Revegetation of Eroded Lands in the High Plains and Rolling Plains of Texas and Oklahoma

THE revegetating of eroded croplands constitutes a major phase of the coordinated soil and moisture conservation program in the high and rolling plains of Texas and Oklahoma which comprise some 55 million acres in the northwestern portion of the two states. Thousands of acres of land in the area are not suited for cultivation and should be returned to a cover of grass if a permanent agriculture is to be maintained. These areas are not adapted for cultivation because of soil characteristics or topography. Typical examples are deep shifting sands, shallow soils, and steep eroded areas. Annual rainfall varies from approximately 15 to 30 inches. Seasonal distribution is usually favorable for the establishment of grasses. Wind and water erosion are both common, wind erosion being more prevalent on the high plains, and water erosion on the rolling plains. The absolute necessity for reestablishing a protective cover was dramatically, as well as tragically demonstrated during the "dirty thirties" or "dust bowl" years. Some revegetation work had been done prior to that time, but only on a very small scale.The Southern Great Plains Agricultural Council assumed a very active interest and leadership in the revegetation problem. A revegetation subcommittee was formed' and trial plantings initiated. The methods used in these first field trials were based largely upon techniques that had been developed at the Woodward, Okla., and Hays, Kans., experiment stations, ,and at the Soil, Conservation Service Research Experiment Station at Amarillo, Tex. The field trials were carried out primarily by Soil Conservation Service operations and research personnel, with the close cooperation of both federal and state experiment stations. Many of the initial trials were failures; however,' enough were successful to point the way toward the proper ways and means of grass establishment. Careful records were kept of both the failures and the successes. It was recognized early that the amount and seasonal distribution of rainfall was the most important single factor in obtaining successful stands of grass. Table i shows the results that were obtained from 64 field trials made in 1941, 1942, and 1943. These results show the effect of the .abnormally high rainfall in 1941 on stand establishment and the resultant higher percentage of failures with the lower rainfall in 1942 and 1943; also that grass stands can become well established with normal or below normal rainfall after the first growing season. This early work included a comparison of the • effectiveness of various tillage methods and cover crops for the stabilizing of lands to be revegetated and for providing noncompetitive cover in which-to seed grasses. It also included the. evaluation of species, mixtures, seeding rates, dates, and methods of seeding (i, 2). Experience on the experiment stations, Soil Conservation Service demonstration projects and nurseries, and on the farms and ranches of soil conservation district cooperators during the past 10 years has resulted in the development of sound methods and techniques for the successful establishment of grass (i. . 3)Revegetation work has progressed to where more than 80% of the seedings are successful, and thousands of acres are being established to grass annually. The adapted grasses and planting methods will of course vary somewhat over such an extensive area. However, past experience has proved the following procedures for revegetation to be sound: