M. Karl Wood

Vegetation and soil responses to cattle grazing systems in the Texas rolling plains.

The influence of erttle gr8zing on selected veget8tion 8nd soil p8rrmeters were eV8lU8ted on 8 clay Bat range site with shrub zon81, midgrass, and shortgr8ss communities in the Rolling Plrins ne8r Throckmorton, Texur. Measurements were mide on one prsture of each trertment during 1977 following 4 to 20 yerrs of gr8zbtg tre8tments. He8vy, continuous c8ttie yaxing hrd more 8re8 occupied by the shortgr8ss community th8n midgrass community. He8vily gnzed pastures were genenlly dominrted by the shortgrass community, with midgmsses, depending on the degree of utilization, restricted to the shrub zonal community. Conversely, cattle exclosures h8d no shortgrass community, 8nd deferredrotrtion and moderrtely stocked continuously grazed systems hrd much midgrass community with the shortgross community occup ylng only 30% of the area, thus increasing mnge productivity. Veget8tion 8nd soil parameters within the high intensity, low frequency md heavily stocked, continuously gr8xed prstures tended to be similar for the midgrass 8nd shortgmss communities, but the shrub zonal community was generally different. Vegetation md soil parameters in the midgrass community of the moderrrtely stocked, continuously grazed treatment were gener8lly simil8r to shrub zonnl 8nd different from shortgrass communities. Vegetation and soil Vlriables in the exclosures and deferred-rotation treatments were generally similrr among the midgrass md shrub zonal communities; however, they differed from the shortgr8ss communities.

Influence of Crusting Soil Surfaces on Emergence and Establishment of Crested Wheatgrass, Squirreltail, Thurber Needlegrass, and Fourwing Saltbush

Crusting soil surfaces with vesicular pores occur in arid and semiarid regions of the world where herbaceous vegetation is sparse. Morphological properties of crusting surfaces can impair seedling emergence and plant establishment. This study evaluated site preparation and seeding methods and species useful for encouraging successful stand establishment in such soils. Plowing to prepare a seedbed reduced seedling emergence on some soils but increased plant establishment on all soils. More seedlings emerged and established on non-crusting coppice soil beneath shrubs than on crusting interspace soil between shrubs. Crested wheatgrass was the most successful species followed closely by squirreltail and distantly by Thurber needlegrass and fourwing saltbush. Fourwing saltbush seedlings became established and grew well in some treatments. Seedling emergence and establishment were highest with the deep-furrow seeding technique on the non-crusting coppice soil. The standard-drill technique gave the best stand on the site with the largest surface cover of bare, crusting interspace soil. Soils with crusting surfaces occur in many arid and semiarid regions of the world. Various features of these soils in the western United States were described by Hugie and Passey (1964) and Schlatterer (1968). In the Great Basin these soils commonly are associated with northern-desert shrub and salt-desert shrub plant communities that have sparse herbaceous vegetation. In northern Nevada, such soils are found in the Humboldt Loess Belt, an &million-ha area of shallow, windblown silt and very fine sand deposition. These soils are on gently sloping fan piedmonts and nearly level alluvial flats. They include both typic and xerollic Durargids, Haplargids, Nadurargids, and Natrargids and have moderately fine and fine textured B2t horizons. These soils generally are crusted between shrubs (interspace soil) and are noncrusted beneath the shrubs (coppice soil) (Stuart et al. 1971, Blackburn 1975). The microtopographic positions, surface physiognomy, and morphological characteristics of the A horizon were presented by Eckert et al. in 1978. These surficial features are not mapped or measured even in detailed soil surveys, but must be determined on a site by site basis. The crusting interspace surfaces commonly are sandy loam, loam, or silt texture high in very fine sand or silt, with low organic matter content, are massive, and have vesicular pores. These factors contribute to the unfavorable behavThe authors are presently assistant professor of watershed management, Department of Animal and Range Sciences and Range Improvement Task Force, New Mexico State University, Las Cruces, 88003; range scientist, U.S. Dep. Agr., Agr. Res. Serv. Renewable Resources Center, University of Nevada, 920 Valley Road, Reno, 89512; professor of watershed management, Range Science Department, Texas A&M University, College Station, 77843; and professor of Soil Science, Plant, Soil. and Water Science Division, University of Nevada, Reno, 89512. This study was a cooperative investigation among U.S. Dep. Agr., Agr. Res. Serv., Bureau of Land Management, and Agr. Exp. Sta., Univ. of Nevada, Reno. Journal Series No. 483. Plant nomenclature follows Plummer et al. (1977). Manuscript received August 20, I98 I. 282 ior of this surface: unstable and slakes when saturated, dries to a crust that can reduce seedling emergence (Wood et al. 1978), and has a low water infiltration rate and high sediment production (Blackburn 1975). Wood et al. (1978) stated that rangelands with these kinds of soils have higher potential productivity than their present fair to poor condition suggests. These authors postulated that theareas of crusting interspace soil increase with overgrazing, loss of herbaceous cover, and lowered range condition at the expense of noncrusting coppice surface soil. They also stated that revegetation of these problem soils through grazing management alone would be difficult, if not impossible, in a reasonable time and that artificial seeding methods are required to establish forage species. Therefore, we evaluated seedling emergence and plant establishment of various species seeded by different techniques on soils with crusting and non-crusting surfaces.

