on the hydrogen ion concentration of the soil solution than either ammonium sulfate or potassium chloride. In most cases the first effect of acid phosphate was to increase the acidity of the soil solution. In poorly ...


Spatial Variability Of Subsurface Soil Conditions Causing Roadway Settlements, Ömer Bilgin, Kevin Arens, Mark Salveter, Alexander Dettloff 2017 University of Dayton

Spatial Variability Of Subsurface Soil Conditions Causing Roadway Settlements, Ömer Bilgin, Kevin Arens, Mark Salveter, Alexander Dettloff

Ömer Bilgin

Settlement of problematic soils constituting the roadway subgrade may result in pavement distress and structural failure, requiring periodic pavement patching and resurfacing. Many of these problems occur as a result of the settlement of soft cohesive and organic soils. Due to the extent of roadway projects and the limited frequency of boring locations, spatial variability of subsurface soil conditions, and sometimes due to an inadequate extent of exploration, these problematic soils may not be identified suitably during subsurface explorations. An extensive subsurface exploration program was implemented for detailed characterization of subsurface conditions for a relatively short section of an existing ...


Anchored Sheet Pile Wall Design In Expansive Soils, Ömer Bilgin, Eman Mansour 2017 University of Dayton

Anchored Sheet Pile Wall Design In Expansive Soils, Ömer Bilgin, Eman Mansour

Ömer Bilgin

Expansive soils cause damage to civil engineering structures in various parts of the world, because they swell when absorb water and shrink when dry out. Due to swelling pressures, retaining walls can be subjected to additional lateral pressures causing increased wall deformations and bending moments. Anchor forces can also increase, if the walls are anchored. When expansive soils are present behind retaining walls, swell pressures should also be considered during design in addition to the traditional lateral earth pressures. This study proposes a method to predict potential swell pressures acting on retaining walls for use in design of these walls ...


Relationships Between Hydrogen Ion, Hydroxyl Ion And Salt Concentrations And The Growth Of Seven Soil Molds, Harlan W. Johnson 2017 Iowa State College

Relationships Between Hydrogen Ion, Hydroxyl Ion And Salt Concentrations And The Growth Of Seven Soil Molds, Harlan W. Johnson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Comparatively few data have been recorded relative to the effect of hydrogen ion concentration on the development and activities of molds and other fungi, altho such records have been secured for the bacteria. For both groups much more work has been accomplished on the effect of titratable acidity. The importance of molds in transforming plant food in the soil has made advisable the securing of such data. The present paper records the results of a study of the limiting and optimum hydrogen and hydroxyl ion concentrations and the limiting concentrations of several salts as related to the growth of seven ...


The Color Of Soils In Relation To Organic Matter Content, P. E. Brown, A. M. O'Neal 2017 Iowa State College

The Color Of Soils In Relation To Organic Matter Content, P. E. Brown, A. M. O'Neal

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The color of soils has long been considered to indicate to some extent, at least, their fertility. For centuries farmers in the humid regions have been accustomed to select their land very largely on the basis of color. Dark colored soils have been preferred because experience has shown that such soils are usually more productive than light colored types. But just what the relation is between the color of soils and their fertility or crop-producing power has never been determined. It has been assumed that the organic matter or humus content, which is mainly responsible for the color of soils ...


Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali, Marcelo I. Guzman 2017 University of Kentucky

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali, Marcelo I. Guzman

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence ...


Nitrification In Acid Soils, R. E. Stepheson 2017 Iowa State College

Nitrification In Acid Soils, R. E. Stepheson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

It is quite generally believed now that nitrification may occur in acid soils, at least to some extent. The addition of lime, however, results in practically all cases in an increased activity of the nitrifying flora. This is especially true when soils are strongly acid in reaction and low in organic matter and when ammonium sulfate is used to measure nitrification.

Probably it is not merely because lime neutralizes acid soil conditions that it increases nitrification. There may be very important indirect effects of liming which are responsible for greater nitrifying action. Lime makes the soil conditions more favorable for ...


Effect Of Seasonal Conditions And Soil Treatment On Bacteria And Molds In Soil, P. E. Brown, W. V. Halversen 2017 Iowa State College

Effect Of Seasonal Conditions And Soil Treatment On Bacteria And Molds In Soil, P. E. Brown, W. V. Halversen

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The study of the microorganic population of the soil has revealed many interesting facts but none more significant nor of more far-reaching importance than the discovery that molds occur in soils and perform various functions which directly or indirectly exert considerable influence on soil fertility.

