Root Plowing Research Articles

Plant and Small Vertebrate Composition and Diversity 36–39 Years After Root Plowing

Root plowing is a common management practice to reduce woody vegetation and increase herbaceous forage for livestock on rangelands. Our objective was to test the hypotheses that four decades after sites are root plowed they have 1) lower plant species diversity, less heterogeneity, greater percent canopy cover of exotic grasses; and 2) lower abundance and diversity of amphibians, reptiles, and small mammals, compared to sites that were not disturbed by root plowing. Pairs of 4-ha sites were selected for sampling: in each pair of sites, one was root plowed in 1965 and another was not disturbed by root plowing (untreated). We estimated canopy cover of woody and herbaceous vegetation during summer 2003 and canopy cover of herbaceous vegetation during spring 2004. We trapped small mammals and herpetofauna in pitfall traps during late spring and summer 2001–2004. Species diversity and richness of woody plants were less on root-plowed than on untreated sites; however, herbaceous plant and animal species did not differ greatly between treatments. Evenness of woody vegetation was less on root-plowed sites, in part because woody legumes were more abundant. Abundance of small mammals and herpetofauna varied with annual rainfall more than it varied with root plowing. Although structural differences existed between vegetation communities, secondary succession of vegetation reestablishing after root plowing appears to be leading to convergence in plant and small animal species composition with untreated sites.

Hispanic Farmers and Ranchers in the Soil and Water Conservation Movement in South Texas, 1940s to Present

Conservation of natural resources in South Texas is basically a modern de? velopment that parallels the evolution of the Soil Conservation Service and other federal agricultural agencies. Since the World War II era, Hispanic pro? ducers have played an important role in adopting new conservation practices to conserve and enhance the value of their lands. Initially, the region was a natural grassland devoted to ranching, but farm development in the early twentieth century led to a sharp increase in irrigated farmland along the Rio Grande. Conservation practices during the long period of extensive ranching were ineffective. As a result, by the twentieth century much of the grasslands were turned into brushland due to overgrazing, the disuse of fires to suppress weeds and useless shrubs, soil compaction, and soil and wind erosion. His? panic farmers and ranchers had to be convinced that new practices were beneftcial. The cooperation of SCS, ASCS, and other agencies facilitated the work of introducing new practices, such as disking, root plowing, seeding of new grasses, and range management practices. Farmers also benefited from new practices. Construction of Falcon Dam in 1954 was a great boost to water conservation and flood control. The last forty years have seen a rapid growth in wildlife ranches and the sale of rangelands to prosperous profes? sionals and businessmen and women. At present, three thousand Hispanic producers are dedicated to conserving their water and soil resources, adapting to these two new developments.

Hispanic Farmers and Ranchers in the Soil and Water Conservation Movement in South Texas, 1940s to Present

Abstract Conservation of natural resources in South Texas is basically a modern development that parallels the evolution of the Soil Conservation Service and other federal agricultural agencies. Since the World War II era, Hispanic producers have played an important role in adopting new conservation practices to conserve and enhance the value of their lands. Initially, the region was a natural grassland devoted to ranching, but farm development in the early twentieth century led to a sharp increase in irrigated farmland along the Rio Grande. Conservation practices during the long period of extensive ranching were ineffective. As a result, by the twentieth century much of the grasslands were turned into brushland due to overgrazing, the disuse of fires to suppress weeds and useless shrubs, soil compaction, and soil and wind erosion. Hispanic farmers and ranchers had to be convinced that new practices were beneficial. The cooperation of SCS, ASCS, and other agencies facilitated the work of introducing new practices, such as disking, root plowing, seeding of new grasses, and range management practices. Farmers also benefited from new practices. Construction of Falcón Dam in 1954 was a great boost to water conservation and flood control. The last forty years have seen a rapid growth in wildlife ranches and the sale of rangelands to prosperous professionals and businessmen and women. At present, three thousand Hispanic producers are dedicated to conserving their water and soil resources, adapting to these two new developments.

