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Articles 13801 - 13821 of 13821

Full-Text Articles in Physical Sciences and Mathematics

The Effect Of Cultivation On Certain Chemical And Physical Properties Of Some South Dakota Soils, Oscar E. Olson Jan 1937

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 Nov 1936

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 Apr 1935

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 Aug 1933

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 …


Bulletin 115 - The Value Of Windmills For Pumping Water In Western Australia, A. H. Scott Jan 1923

Bulletin 115 - The Value Of Windmills For Pumping Water In Western Australia, A. H. Scott

Bulletins 1 - 2999

It is surprising to note the dearth of up-to-date reliable information dealing with actual results of modern windmills, under working conditions, though literature on thousands of other subjects less important can usually be obtained.

In this bulletin there is presented a complete and accurate record of the amount of water pumped daily by a windmill, under actual working conditions, for a period of 14 months.


Bulletin No 81 - The Improvement Of Pastures With Notes On The Pasture Trefoils In Western Australia, E. A. Mann, D. A. Herbert Jan 1920

Bulletin No 81 - The Improvement Of Pastures With Notes On The Pasture Trefoils In Western Australia, E. A. Mann, D. A. Herbert

Bulletins 1 - 2999

Agriculture can be roughly divided for practical purposes into two large divisions, those of animal husbandry and vegetable husbandry. It is with the former that this pamphlet is chiefly concerned and its object is to contribute, it possible, in some small measure towards the problem of how to increase time stock carrying capacity of our natural pasture lands. it is unnecessary to dwell upon the importance of this question, especially in relation to the remarkable developments which are taking place in time wool-growing industry in the Southern and more coastal areas of Western Australia.


Studies Concerning The Elimination Of Experimental Error In Comparative Crop Tests, T. A. Kiesselbach Jun 1918

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 Jul 1914

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 Aug 1910

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 32 - Noxious Weeds And Poison Plants, Department Of Agriculture, Western Australia Jan 1910

Bulletin No 32 - Noxious Weeds And Poison Plants, Department Of Agriculture, Western Australia

Bulletins 1 - 2999

Many settlers, new to this State, find some difficulty in distinguishing those vegetable pests which are classed as noxious weeds, the eradication of which is made compulsory under the Noxious Weeds Act of 1904.

In order to facilitate the ready recognition of the plants which are the least familiar, the Department of Agriculture has prepared this Bulletin, giving illustrations of the several varieties which have been gazetted as noxious. these are: - Stinkwort, Bathurst Burr, Noogoorn Burr, Nut Bramble, Spanish Radish, Prickly Pear, Apple of Sodom, sweet Briar, Wild Bramble, Star Thistle (purple), Double Gee and Water hyacinth.


Bulletin No. 106 - A Study Of The Production And Movement Of Nitric Nitrogen In An Irrigated Soil, Robert Stewart, J. E. Greaves Dec 1909

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 Oct 1908

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 …


Irrigation Farming: A Handbook For The Proper Application Of Water In The Production Of Crops, Lucius M. Wilcox Jan 1907

Irrigation Farming: A Handbook For The Proper Application Of Water In The Production Of Crops, Lucius M. Wilcox

University of Nebraska-Lincoln Extension: Historical Materials

A handbook for the application of water in the production of crops.


The Effect Of Certain Methods Of Soil Treatment Upon The Corn Crop, T. L. Lyon Jun 1898

The Effect Of Certain Methods Of Soil Treatment Upon The Corn Crop, T. L. Lyon

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The effect of certain methods of soil treatment upon the corn crop in Nebraska.


Bulletin No. 48 - Alfalfa Or Lucern: Its Chemical Life History, John A. Widtsoe Mar 1897

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 Nov 1896

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 Rainfall Of Nebraska, G. D. Swezey, George A. Loveland Jun 1896

The Rainfall Of Nebraska, G. D. Swezey, George A. Loveland

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Covers the rainfall in Nebraska with respect to farming.

Includes:

Character of the precipitation

Amount of precipitation

Rainfall of the growing season

Number of rainy days

Variability of rainfall

Progressive changes in the rainfall

Monthly precipitation of all stations and locations in Nebraska from the earliest years to 1895

Average precipitation for Nebraska from the earliest years through 1895

Charts of normal precipitation--weekly, monthly, and annual


The Conservation Of Soil Moisture By Means Of Subsoil Plowing, T. L. Lyon Sep 1895

The Conservation Of Soil Moisture By Means Of Subsoil Plowing, T. L. Lyon

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Covers the conservation of soil moisture by means of subsoil plowing.


Water Supply In Nebraska, O. V. P. Stout Feb 1895

Water Supply In Nebraska, O. V. P. Stout

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Covers the water supply and irrigation with respect to farming in Nebraska in 1894.


The Range And Distribution Of The Lower Silurian Fauna Of Minnesota With Descriptions Of Some New Species, F. W. Sardeson Jan 1890

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 Jan 1886

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.