Pasture Development Research Articles

The northern Australian beef industry, a snapshot. 5. Land and pasture development practices

The land and pasture development practices of 375 northern Australian beef properties in 8 regions were surveyed during 1996–97. These properties represented a broad cross-section of the beef industry in terms of geographical location, enterprise and herd size, and ownership structures. Both tree clearing and killing were more common in Queensland than in the Northern Territory or northern Western Australia. In all regions where trees were poisoned, native pasture was more widely used than sowing introduced grass and/or legume species. In contrast, tree clearing was most often accompanied by sowing pastures (either an introduced grass only or introduced grass and legume species together), rather than using native pastures. Central coastal Queensland had the highest use of poisoning trees for pasture development. Tree clearing and using native pasture was most important in central Queensland regions and the Maranoa South West. Sowing introduced pasture species under live trees was more commonly practiced in northern Queensland, the Northern Territory and northern Western Australia than in other regions. A considerable number of introduced grass and legume species were sown by producers. Most of the sown species were grasses. Many of the sown grass and legume species were spreading naturally. Buffel grass was spreading in all areas with < 1000 mm average annual rainfall, but most sown species were spreading only in wetter regions. Stylosanthes spp. were the most commonly spreading legume species in regions with > 500 mm average annual rainfall. The results are discussed in relation to contemporary natural resource management issues and how this may affect land and pasture development activities in the future.

Pasture production in cleared and uncleared grazing systems of central Queensland, Australia

Clearing land of trees and introducing exotic pastures to enhance pasture and cattle production and hence enterprise financial performance are widely practised in Queensland. The results from many previous studies on tree clearing have emphasised the gains in pasture production, but over periods of less than 10–15 years after clearing. The present study questioned the sustainability of pasture production in cleared systems over a longer time-frame (>10 years of clearing). For this, three different age groups of clearing i.e. 5 year, 11–13 year and 33 year were selected in each of 3 major types of tree communities i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla in central Queensland. Paired comparisons of cleared and uncleared (intact) pasture systems were selected for each age group of clearing. The results suggest that the initial gains in pasture production upon clearing were compatible with published studies. However, for longer periods of time since clearing, the gains in pasture production were not sustained and were accompanied by risks of land degradation and loss of pasture plant diversity. For E. populnea and A. harpophylla, the maximum benefits from clearing were achieved at 13–15 years whereas for E. melanophloia, any benefits existed only over a short period of 5–6 years. The study emphasises that each tree community exhibits a specific response with regard to the duration of increased pasture production following clearing. To estimate the total benefits from tree clearing in pasture development, it is important to consider both monetary benefits and non-monetary losses from clearing for different types of tree communities.

Total soil organic matter and its labile pools following mulga (Acacia aneura) clearing for pasture development and cropping 1. Total and labile carbon

Mulga (Acacia aneura) dominated vegetation originally occupied 11.2 Mha in Queensland, of which 12% has been cleared, mostly for pasture production, but some areas are also used for cereal cropping. Since mulga communities generally occupy fragile soils, mostly Kandosols and Tenosols, in semi-arid environments, clearing of mulga, which continues at a rate of at least 35 000 ha/year in Queensland, has considerable impact on soil organic carbon (C), and may also have implications for the greenhouse gas emissions associated with land use change in Australia. We report here the changes in soil C and labile C pools following mulga clearing to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for 20 years in a study using paired sites. Soil organic C in the top 0.05 m of soil declined by 31% and 35% under buffel pasture and cropping, respectively. Land use change from mulga to buffel and cropping led to declines in soil organic C of 2.4 and 4.7 t/ha, respectively, from the top 0.3 m of soil. Using changes in the δ13C values of soil organic C as an approximate representation of C derived from C3 and C4 vegetation from mulga and buffel, respectively, up to 31% of soil C was C4-derived after 20 years of buffel pasture. The turnover rates of mulga-derived soil C ranged from 0.035/year in the 0–0.05 m depth to 0.008/year in the 0.6–1 m depths, with respective turnover times of 29 and 133 years. Soil organic matter quality, as measured by the proportion/amount of labile fraction C (light fraction, < 1.6 t/m3) declined by 55% throughout the soil profile (0–1 m depth) under both pasture and cropping. There is immediate concern for the long-term sustainable use of land where mulga has been cleared for pasture and/or cropping with a continuing decline in soil organic matter quality and, hence, soil fertility and biomass productivity. In addition, the removal of mulga forest over a 20-year period in Queensland for pasture and cropping may have contributed to the atmosphere at least 12 Mt CO2-equivalents.