Saltcedar Recovery after Herbicide-Burn and Mechanical Clearing Practices

Mechanical clearing and herbicide-burn treatments were compared to evaluate saltcedar (Tamarix chinensis Lour.) control and recovery along the Rio Grande on the Bosque del Apache National Wildlife Refuge, Socorro, N.M. The herbicide-burn treatment included an aerial application of imazapyr (+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridinecarboxylic acid] + glyphosate [N-(phosphono-methyl)glycine] (0.6 + 0.6 kg ai ha-1 rate) followed 3 years later by a prescription broadcast fire that eliminated > 99% of the standing dead stems. Six years after initial herbicide application, saltcedar mortality was 93%. Mechanical saltcedar clearing entailed removing aerial (trunks and stems) growth by blading, stacking and burning debris, followed by removal of underground plant portions (root crowns) by plowing, raking, and burning stacked material. Saltcedar mortality 3 years after mechanical clearing averaged 70%, which was deemed unsatisfactory. Thus, root plowing, raking, and pile burning was repeated. Three years later, after the second mechanical clearing, saltcedar mortality was 97%. Costs for the herbicide-burn treatment averaged $283 ha-1, whereas mechanical control costs were $884 ha-1 for the first surface and root clearing and an additional $585 ha-1 for the second root clearing. Riparian managers should consider environmental conditions and restoration strategies prior to selecting a saltcedar control approach. Although control costs were significantly lower for the herbicide-burn treatment compared to mechanical clearing in this study, the choice of methods should always consider alternative control strategies for saltcedar. Frequently, combinations of methods result in more efficient, cost-effective results. DOI:10.2458/azu_jrm_v56i5_mcdaniel

Saltcedar recovery after herbicide-burn and mechanical clearing practices

Mechanical clearing and herbicide-burn treatments were compared to evaluate saltcedar (Tamarix chinensis Lour.) control and recovery along the Rio Grande on the Bosque del Apache National Wildlife Refuge, Socorro, N.M. The herbicide-burn treatment included an aerial application of imazapyr (+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridinecarboxylic acid] + glyphosate [N-(phosphono-methyl)glycine] (0.6 + 0.6 kg ai ha-1 rate) followed 3 years later by a prescription broadcast fire that eliminated > 99% of the standing dead stems. Six years after initial herbicide application, saltcedar mortality was 93%. Mechanical saltcedar clearing entailed removing aerial (trunks and stems) growth by blading, stacking and burning debris, followed by removal of underground plant portions (root crowns) by plowing, raking, and burning stacked material. Saltcedar mortality 3 years after mechanical clearing averaged 70%, which was deemed unsatisfactory. Thus, root plowing, raking, and pile burning was repeated. Three years later, after the second mechanical clearing, saltcedar mortality was 97%. Costs for the herbicide-burn treatment averaged 283 ha-1, whereas mechanical control costs were 884 ha-1 for the first surface and root clearing and an additional 585 ha-1 for the second root clearing. Riparian managers should consider environmental conditions and restoration strategies prior to selecting a saltcedar control approach. Although control costs were significantly lower for the herbicide-burn treatment compared to mechanical clearing in this study, the choice of methods should always consider alternative control strategies for saltcedar. Frequently, combinations of methods result in more efficient, cost-effective results.

Restoration of riparian habitat using experimental flooding

We evaluated treatments designed to remove saltcedar (Tamarix ramosissima) monocultures from riparian habitats using root plows (mechanical treatment) and aerial applications of the herbicide imazapyr (chemical treatment) within twelve 4-ha impoundments in the Middle Rio Grande Valley in central New Mexico, USA. Following these treatments, impoundments were flooded and water levels were reduced to stimulate native species re-establishment from seed. Water manipulations within salcedar-removal areas consisted of stage drawdowns of 5 cm/day and 10 cm/day. Mechanically cleared areas had fewer saltcedar resprouts (26 resprouts/ha) than chemically treated areas (2,500 resprouts/ha). Saltcedar and cottonwood (Populus deltoides subsp. wislizinii) seedling density and cottonwood survival were greater in mechanically treated areas than in chemically treated areas. This effect is attributed to soil disturbance resulting from root plowing. Cottonwood seedling density and survival did not differ between 5 cm/day and 10 cm/day stage drawdowns and decreased throughout summer as a result of excessive moisture stress. The absence of a drawdown treatment effect indicates that both drawdowns were too fast for seedling roots to keep up with declining water tables. Seedlings that survived were using moisture from the unsaturated zone.