Livestock grazing impacts on infiltration rates in a temperate range of Pakistan

This study was conducted in a temperate range of northern Pakistan in 1987 and 1988. The main purpose of the experiment was to determine a suitable residual phytomass level for the moist temperate ranges of Pakistan. Data were collected for 2 consecutive growing seasons. A completely randomized design, with 4 treatments and 2 replications, was used. The treatments were 4 different residual phytomass levels. A rainfall simulator applied rainfall to 48 flexible circular plots (1m2). Analysis of variance and the LSD multiple mean comparisons determined treatment differences, and stepwise multiple regression identified the important vegetation and soil variables affecting infiltration. The control (no grazing) resulted in the highest infiltration while the treatment having the lowest residual phytomass had the lowest infiltration. Among the independent variables, standing phytomass was the most important variable affecting infiltration. Foliar and basal cover were also highly correlated to infiltration.

Development of a rainwater harvesting system for increasing soil moisture in arid rangelands of Pakistan

Soil moisture can be significantly increased with microcatchments that have 4 to 5 m long water catchment aprons and 7 to 15% slope gradients. The increase was by 59% (from 10·9 to 17·3% vol/vol) from the surface to 15 cm depth, by 63% (from 11·5 to 18·8% vol/vol) from 15 to 30 cm depth, and by 80% (from 11·3 to 20·3% vol/vol) from 30 to 45 cm depth. Increases in soil moisture were found in both the late summer and the late winter season when the highest precipitation is received. There are some year-to-year differences depending on how much precipitation is received each year. Rill erosion on the aprons increased with apron length and gradient. Erosion volumes were quite low (14·9 1 to 26·3 1) considering the amount of area of an apron (120 and 150 m2).

Rainwater harvesting for increasing livestock forage on arid rangelands of Pakistan.

This study determined forage production and cover of several plant species resulting from the use of water harvesting catchments with catchment: cultivated area ratios of 1:1 and 1.25:1 and contributing aprons with 7, 10, and 15% slope gradients. Plots with 1.25:1 ratios produced more forage and had more cover than plots with 1:1 and 0:1 ratios. Plots with 7, 10, and 15% slope gradients had similar forage production and cover. Tuft planted plots produced more forage and cover than seeded plots. Ghorka (Elionurus hirsutus (Vahl) Munro), blue panicum (Panicum antidotale Retz.), and buffer (Cenchrus ciliaris L.) grasses produced similar forage and cover, which was higher than khev grass (Sporobolus helvolus (Trin.) Th. Dur. & Schinz) production and cover.

New Mexico Blue Grama Rangeland Response to Dairy Manure Application

Abstract New Mexico supports over 290 000 dairy cattle. These cattle produce large quantities of manure. It has been suggested excess dairy manure could be applied to rangelands as an organic fertilizer to increase soil fertility and herbaceous production. Manure was applied June 2000 to a rangeland in New Mexico dominated by blue grama (Bouteloua gracilis (Willd. ex Kunth) Lag. ex Griffiths) according to phosphorus (P) content: a recommended (light) rate (54 kg P·ha−1) to enhance blue grama growth and a gross overapplication (heavy) rate (493 kg P·ha−1) to determine their effects on vegetation. The actual application rate of manure on a dry weight basis was 0, 11 739, and 107 174 kg·ha−1. Four replications of control, light, and heavy rates were established. Herbaceous standing crop (kg·ha−1) was similar 1 growing season after manure application, and greater 2 and 3 growing seasons after application on the light treatment compared with the control. Initially the heavy treatment suppressed herbaceous standing crop; thereafter, standing crop responded in a linear fashion to rainfall. Three growing seasons after manure application, basal cover was similar between light and control treatments, whereas the heavy treatment continued to be characterized principally by manure/litter cover. Heavy disposal-oriented treatments are not suitable for blue grama rangelands because of persistent declines in herbaceous cover and changes in soil salinity. A light manure application rate that is based on P content can increase forb and in particular grass standing crop on arid blue grama rangelands. Successful rangeland manure applications will depend on proper management to insure objectives are met while minimizing any hazards to the environment.

