The purpose of this study was to analyze the interrelationships of the Willa Cather Memorial Prairie in terms of the characterizing species and types of vegetation. At each of 100 sample stand locations data were obtained on the 244-ha prairie in Webster County, Nebraska, to estimate percent basal cover and percent species composition. Estimates were analyzed quantitatively with the aid of vegetation ordination techniques, from which 15 vegetation types were discerned. Of the 15 types, two accounted for over 40% of the stands: a Kentucky bluegrass (Poa pratensis)-buffalograss (Buchloe dactyloides)-blue grama (Bouteloua gracilis)-type and a Kentucky bluegrass-sideoats grama (Bouteloua curtipendula)-big bluestem (Andropogon gerardi) type. Two secondary types accounted for another 16% of the stands, while the remaining 44% of the stands were fairly evenly dispersed within nine other types. Uplands were predominately Kentucky bluegrass, buffalograss, blue grama, and Japanese brome. Sideoats grama, little bluestem (Andropogon scoparius), and Kentucky bluegrass dominated hillside stands. Most abundant in lowlands were Kentucky bluegrass, sideoats grama, Japanese brome, and big bluestem. Due to the abundance of Kentucky bluegrass, late spring burning was prescribed to improve the condition and productivity of the prairie.

The application of N fertilizer to crested wheatgrass on a dry rangeland site increased yields substantially. In the early part of the growing season when moisture was not limiting, soil moisture was withdrawn from the fertilized site at a higher rate than from the unfertilized plots. At later periods in the growing season the soil water potential curves paralleled each other with the fertilized crop growing under conditions of lower soil water potential. The decreased soil water potential was confirmed when the actual evapotranspiration, as measured by the energy balance method, was examined. The data indicate that for a period following rapid growth in the spring, the evapotranspiration of the fertilized block was less than that of the unfertilized. The soil water potential data indicate that seasonal evapotranspiration was slightly higher on the fertilized plot than on the unfertilized. The water use efficiency, in terms of biomass produced per unit of water used, was much greater for fertilized crested wheatgrass and resulted in increased yields.

Sixteen mixed breed sheep, 1-2 years old and fitted with esophageal fistulas, were allotted at random to four range pastures in southeastern South Dakota. Two of the pastures (4.9 and 5.3 ha) were treated with 67.2 kg of N, 33.6 kg of P, and 89.7 of K/ha, whereas the other two pastures (6.9 and 7.3 ha) received no fertilizer treatment. Esophageal extruded samples were collected at two time periods (June-July and August) from all animals in the four pastures. Ash, N, cellulose and energy content were determined on all extruded samples. Fertilizer treatment had no significant effect on the nutritive content of the diet selected by the sheep. However, time of collection had significant effects on the protein and energy content of the diet selected. A significant fertilizer-collection period interaction was observed for percentage of ash.

The sequence of development of shoot system components was studied from early November 1976 through October 1977 in eastern gamagrass. Tiller production and compound shoot development began in late spring and continued until the first killing frost in mid-October. On shoots initiated in 1977, root development began in early August and peaked in September. Single shoots developed one to six mature phytomers during their first growing season. Reproductive shoot development was first noted in early May, peaked in late May, and continued into October. The proaxes of tillers, single shoots, and compound shoots perennated through the 1976-77 winter dormant period. Shoots that over-wintered as tillers had advanced to the single shoot stage by late August 1977 and had produced from 8 to 20 mature phytomers by the end of the growing season. Compound shoots initiated before 1977 developed into reproductive shoots or died by late May 1977. From May through July high percentages of the shoot system components were in the tiller and reproductive shoot stages. During this period vegetative propagation would probably not be feasible and the use of proper management practices might be more critical than during other periods.