Sustainability of agroecosystems in semi-arid grasslands: simulated management of woody vegetation in the Rio Grande Plains of southern Texas and northeastern Mexico

We describe a model that simulates use of chemical treatments, mechanical treatments (roller chopping and root plowing), and fire to manage woody vegetation in the Rio Grande Plains of southern Texas and northeastern Mexico. The model consists of two submodels representing dynamics of woody and herbaceous vegetation, respectively. Percent canopy cover of woody vegetation changes as the result of application of management schemes. Aboveground biomass of herbaceous vegetation changes as the result of differences in rates of net primary production, senescence, decomposition, and losses due to grazing and fire. The model is represented as a compartment model based on difference equations with a time step of 1 month. Model predictions of changes in canopy cover of woody vegetation, number of acres required to support a cow, and net production of herbaceous vegetation following application of each of the four treatments are similar to typical 25-year post-treatment response curves for the Rio Grande Plains. Simulation results suggest that the period of opportunity for effective use of fire to manage woody vegetation and sustain production of herbaceous vegetation is longest following root plowing, intermediate following use of chemicals, and shortest following roller chopping. In each case, the efficacy of fire in reducing canopy cover of woody vegetation diminishes rapidly as percent canopy cover increases from roughly 30–50%.

Long-Term Effects of Brush Management on Vegetation Diversity in Ephemeral Drainages

There has been recent concern regarding the effects of range management practices on biodiversity. Our objective was to determine the long-term (> 30 years) effects of chaining, and chaining followed by root plowing, on vegetation diversity in an ephemeral drainage system. Plant species richness and diversity were estimated in 2 chained (ca. 1950) areas, 2 chained (ca. 1950) and root-plowed (ca. 1960) areas, and 2 untreated areas during April 1993. Beta diversity within treatments was estimated with mean dissimilarity (l-mean similarity). Mean similarity was quantified with Jaccard's index. Spatial gradient analysis in which pairwise similarities were regressed against the distance between each pair of samples within a site was used to describe similarity within a site. Species richness and diversity were similar among treatments for both herbaceous and woody species. Similarity (Jaccard's index) among transects within a site increased with increasing degree of disturbance. Chained and root plowed sites had lower beta diversity than chained or untreated sites. Similarity in the chained and root plowed sites varied randomly, not spatially, while the control (untreated) and chained sites had negative spatial gradients, indicating spatial heterogeneity within these sites. Although root plowing did not reduce species richness and diversity as reported on upland sites in previous studies, beta diversity and habitat heterogeneity were lower on chained and root plowed sites than on chained or untreated sites.

Effects of Root Plowing on White-Tailed Deer Condition, Population Status, and Diet

Determining the effects of plant community changes on animal populations is an important area of ecological research. We compared condition, population characteristics, and diet composition of white-tailed deer (Odocoileus virginianus) from 2 root-plowed (low brush diversity) and 2 untreated (high brush diversity) sites in the eastern Rio Grande Plains of Texas to test the hypothesis that root plowing, which decreases woody species diversity-, reduced deer habitat quality. We collected 8 adult female white-tailed deer from each site every 3 months for 6 sampling periods. We assessed condition from several physiological, reproductive, and digestive indices and determined food habits by microhistological analysis of rumen samples. We estimated population size from helicopter surveys

Long-Term Effects of Root Plowing on Vegetation in the Eastern South Texas Plains

The long-term effects of root plowing in plant communities in south Texas are not clearly understood. Our objective was to compare plant species composition and diversity on root-plowed rangelands and untreated rangelands. Two rangeland sites that were root plowed during 1973-74 and 2 sites of native, untreated brush were selected on the Santa Gertrudis Division of the King Ranch, Kleberg and Jim Wells counties, Texas. Woody plant canopy cover was estimated with the line intercept method, and density was estimated with 20-X 1-m plots during 1990. Herbaceous canopy cover was estimated with 20 X 50-cm quadrats. Percent grass, lifter, and bare ground coverage were similar on root-plowed and untreated rangelands. Woody plant species and diversity averaged 19 +/- 2 species/ treatment (average +/- SE) and 2.56 +/- 0.15 on untreated areas compared to 7 +/- 1 species/treatment and 1.18 +/- 0.01 on root-plowed areas. Forb canopy coverage on root-plowed sites was about twice that of untreated sites. Huisache (Acacia smallii Ilsey) canopy cover and density were both more than 7-fold greater on root-plowed sites than on untreated sites. Browse species preferred by white-tailed deer (Odocoileus virginianus Raf.), such as colima [Zanthoxylum fagara (L.) Sarg.] and guajillo (Acacia berlandieri Benth.), were absent on root-plowed sites.