Total soil organic matter and its labile pools following mulga (Acacia aneura) clearing for pasture development and cropping. 2. Total and labile nitrogen

Mulga (Acacia aneura) woodlands and open forests occupy about 150 Mha in Australia, and originally occupied 11.2 Mha in Queensland. Substantial areas (1.3 Mha) of the mulga vegetation have been cleared in Queensland, mostly for pasture production, but some areas are also used for cereal cropping. Twenty years after mulga clearing we found a significant loss of total soil organic C (28–35% from the 0–0.05 m depth) and light fraction C (>50% from the 0–1 m depth) from soil under pasture and cropping at a site in southern Queensland. We report here the changes in soil N and labile N pools in a paired-site study following conversion of mulga to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for more than 20 years. Conversion from mulga forest to pasture and cultivation resulted in greater losses of soil N than organic C in the top 0.1 m depths. As a result, C/N ratios in soil under both pasture and cropping were higher than soil under mulga, indicating a decline in soil organic matter quality after mulga clearing. Although land-use change had no significant effect on 15N natural abundance (δ15N) values of total soil N down to a depth of 1 m, δ15N values of wheat tops and roots indicated that the primary source of N under cropping was soil organic N, while that of buffel pasture was a mixed source of soil N and decomposed litter and root N. Light fraction N (<1.6 Mg/m3) declined by 60–70% throughout the 1 m soil profile under pasture and cropping, but it was 15N-enriched in these 2 land-use systems. The δ15N values of mulga phyllodes, twigs, and fine roots, indicated an input of atmospheric fixed N2 that was estimated to be about 25 kg N/ha.year. However, the source and magnitude of this N resource needs to be confirmed. Soil N losses were estimated to be 12 kg N/ha.year under pasture and 17 kg N/ha.year under cropping over a 20-year period. These findings raise the issue of the long-term sustainable use of cleared mulga areas for pasture and/or cropping. The labile C and N pools and N mineralised also declined, which would have an immediate adverse effect on soil fertility and plant productivity of cleared Mulga Lands, as well as reducing their potential as a soil sink for greenhouse gases.

Manejo da irrigação em pastagem irrigada por pivô-central

A aplicação de lâminas de irrigação em pastagem irrigada sob pivô-central é, de maneira geral, realizada sem um critério técnico pertinente ao sistema, pois se deve considerar que para um mesmo período a pastagem se encontra em diferentes estádios de desenvolvimento em cada parcela, apresentando taxas de evapotranspiração diferenciadas dentro da área irrigada; todavia, usualmente se aplica uma única lâmina para toda a área. Neste trabalho foi desenvolvido um modelo para aplicação de lâminas de irrigação distinta para cada parcela do pivô o qual, de modo geral, considera: i) a capacidade do pivô-central de aplicar lâminas distintas na área; ii) o nível de desenvolvimento da cultura em cada parcela; iii) o período de retorno do gado a determinada parcela (ciclo de pastejo); e iv) o potencial de desenvolvimento da pastagem de certa região. Para modelar o coeficiente de cultura (Kc) foram utilizadas duas metodologias, a primeira com taxa de variação do Kc constante com o número de dias em que a parcela está em descanso (k), e a segunda, com taxa de variação do Kc na forma senoidal com k. O modelo foi aplicado para pastagens hipotéticas nas regiões de Piracicaba e Pereira Barreto, para avaliação e, como resultado, observou-se que o modelo se mostrou sensível ao nível de desenvolvimento de cada parcela e às condições de variação do clima de cada região.

Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions

Abstract. A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted monthly hydrographs. The observed and predicted monthly runoff for all catchments matched well with coefficients of determination (R2) ranging from 0.68 to 0.87. Predictions were relatively poor for: (i) the Ernies catchment (lowest rainfall, forested), and (ii) months with very high flows. Overall, the predicted mean annual streamflow was within ±8% of the observed values. Keywords: monthly streamflow, land use change, conceptual model, data-based approach, groundwater

Landscape use by cattle affected by pasture developments and season

Allowing cattle (Bos taurus L.) unrestricted access to streams can contribute to degradation of riparian and aquatic habitats. The objectives of this study were (1) to quantify the amount of time cattle spend using streams and associated riparian habitats when off-stream water and shade sources are offered and (2) to relate these patterns of habitat use to diurnal and seasonal changes in environmental conditions characteristic of the lower southeast. Diurnal (dawn-to-dusk) patterns of cattle location and behaviors were monitored between March 2000 and October 2001 in north-central Alabama at farms with pastures in which wooded streams were present. No significant decrease was detected in the length of diurnal periods cattle spent in riparian habitats after water and shade developments were in place. Grazing (7.8 hours) dominated daytime behaviors of cattle during the cool season when preference was for grassland habitat (7.6 hours). During the warm season, time spent lying increased to 4.7 hours versus 2.7 hours during the cool season; cattle consistently sought either riparian or other wooded habitat at midday and afternoon in comparison to morning and evening periods. Overall, grazing behaviors occurred predominantly (80%) in grassland habitat and lying behaviors occurred mainly (60%) in wooded habitat. Results suggested that comfort (relief from heat stress) appeared to be a major criterion in habitat use decisions by cattle during the warm season for the relatively small spatial scales (3.3 and 6.9 ha) studied. Therefore, dependence only on water and shade developments for alterations in livestock distribution may not be the most effective strategy for reduced degradation of many riparian habitats found in this region.