Infiltration rates and erosion associated with reclaimed coal mine spoils in west central New Mexico

Abstract Large quantities of coal are extracted in New Mexico by surface mining that results in large areas of surface disturbance. Some goals of reclaiming these disturbances are to control erosion and consequent sediment yields by recontouring and revegetation. This study investigates the rates of infiltration and sediment removal on successfully reclaimed coal mine areas, and their relationship with analogous undisturbed rangeland. Reclaimed areas that had been revegetated for one, three and five years, and a nearby natural rangeland, were subjected to simulated rainfall. Ponding time and runoff time were similar between the non-disturbed lands and the areas reclaimed one and five years before for both dry and wet soil moisture scenarios. The area revegetated three years before required substantially longer time to pond and yield runoff than the rangeland. The reclaimed areas with three and five growing seasons displayed greater infiltration rates than the rangeland area on dry soils and wet soils. Infiltration rates for the reclaimed area with one growing season were similar to the natural rangeland area for both soil moisture conditions. Sediment production and concentrations on the newly reclaimed areas were equal to, or greater than, that for the rangeland on dry and wet soils, respectively. The reclaimed area with the most established vegetation yielded the least sediment of all the reclaimed sites, and significantly less than the rangeland site, regardless of soil moisture situations. Various vegetation, rock, soil, and surface roughness variables were found to influence ponding and runoff times, infiltration rates, sediment production, and sediment concentration. These variables include, in decreasing importance: foliar grass cover, grass production, bulk density, foliar shrub cover, shrub production, horizontal roughness, litter cover, vertical roughness, rock cover and organic matter content.

The relationship of soil surface roughness with hydrologic variables on natural and reclaimed range land in New Mexico

Abstract Soil surface roughness values have been used to predict runoff and infiltration rates from crop lands, forest lands, and range lands. The strength of association between roughness and runoff and infiltration has been weak as shown with correlation analysis. The purpose of this study was to determine relationships of roughness on the contour to roughness perpendicular to the contour as related to infiltration rates and sediment production on range lands. Roughness up and down slopes (vertical) gave a higher correlation than roughness along the contour (horizontal). Adding or subtracting the vertical and horizontal roughness did not increase correlation values. Highest correlation values resulted from entering vertical and horizontal roughness values into a multiple regression equation.

OCCURRENCE OF SPROUTS AND SEEDLINGS OF PINYON PINES, ALLIGATOR JUNIPERS, AND GRAY OAKS FOLLOWING HARVEST OF FUELWOOD AND PRESCRIBED BURNING

Abstract Objectives were to determine number and height of sprouts and seedlings following clearcutting of a mesa dominated by pinyon pines (Pinus edulis) and alligator junipers (Juniperus deppeana) in southwestern New Mexico and to determine effects of prescribed burning for control of sprouts and seedlings. No stump of pinyon pine sprouted. Nearly 50% of stumps of alligator junipers sprouted with most occurring in plots with slash removed; the fewest and tallest sprouts occurred in plots with slash uniformly scattered following clearcutting. Nearly 25% of stumps of gray oaks (Quercus grisea) sprouted. Burning in the same year as clearcutting did not affect sprouting of gray oaks as much as other treatments. Not burning clearcuts and leaving slash scattered resulted in the fewest sprouts, and shortest sprouts of gray oaks occurred in plots with slash removed. Seedlings of pinyon pines, alligator junipers, and gray oaks were most prevalent in uncut control plots. Some seedlings of alligator junipers were in plots with slash scattered and removed, and few seedlings were in plots that were burned. Most seedlings of gray oaks were in uncut control plots and plots where slash was removed. Seedlings of pinyon pines grew tallest in plots with slash removed, seedlings of alligator junipers grew tallest in plots where slash was scattered, and seedlings of gray oaks grew tallest in all plots except the uncut control.