Effects of Cattle Trampling and Mechanical Seedbed Preparation on Grass Seedling Emergence

Cattle trampling has been recommended to bury seeds and encourage seedling establishment but has not been compared with traditional seedbed preparation techniques. We compared seedling emergence of broadcast-seeded 'Vaughn' sideoats grams [Bouteloua curtipendula (Michx.) Torr], 'A-130' blue panic (Panicum antidotale Retz.), 'A-68' Lehmann lovegrass (Eragrostis lehmanniana Nees), and 'Cochise' atherstone lovegrass (Eragrostis lehmanniana Nees X E. tricophera Coss and Dur.) on lightly and heavily trampled seedbeds with that on undisturbed, land imprinted, and root-plowed or ripped seedbeds. We seeded and applied the treatments prior to summer rains on a sandy loam soil in southern Arizona for 3 years. In a wet year (1987) when surface soil water was estimated to be available for at least 24 consecutive days, heavy trampling and land imprinting increased emergence of blue panic and land imprinting increased emergence of Cochise lovegrass. In that year, lovegrass emergence was high even on undisturbed plots. In a moderately wet year (1988), surface soil water was available for periods of 6-9 days during seedling emergence and greater disturbance, either by heavy trampling, land imprinting and/or root plowing or ripping produced higher emergence than light trampling and nondisturbance. In a dry year (1989), surface soil water was available for periods of 2-3 days and seedling emergence was low and generally similar for all treatments. Sideoats grama emergence was low all 3 years, but was highest in 1988 when initial thunderstorms were followed closely by subsequent storms. Seedbed disturbance by cattle and mechanical methods may enhance revegetation in the Southwest in years of moderate precipitation but may be unnecessary in wet years or futile in dry years, depending on species and soils.

Soil response to cattle trampling and mechanical seedbed preparation

Abstract Cattle trampling and mechanical cultivation have been recommended to prepare seedbeds in association with rangeland revegetation. The effects of one‐time light and heavy cattle trampling, land imprinting, and root plowing or ripping on physical and hydrologic characteristics of a sandy loam soil were measured in southern Arizona. Soil disturbance by these treatments initially increased soil penetrability and slightly increased bulk density. Land imprinting increased the depth of wetting of an initial rainstorm but not sorptivity. Plowing or ripping increased surface roughness, penetrability, depth of wetting, and sorptivity. Heavy trampling and land imprinting initially increased the volume of water that was held at field capacity by the surface soil. This effect did not persist after summer rainfall. None of the treatments strongly positively or negatively affected soil physical properties. One‐time heavy cattle trampling slightly increased depth of wetting but not sorptivity compared to undistu...

MODELING THE EFFECT OF BRUSH CONTROL ON RANGELAND WATER YIELD1

ABSTRACT: With the increase in water demand in Texas, attention has turned to improving water yield by brush control on rangeland watersheds. Several hydrologic models have been developed for either farmland or rangeland. However, none of the models were specifically developed to assess the impact of brush control on rangeland water yield. Yet, modeling the impact of brush control on water yield needs to be considered if alternative techniques are to be compared. Two models, Ekalaka Rangeland Hydrology and Yield Model (ERHYM‐II) and Simulator for Water Resources on Rural Basins (SWRRB) were selected. The Soil Conservation Service curve number (SCS‐CN) method is used in both models to predict surface runoff from each rainfall event. The major differences between the ERHYM‐II and SWRRB models are the evapotranspiration, soil water routing, and plant growth components. The models were evaluated on brush‐dominated and chemically and mechanically brush‐controlled range watersheds in Texas. Results indicated that both models were capable of simulating soil water and water yield from brush dominated and chemically brush‐controlled range watersheds. The models were not able to predict water yield from the mechanically brush‐controlled (root plowed) watershed with acceptable accuracy. The depressions that were caused by root plowing stored surface runoff and reduced water yield from the watershed. Information about the size of depressions was not available for further model evaluation.