The occurrence and activities of bacteria in the soil has been the subject of extensive inquiry and much knowledge along this line has been accumulated. These organisms have been found to occur in large numbers in practically all soils and to play a prominent part in the reactions which must necessarily take place in soils ...


Effects Of Certain Alkali Salts On Ammonification, P. E. Brown, D. R. Johnson 2017 Iowa State College

Effects Of Certain Alkali Salts On Ammonification, P. E. Brown, D. R. Johnson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The occurrence of so-called" alkali spots" in certain Iowa soils has been nnted in recent publications, these spots are found only in the Wisconsin drift soil area, in association with peat deposits, and are the result of course of peculiarly poor drainage conditions. It is unnecessary here to consider further the causes of these formations or the methods which should be followed in reclaiming the areas affected as these points have been discussed in the publications referred to. It will be sufficient to call attention to the results of the chemical studies of the spots and to consider briefly some ...


Phosphorus, Potassium And Ph Management Issues Following Drought-Damaged Crops, Antonio P. Mallarino, John E. Sawyer 2017 Iowa State University

Phosphorus, Potassium And Ph Management Issues Following Drought-Damaged Crops, Antonio P. Mallarino, John E. Sawyer

John E. Sawyer

Exceptionally dry conditions this summer will result in low crop yield in much of Iowa, and weather forecasts call for normal or below normal rainfall through the fall. These dry conditions and low yields will significantly reduce phosphorus (P) and potassium (K) removal with crop harvest, and may also affect soil test P, K and pH results, complicating test interpretations.


Nitrogen Loss—Spring 2013, John E. Sawyer 2017 Iowa State University

Nitrogen Loss—Spring 2013, John E. Sawyer

John E. Sawyer

Dry soils across Iowa from deficit precipitation following the drought in 2012 have changed to excess wetness this spring. Unfortunately, precipitation to replenish subsoil moisture has been much more than needed. As I wrote in an ICM News article earlier this spring, one downside to the excess precipitation has been movement of carryover nitrate deeper into the profile and to tile lines, resulting in high nitrate-N concentrations in surface waters. This means there is less nitrate-N carryover to be utilized by 2013 crops, although as noted in the previous article, not all of the carryover N moved below the three-foot ...


Effect Of Sulfur And Manure On Availability Of Rock Phosphate In Soil, P. E. Brown, A. R. Gwinn 2017 Iowa State College

Effect Of Sulfur And Manure On Availability Of Rock Phosphate In Soil, P. E. Brown, A. R. Gwinn

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The use of phosphorus fertilizers is now a recognized necessity in all systems of permanent agriculture. However well supplied naturally, all soils gradually become depleted in phosphorous thru the removal of crops and this element must be returned if crop production is to continue satisfactory. Many soils, especially those under long continued cultivation, have been found to respond very profitably to phosphorus fertilization while even the newer, more fertile soils are approaching a condition where phosphorus will soon become the controlling factor of growth. The interest in phosphorus fertilizers is therefore becoming more widespread and the use of these materials ...


Carbon Dioxide Production In Soils And Carbon And Nitrogen Changes In Soils Variously Treated, R. S. Potter, R. S. Snyder 2017 Iowa State College

Carbon Dioxide Production In Soils And Carbon And Nitrogen Changes In Soils Variously Treated, R. S. Potter, R. S. Snyder

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The carbon dioxide of the soil atmosphere, along with the water, has long been recognized as the most active agent in the decomposition of comparatively inert minerals to give available and soluble plant food material. It is probable that herein lies the great benefit which comes from the application to soil of organic material which not only increases the energy material easily available for the bacteria, but also improves the physical condition of the soil. This in turn increases bacterial activity, which gives rise to increased carbon dioxide production.

At the Iowa Agricultural Experiment Station, for some time past, both ...


Influence Of Humus Forming Materials Of Different Nitrogen-Carbon Ratios On Bacterial Activities, P. E. Brown, F. E. Allison 2017 Iowa State College

Influence Of Humus Forming Materials Of Different Nitrogen-Carbon Ratios On Bacterial Activities, P. E. Brown, F. E. Allison

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The determination of the nitrogen-carbon ratio in soils is now considered of much importance in fertility studies. Not only does it show the organic matter content of soils more accurately than the more or less arbitrary humus determinations, concerning which considerable difference of opinion exists, but it also throws some light on the rate at which decomposition processes are occurring.


