Simulated water spreading and nitrogen fertilization were studied on soils developed from Pierre Shales in western South Dakota. When both supplemental water and nitrogen fertilizer were applied, forage yields increased almost nine-fold. Western wheatgrass and smooth brome yields ranged from about 1,000 lb/acre on the untreated control to about 8,700 lb/acre with optimum supplemental water and 320 lb/acre nitrogen fertilizer. Forage yields increased with April and June supplemental water as compared with annual application in either April or June. Nitrogen content of harvested hay increased as nitrogen application rate increased above 80 lb/acre. Percent nitrogen decreased with increased supplemental water and ranged from about 1.2 to 2.2% in western wheatgrass and from about 1.0 to 2.3% in smooth brome. Least squares analysis, considering all nitrogen and water treatments, indicated that each lb/acre of nitrogen fertilizer applied increased the forage yield by about 19 lb/acre, and that each inch of additional water increased forage yields by about 50 lb/acre.

A field-cage study was conducted in 1973 and 1974 to determine the amount of forage (mainly grasses) destroyed by different population densities of the grasshopper Aulocara elliotti. The amount of forage consumed during the third instar and through the adult stage averaged 34.5 mg of forage per grasshopper per day. Thus, an estimated loss of 23.1 lb of forage per acre will result from a density of one Aulocara/m2 if the grasshopper lives for 75 days (45 days as a nymph and 30 days as an adult). Based on total available forage (standing dead and new growth), a 63% forage loss was recorded in 1973 at one site and losses of 26% and 29% at two sites in 1974 resulting from about 20 grasshoppers/m2. Severe grazing by grasshoppers also resulted in reduced production of forage during the subsequent (1974) season.

Plots were established in 1971 to determine the effect of herbicides on stands of green sagewort (Artemisia campestris L.). Treatments were applied in 1971, 1972, and 1973 for one study and in 1972 and 1973 for another study. Visual estimates of green sagewort control were made in 1971, 1972, 1973, and 1974. Repeat applications of 2,4-D ester at 2.24 or 3.36 kg/ha effectively controlled green sagewort whether applied in 2 or 3 consecutive years. Dicamba or picloram, each in combination with 2,4-D ester, also effectively reduced the stand of green sagewort. Green sagewort was not controlled effectively by 2,4-D ester alone at rates less than 2.24 kg/ha or 2,4,5-T at rates of 1.12 or 2.24 kg/ha. Picloram, when applied alone, was not as effective as in combination with 2,4-D ester. Retreatment is necessary when attempting to control green sagewort. Two consecutive annual application of 2,4-D ester effectively reduced the stand. After reducing the stand of green sagewort, spraying every 2nd or 3rd year as a maintenance program may be adequate to keep populations of green sagewort plants at a minimum.

Correlation analyses of records of cattle poisoned by tall larkspur (Delphinium barbeyi Huth.) on three similar and adjacent cattle allotments on the Wasatch Plateau produced low r2, indicating that losses are not related to annual fluctuations in environmental conditions or other factors shared by all three allotments. Control of the large, dense patches of tall larkspur with herbicides in one 2,000 acre subalpine pasture on the Manti Canyon Cattle Allotment dramatically reduced cattle losses. Small patches and scattered plants, which are difficult to locate and laborious to treat, apparently contribute very little to cattle losses. Examination of ruminal contents of calves found dead in the subalpine pasture in a 2-year period revealed large quantities of tall larkspur. None of the calves were orphans. All evidence suggests that the calves dying in the subalpine pastures were poisoned by tall larkspur. While mature cattle ingest lethal levels of tall larkspur in the large, dense patches, calves are apparently intoxicated by ingesting tall larkspur growing in small patches in the groves of trees scattered over the subalpine grazing units.

Water quality samples representing various flow conditions were collected from the main creeks of Streeter and Marmot experimental watersheds in southwestern Alberta. Total dissolved solids were determined gravimetrically after evaporating aliquots of filtered samples. An excellent correlation between stream discharge and yield of dissolved solids was found in the two watersheds. The regression models thus established were used to estimate the yields of total dissolved solids from the streamflow data on a daily, monthly, and annual basis. The highest yield occurred in the month of June and the lowest during the low-flow months of winter. The yield of total dissolved solids transported annually amounted to 27 metric tons per square kilometer for aspen-grassland vegetation, compared to 69 metric tons per square kilometer for spruce-fir forest.

Botanical and chemical compositions of the summer diets of esophageal-fistulated steers were determined on a deep hardland shortgrass range site of the Texas High Plains. Consumption of belvedere summercypress was highest in June, but decreased to September; whereas, consumption of blue grama, buffalograss, and sand dropseed increased during this period. Belvedere summercypress was eaten in considerable quantities until it approached dormancy. Dietary crude protein and calcium percentages were highest in June, but declined to September. Daily forage consumption averaged 10.9 kg during June and July. A forage utilization of 17.4% was obtained during the summer grazing period and the steers gained an average of .45 kg/day.

Steer gains on 'Coastal' Bermudagrass (Cynodon dactylon (L.) Pers.), utilized by continuous, weekly rotation, or daily strip grazing, or green chop, dehydrated hay, or pellet feeding, were studied for 3 years. Previous studies had included fewer methods of utilization, or had run for only a short time. Average daily gains and gains per hectare were: continuous, 594 g and 600 kg; rotation, 449 g and 469 kg; strip, 392 g and 487 kg; green chop, 369 g and 647 kg; hay, 671 g and 971 kg; and pellets, 800 g and 967 kg. Differences among grazing methods in average daily gain were largely accounted for by differences in grazing pressure. Differences among feeding methods reflected differences in forage intake and lignin content of the forage. Seasonal changes in gain and forage intake were influenced by seasonal changes in lignin content and increasing steer weights.

The effect of 25 years of weed control and grazing management on several physical properties of surface soil was measured. Bulk density of continuously grazed plots was 1.22 g/cm3 in the top 7.6 cm of soil as compared to 1.14 g/cm3 on deferred and rotationally grazed plots, and 1.02 g/cm3 on plots protected from grazing. Saturated hydraulic conductivities of 7.6 cm top soil cores from the protected plots were four times higher than from the two grazed plots. Those for warm-season grasses averaged 28.3 cm/hour, whereas mowed and smooth brome plots averaged 14.8 cm/hour. The value for the continuously grazed mowed plots was 3.0 cm/hour. The effect of long-term weed control and grazing management was reflected in the physical properties of soil which, in turn, influenced forage production by the increased water entry into soil.

The basic functional relation between foliage dry weight of big sagebrush plants and the independent variables, circumference and height of plant, was developed into a dry-weight prediction from prior knowledge and supporting information from a pertinent data set. Assuming the shape of the predictor's response surface is representative of similar plant populations elsewhere, scaler adjustment of the predictor to data from different locations, years, or subspecies would provide easy-to-use, unbiased estimators for these alternative applications. Also, the predictor can be used to improve consistency of the large-base estimates in double sampling with regression.