Germination of Texas Persimmon Seed

Germination of Texas Persimmon Seed

Density and Production of Seeded Range Grasses in Southeastern Arizona (1970-1982)

Density and Production of Seeded Range Grasses in Southeastern Arizona (1970-1982)

Infiltration and Sediment Production on a Deep Hardland Range Site in North Central Texas

Greatest infiltration rate and lowest sediment production most closely associated with variations in infiltration capacity and occurred in the honey mesquite canopy zone. Infiltration on sediment production. shortgrass interspace areas was about one-half of the canopy zone rate. Terminal infiltration rates within the canopy zone and Study Area shortgrass interspace areas were affected little by brush control treatments. Infiltration rate improvement due to treatment occurred primarily in the midgrass interspace areas. Water-stable aggregates and the interaction of soil aggregate stability with the amount of bare ground were the dominant factors controlling infiltration. Sediment production on the shortgrass interspace was double that of the canopy zone or midgrass interspace areas. Low rate of sediment production on the midgrass interspace areas occurred on areas aerially sprayed or root plowed 3 years earlier. Sediment production was controlled primarily by an interaction of soil organic matter and amount of above-ground biomass or grass cover. Past land management practices have resulted in large increases of honey mesquite (PTosopis glandulosa Torr. var. glandulosa) which now occurs on 56 million acres of Texas rangeland, including 34 million acres which are moderately to heavily infested (Fisher et al. 1973). Most of the heavily and moderately infested rangelands currently produce much less forage than their potential and require control of the honey mesquite to improve forage production. Herbicides and root plowing are widely accepted tools for improving honey mesquite dominated rangelands. However, little information exists for Texas rangelands relative to the impact of honey mesquite control on infiltration rates and sediment production. In other areas, brush control practices have apparently increased infiltration rates and decreased erosion (Rosa and Tigerman 1951, Rich 1961, Rowe and Reimann 1961, Dragoun 1969, Blackbum and Skau 1974). Yet, in some cases, these practices have failed to improve watershed condition (Rowe and Reimann 1961, Blackburn and Skau 1974, Gifford and Busby 1974). Blackburn (1975) reported sagebrush (Artemesia spp.) canopy zones to have exceedinalv high infiltration rates. sometimes 3 to 4 Field research was conducted on the W.T. Waggoner Estate southwest of Vernon, Texas. Theestate is part of the Rolling Plains land resource area which comprises approximately 6.32 million ha of rolling to rough topography in northwest Texas (Gould 1975). Normal annual precipitation for Vernon, Texas, is about 65 cm, with May, June, and October being the months of highest precipitation and January being the driest month (USDC 1976). The average frost-free period is 232 days (Koos et al. 1962). Climax vegetation of the Rolling Plains include tall and midgrasses, but continuous heavy utilization by cattle has reduced the vegetation to primarily short and midgrasses with varying densities of woody plants. Honey mesquite, with a mean height of 1.6 m, a mean density of 437 plants/ ha and a 21% canopy cover, dominated the study area prior to treatment. Lotebush (Ziziphus obrusifolia (T.G.) Gray), tasajillo (Opuntia leprocaulis D.C. var leptocaulis), and grassland prickly pear (Opuntia rnacrorhiza Engelm.) were common on the study area. Herbaceous vegetation was typified by Texas wintergrass (Sripa feucotricha Trin. and Rupr.), Arizona cottontop (Digitaria calryornica (Benth.) Henr.), little barley(Hordeum pusillum (Nutt.)), rescuegrass (Bromus unioloides (Willd.) H.B.K.), buffalograss (Buchloe dacfyloides (Nutt.) Engelm.), sand dropseed (Sporobolus cryptandrus (Torr.) Gray), and purple threeawn (Aristida purpurea (Nutt.)).

Archaeological Testing of Sites 41MK28 and 41MK29 McCulloch County, Texas

Two sites in McCulloch County, Texas, Sites 41MK28 and 41MK29, were tested in August, 1981, and were found to have very shallow of surface deposits. Site 41MK28 proved to be a badly eroded surface site. That portion of Site 41MK29 which lay in the proposed right-of-way was found to be already destroyed by previous root plowing and fire lane construction activities. Further excavation is not recommended at either site because of the disturbed nature of the sites and the lack of depth to the deposits.