The Effect Of Some Manganese Salts On Ammonification And Nitrification, P. E. Brown, G. A. Minges 2017 Iowa State College

The Effect Of Some Manganese Salts On Ammonification And Nitrification, P. E. Brown, G. A. Minges

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Manganese occurs in practically all soils, but the quantities present are exceedingly variable. Twenty-six typical soils analyzed by Robinson showed the presence of manganese in amounts varying from 0.01 to 0.51 per cent of MnO. Other studies have shown the occurrence of very large amounts in certain soils, but the average of 0.071 per cent MnO given in the work referred to above probably represents fairly accurately the manganese content of normal soils in this country.


Studies In Sulfofication, P. E. Brown, H. W. Johnson 2017 Iowa State College

Studies In Sulfofication, P. E. Brown, H. W. Johnson

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Recent experiments have shown that sulfofication or sulfuroxidation is an important process occurring in field soils. Plants have been found to require considerable amounts of sulfates for their best growth and inasmuch as sulfur is not present in soils in that form, but as unassimilable organic and inorganic compounds, the sulfur-feeding of crops will depend very largely upon the ability of a soil on which they grow to produce sulfates from these unavailable substances. In other words, the total sulfur content of a soil, alone, will not show the sulfur available for plant growth. The sulfofying power of the soil ...


Bacterial Activities And Crop Production, Percy Edgar Brown 2017 Iowa State College

Bacterial Activities And Crop Production, Percy Edgar Brown

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Until the present time studies in soil bacteriology have dealt almost exclusively with the occurrence and activities of microorganisms in the soil and no attempt has been made to interpret experimental results from the standpoint of crop production. This is due, of course, to the fact that as a science soil bacteriology is scarcely out of its infancy and the preliminary investigations in any science must of necessity deal mainly with underlying principles and such studies are always apt to be rather fragmentary in character.


Determination Of Amino Acids And Nitrates In Soils: Amino Acids, Ammonia And Nitrates In Manured And Limed Soil, R. S. Potter, R. S. Snyder 2017 Iowa State College

Determination Of Amino Acids And Nitrates In Soils: Amino Acids, Ammonia And Nitrates In Manured And Limed Soil, R. S. Potter, R. S. Snyder

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

In view of the fact that no data had ever been obtained on the quantitative relationships of the organic material in the soil by such methods as would preclude a chemical transformation, two things seemed desirable, in continuing the humus investigations at the Iowa Agricultural Experiment Station. First, to attempt the analysis of the organic material of the soil without subjecting it to hydrolysis or other chemical change, and second, to correlate the proportionate quantities of the compounds or classes of compounds found with the kind of soil, its history, treatment, fertility, etc.


Sulfofication In Soils, P. E. Brown, E. H. Kellogg 2017 Iowa State College

Sulfofication In Soils, P. E. Brown, E. H. Kellogg

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

Sulfur has long been known to be one of the essential plant food constituents. It has always been believed, however, that there was sufficient present in all soils for the optimum growth of crops. This assumption has been very largely based on Wolff's analyses of the ashes of various crops which showed the presence of very small amounts of sulfur.

The recent work of many investigators has demonstrated, however, that the amount of sulfur in plant materials as determined in the ash is, in most cases, entirely too low; that there is a considerable loss of sulfur in the ...


Bacteriological Studies Of Field Soils, Iii. The Effects Of Barnyard Manure, Percy Edgar Brown 2017 Iowa State College

Bacteriological Studies Of Field Soils, Iii. The Effects Of Barnyard Manure, Percy Edgar Brown

Research Bulletin (Iowa Agriculture and Home Economics Experiment Station)

The conclusions which may be drawn from the experiments upon the effects of barnyard manure on bacteriological activities of field S'oils presented in this bulletin are as follows:

1. Applications of manure up to sixteen tons per acre increased the numbers of organisms in the soil as shown by the growth on modified synthetic and albumen agar. The ammonifying power of the soil as shown by tests with the casein-fresh soil, albumen-fresh soil, dried blood-fresh soil, and dried blood-air-dried soil methods, and the nitrifying power tested by the ammonium sulfate-fresh soil, and the ammonium sulfate-air- dried soil methods were ...


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