During 1976 a study of annual production and cover (litter + rock + vegetation) on various range improvement practices was conducted in Utah, Colorado, New Mexico, and Arizona. The range improvement practices studied included gully plugs, contour furrowing, pitting, pinyon-juniper chaining, and various sagebrush control treatments. Results from studies of annual production on treated vs untreated sites indicated that: (a) about 33% of the contour furrowed sites had significant increases in annual production. Best responses were found on loam and clay loam soils, while soils of sandy loam or clay texture indicated a poor response to treatment. Soils classified as typical ustifluvents and ustollic haplargids were most favorable in terms of increased production; (b) annual production on pinyon-juniper chainings was significantly increased across a variety of soil types (growth of trees excluded). The greatest increases in production were measured on sites with loam soils classified as typic haplustolls; (c) neither of the two pitting treatments on a clay and a sandy clay loam site indicated increased annual production; (d) less than 50% of the various sagebrush treatments indicated increased annual production. There appears to be a general trend for best responses on loam soils, though significant decreases in production were also indicated on this type of soil; (e) plowing was the least successful sagebrush treatment studied. Best cover responses on the various range improvement practices were found on contour furrowing treatments on sandy clay loam and loam textured soils and on typic torriorthent or ustic torriorthent soil types. Though significant cover increases due to chaining of pinyon and juniper were noted on 57% of the treatments, on a variety of soil textures and soil types, the increases were uniformly small (tree cover included) and no clear pattern emerged with either soil texture or soil type. Only about 20% of the various sagebrush treatments showed significant increases in cover; 10% indicated decreased cover, and there was no impact on cover on the remaining 70% of the treatments. Pitting treatments in this study had no impact on cover. Age of contour furrow treatments made little difference as to whether there was a significant increase or decrease in either production or cover. Cover data from pinyon-juniper chainings indicate either that significant increases in cover (if they occur) are slightly more dramatic on more recent teatments, or that treatments approximately 11 years old represent conditions most ideal for enhanced cover. The former interpretation is probably more nearly correct. Production data suggests that pinyon-juniper sites chained since 1964 are not as favorable in terms of increased production as those chained prior to 1964. Age of sagebrush treatment had no impact on significant changes in cover; however, a general trend indicated that production increases are slightly higher for more recent sagebrush ripping and sagebrush chaining treatments than for older ones.

Tebuthiuron and glyphosate were applied at 1.1 and 2.2 kg/ha in 1976 before land preparation for the sprigging of Coastal Bermudagrass or seeding of kleingrass in the claypan region of Texas. Tebuthiuron at 1.0 kg/ha was re-applied in February 1977 either as the 80% wettable powder spray or as 3.2-mm or 1.6-mm extruded pellets, to a set of plots superimposed across the 1976 plots. Kleingrass top-growth production in 1977 was increased by the preplanting treatment with glyphosate in both rates and tebuthiuron at the low rate. Tebuthiuron at 2.2 kg/ha prevented establishment of kleingrass. Bermudagrass cover was significantly increased by a preplanting application of tebuthiuron at 1.1 kg/ha, but was not affected by preplanting application of glyphosate. Tebuthiuron at 2.2 kg/ha had no effect (beneficial or detrimental) on Bermudagrass cover. Crude protein content was higher in kleingrass from plots treated in 1976 with tebuthiuron at 1.1 kg/ha than in kleingrass from the control plots. No differences in grass stands were attributed to formulation of tebuthiuron re-applied in 1977.

Growth in Indian ricegrass commenced in the spring when soil temperatures stayed at 4 degrees C for at least 3 or 4 days. Maximum plant size was attained when (1) soils warmed up early in the spring, (2) soil temperatures were relatively low later in the spring, and (3) additional water was supplied during the spring growth period. Higher soil temperature late in the vegetative phase of growth delayed anthesis approximately 3 days for each degree Celsius above 10 degrees C. Additional moisture early in the season also delayed anthesis. Relatively reliable estimates of foliage biomass and seed biomass were made from measurements of average and/or maximum plant height, average length of longest leaf on each culm, maximum seed stalk height, clump diameter, and number of culms per plant. Measurements of biomass of needleandthread grass indicate that the generalized formulas presented here should be applicable to other cool-season bunch-grasses.

Radioactive phosphorus (P32) was used to measure root depth and lateral spread of four native plant species which had been subjected to heavy grazing for many years. Compared with root excavation measurements from an earlier study on the same area, rooting depths of all species tested were found to be quite similar by the two methods. Lateral spread differed substantially, however. Roots were found to have a greater lateral spread by the P32 estimate. The isotope method using autoradiography was found to be a sensitive method of determining depth and lateral spread of in situ plant roots in a mixed plant community.

National losses to predators of beef cattle and calves on farms and ranches with 20 or more cows and market feeder calves or yearlings were investigated. Data are from a sample survey of about 1,800 producers in five major feeder cattle regions. Losses to dogs, coyotes, and all other predators were estimated. Percentage losses are small, but financial losses reach into millions of dollars.