Date of Award:

5-1949

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Wildland Resources

Department name when degree awarded

Range Management

Committee Chair(s)

L. A. Stoddart

Committee

L. A. Stoddart

Committee

C. W. Cook

Abstract

A great deal has been accomplished in developing methods of restoring abused lands through seeding, yet there is much to be desired in refinement of techniques and in substantiation of previous experimental results. Controversial opinions as to the best season of planting indicate that additional trials are needed. New species need to be introduced, developed, and proved. Methods are needed which lead to more efficient utilization of those factors limiting the degree of success in establishment. Since moisture is the most predominant limiting factor throughout the arid and semi-arid range land, special attention is given to more efficient utilization of the precipitation.

There are three fundamental ways of increasing or making the most of the available water supply: (1) increasing the absorption of water by the soil, (2) storing moisture in the soil one year for use the next, and (3) preventing undue withdrawal of water. Tillage and prevention of runoff are means of increasing the absorption of water by the soil, and moisture may be stored in the soil by leaving it fallow during a growing season. Moisture losses from the soil can be partially controlled by reducing evaporation from the soil surface--as by maintaining a soil cover of mulch or stubble, and by reducing transpiration losses--as by killing all weeds.

In reducing competition and transpiration losses, an important aspect is the density of seeded species during the initial stages of establishment. A slight change in the amount of available water, or in the efficiency of its use, can bring about success instead of failure. Easily observed treatment differences are best obtained when the supply of available moisture is near the critical point. During the seasons of plentiful or short supply, differences may not be observed.

Because of the above, a study was made involving 3 recently introduced species of Agropyron--intermediate wheatgrass (Agropyron intermedium), stiff-hair wheatgrass (A. trichophorum), and tall wheatgrass (A. elongatum). Performance of each is compared to that of crested wheatgrass (A. cristatum). The species were seeded on adjacent plots, measuring 20 by 50 feet, in all combinations of the following: 2 seasons of planting, 3 intensities of seeding, and 3 spacings between drill rows.

Checksum

eefb07ca360b1b115e8d5fdb258ad428

Download

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .