Physical Sciences and Mathematics Commons^™

Nyssa Woods Of The Pacific-Northwest Tertiary, George F. Beck

All Faculty Scholarship for the College of the Sciences

The nyssa gums are one of the modern genera of trees most certainly present among the petrified woods and forests of the Pacific Northwest. Almost every collection from the mid-Tertiary of this region contains a few specimens of typical tupelo or sour gum. These are fine-grained woods which to the unaided eye may be mistaken for conifers.

Ancient Maples Of The Central Washington Region, George F. Beck

All Faculty Scholarship for the College of the Sciences

When I began work on the petrified logs of the general Vantage area some 13 years ago, it became apparent at once that maple-like woods are commonplace in the main (Vantage) raft forest and slightly less abundant in two rooted units of the Yakima Canyon. So widely do these woods range throughout the structural variations found in modern maples that little success has attended the efforts to assign them to nominal species. The extremes can readily be established but few hints exist as to the boundaries between them.

Two Newly Discovered Conifers, George F. Beck

All Faculty Scholarship for the College of the Sciences

Two genera of coniferous wood, apparently not listed among the Tertiary woods of the western states, have been recognized in the Percy Train collections from Rainbow Ridge, northwestern Nevada. These two, Tsuga (hemlock) and Chamaecyparis (cedar) bring up to 14 the genera of coniferous wood more or less certainly identified from the period and area in question.

Status Of Tertiary Woods Of The Western States Representing The Juglandaceae, George F. Beck

All Faculty Scholarship for the College of the Sciences

For many years there has been uncertainty concerning the generic status of some fossil leaves belonging without question to the walnut family as a whole. A review of the woods of Juglandaceae as they have appeared in Tertiary horizons of the western states has suggested which genera are present, and in what proportions their leaves (or other remains) might be expected to appear.

Nitrate Production As Affected By Grain-Crop Residues On The Surface Of The Soil, T. M. Mccalla, J. C. Russel

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The purpose of this bulletin is to present the data on nitrate contents and nitrate production in tests where straw or stalk residues were left on the surface through subsurface tillage, as compared with check treatments where these residues were plowed under or were absent. Nine of these tests were at Lincoln, Nebraska, and one was at the Hastings, Nebraska, Hydrological Project. Two tests were conducted in 1939, four in 1941, and four in 1942.

Preliminary Report On Subtratum Temperature Studies On Root Growth, Stanley W. Oexemann

Journal of the Minnesota Academy of Science

No abstract provided.

Vegetation Of The Northern Part Of Cherry County, Nebraska, William L. Tolstead

Conservation and Survey Division

Agricultural practices in the Great Plains of North America are now in a period of adjustment from a traditional agriculture initiated by pioneer farmers to a grazing economy based upon potentialities of climate and soil. The attainment of a proper system of land use has been retarded in many localities by the lack of definite information concerning the vegetation and its indicator significance. In this study of the vegetation of Cherry County, Nebraska, the interrelations between the plants and their environments are discussed, the dominant species are described, and changes in grasslands caused by seasons, grazing, and climatic cycles are …

A Proposed Method For Classifying And Evaluating Soils On The Basis Of Productivity And Use Suitabilities, Arthur Anderson, A. P. Nelson, F. A. Hayes, I. D. Wood

Nebraska Agricultural Experiment Station: Historical Research Bulletins

It is the object of this paper to present a method for classifying and evaluating the soils as mapped in regular soil surveys on the basis of land types, which are here defined as areas having reasonably similar productivity and use suitabilities. The standards used to differentiate land types will vary according to the desired objectives, but any material difference in yield, or in practices necessary to maintain a desirable level of productivity will justify recognition of land types. The proposed procedure involves a more detailed study of the influence which soils, slope, erosion, and drainage have on specific crops …

The Effect Of Cultivation On Certain Chemical And Physical Properties Of Some South Dakota Soils, Oscar E. Olson

Electronic Theses and Dissertations

Soil Nutrient losses have followed closely in the paths of advancing frontiers in agriculture. Remedies for depletion as the result of overcropping were sought by George Washington, whose interest and investigation of soil nutrient losses probably represent the earliest attention given to land exploitation in the United States, which at the present time has become a problem of national concern. Soil losses have been attributed to a number of causes , among which are cropping, erosion, leaching, burning, and rapid oxidation of organic matter in the soil. Associated with soil nutrient losses, certain significant physical and chemical changes may occur …

Spruce In The Western Miocene, George F. Beck

All Faculty Scholarship for the College of the Sciences

One of the real surprises in store for us as we began to section specimens of petrified wood from the Vantage and certain other horizons in Central Washington, was the prevalence of a spruce type hardly hinted at in the leaf lists as published for the various sediments of Yakima time (upper miocene?).

Exotic Ancient Forests Of Washington, George F. Beck

All Faculty Scholarship for the College of the Sciences

The greatest fossil forest in the world is located within easy driving distance of the University of Washington campus in the State of Washington, near the Columbia River, east of the city of Ellensburg. Mr. George F. Beck, a member of the faculty of the Ellensburg State Normal School, and a former graduate student of the College of Forestry of the University of Washington, discovered this forest, which is now known as the Ginkgo Forest State Park. Aside from its importance from a scientific point of view, this "petrified forest," which contains a greater variety of species than any other …

The Relation Of The Native Forest Cover To The Physical And Chemical Nature Of The Soils Of The Mammoth Cave National Park Area, Sheppard Walker

Masters Theses & Specialist Projects

This study was undertaken for the purpose of determining the relation existing between the native forest cover and the chemical and physical properties of the soils of the Mammoth Cave National Park area. The study was suggested by certain references in the literature to a correlation existing between forest cover and the geological, chemical and physical nature of soils of this area. The recent attempt at reforestation in the Mammoth Cave National Park area renders such a study timely, and it is believed that the results reported in this paper will materially aid the Mammoth Cave National Park Commission and …

Studies Concerning The Elimination Of Experimental Error In Comparative Crop Tests, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

It is apparent that many sources of error have unconsciously entered into comparative crop yield tests. The very important matter of overcoming variation in soil conditions as a source of experimental error has been quite extensively studied and reported by various investigators during the past decade. The means suggested for reducing such error have been (1) repetition of plats and (2) correction of yields according to check plats planted to a uniform variety or treatment at stated intervals. Both methods have proved of value and a combination of both may often be used advantageously. Some danger always exists of error …

The Storage And Use Of Soil Moisture. Report Of Experimental Substation, North Platte, Nebraska, W. W. Burr

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The profitable cultivation of the non-irrigable lands in west central and western Nebraska is limited by the amount and efficient use of the precipitation. There are tracts of land in the sand hills and minor tracts of badly worn heavier soils where the need of soil fertility is becoming evident. But, in the main, the great problem at present is not one of soil fertility, but of how to get enough water to make use of the fertility now present. The rainfall of this section, which varies from an actual shortage to seldom more than a meager sufficiency, makes it …

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.

Bulletin No. 106 - A Study Of The Production And Movement Of Nitric Nitrogen In An Irrigated Soil, Robert Stewart, J. E. Greaves

UAES Bulletins

The problem of maintaining the nitrogen content in our agricultural soils is one of vital importance to the development of a permanent system of agriculture. Any investigation, therefore, which tends to throw any light on the conditions which are necessary for maintaining the maximum supply of nitrogen in our soils needs no apology for its institution.

Bulletin No. 104 - The Storage Of Winter Precipitation In Soils, John A. Widtsoe

UAES Bulletins

It has been found that the production of one pound of dry plant substance on soils of average fertility, requires in humid districts not more than five hundred pounds of water, and in arid districts like Utah about seven hundred and fifty pounds. This indicates that the average rainfall of Utah, which is about twelve inches, if properly conserved in the soil, is sufficient to produce annually, without irrigation, from thirty to forty-five bushels of wheat to the acre, or corresponding yields of other crops. The realization of this truth has changed greatly our views of irrigation practices. The beginning …

Bulletin No. 48 - Alfalfa Or Lucern: Its Chemical Life History, John A. Widtsoe

UAES Bulletins

No abstract provided.

Bulletin No. 46 - Earthen Dams, Samuel Fortier

UAES Bulletins

According to the last census, 92 1/2 per cent of the Utah farms are irrigated. The advancement of agriculture in this State mainly depends upon the water, the available supply of which, in many of the older settled localities of the State, is already wholly utilized during the irrigation period. The future reclamation of new lands in such localities must, therefore, wait on the development of new sources of supply from storage reservoirs, sub-surface supplies, or from a more economical use of the summer flow of the available streams.

From estimates and measurements made by the hydrographers. of the United …

The Range And Distribution Of The Lower Silurian Fauna Of Minnesota With Descriptions Of Some New Species, F. W. Sardeson

Journal of the Minnesota Academy of Science

No abstract provided.

Some Notes Upon The More Recent Fossil Flora Of North Dakota And An Inquiry Into The Causes That Have Led To The Development Of The Treeless Areas Of The Northwest, John B. Leiberg

Journal of the Minnesota Academy of Science

No abstract provided.