Landscape Use by Cattle Affected by Pasture Developments and Season

Landscape Use by Cattle Affected by Pasture Developments and Season

EARLY ADOPTION OF THE TROPICAL FORAGE LEGUME ARACHIS PINTOI IN HUETAR NORTE, COSTA RICA

The legume Arachis pintoi has a number of characteristics which enable it to make a valuable contribution to the development of sustainable and productive pastures in the tropics. It was introduced to Costa Rica for this reason, in 1987. The objective of this study was to analyse the adoption of A. pintoi as a forage legume in Huetar Norte, a region in the north of Costa Rica. The adoption process was analysed to identify the contributory factors and to make recommendations for measures which could be taken to promote the process. To collect the data, 115 randomly selected livestock holders and an additional 34 farmers known to have planted A. pintoi were interviewed. Farmers see improved pastures to be the most important technology to enhance forage and cattle production. It was confirmed that A. pintoi is a potential improved pasture alternative. Although A. pintoi was well known., the adoption rate was low. Lack of availability of seed, technical assistance and information about the use and management of A. pintoi hinder adoption. Difficulties in establishment and maintenance were also recorded.

Landscape use by cattle affected by pasture developments and season

Allowing cattle (Bos taurus L.) unrestricted access to streams can contribute to degradation of riparian and aquatic habitats. The objectives of this study were (1) to quantify the amount of time cattle spend using streams and associated riparian habitats when off-stream water and shade sources are offered and (2) to relate these patterns of habitat use to diurnal and seasonal changes in environmental conditions characteristic of the lower southeast. Diurnal (dawn-to-dusk) patterns of cattle location and behaviors were monitored between March 2000 and October 2001 in north-central Alabama at farms with pastures in which wooded streams were present. No significant decrease was detected in the length of diurnal periods cattle spent in riparian habitats after water and shade developments were in place. Grazing (7.8 hours) dominated daytime behaviors of cattle during the cool season when preference was for grassland habitat (7.6 hours). During the warm season, time spent lying increased to 4.7 hours versus 2.7 hours during the cool season; cattle consistently sought either riparian or other wooded habitat at midday and afternoon in comparison to morning and evening periods. Overall, grazing behaviors occurred predominantly (80%) in grassland habitat and lying behaviors occurred mainly (60%) in wooded habitat. Results suggested that comfort (relief from heat stress) appeared to be a major criterion in habitat use decisions by cattle during the warm season for the relatively small spatial scales (3.3 and 6.9 ha) studied. Therefore, dependence only on water and shade developments for alterations in livestock distribution may not be the most effective strategy for reduced degradation of many riparian habitats found in this region.

Landscape use by cattle affected by pasture developments and season

Allowing cattle (Bos taurus L.) unrestricted access to streams can contribute to degradation of riparian and aquatic habitats. The objectives of this study were (1) to quantify the amount of time cattle spend using streams and associated riparian habitats when off-stream water and shade sources are offered and (2) to relate these patterns of habitat use to diurnal and seasonal changes in environmental conditions characteristic of the lower southeast. Diurnal (dawn-to-dusk) patterns of cattle location and behaviors were monitored between March 2000 and October 2001 in north-central Alabama at farms with pastures in which wooded streams were present. No significant decrease was detected in the length of diurnal periods cattle spent in riparian habitats after water and shade developments were in place. Grazing (7.8 hours) dominated daytime behaviors of cattle during the cool season when preference was for grassland habitat (7.6 hours). During the warm season, time spent lying increased to 4.7 hours versus 2.7 hours during the cool season; cattle consistently sought either riparian or other wooded habitat at midday and afternoon in comparison to morning and evening periods. Overall, grazing behaviors occurred predominantly (80%) in grassland habitat and lying behaviors occurred mainly (60%) in wooded habitat. Results suggested that comfort (relief from heat stress) appeared to be a major criterion in habitat use decisions by cattle during the warm season for the relatively small spatial scales (3.3 and 6.9 ha) studied. Therefore, dependence only on water and shade developments for alterations in livestock distribution may not be the most effective strategy for reduced degradation of many riparian habitats found in this region.

Managing woodlands for income maximisation in western Queensland, Australia: clearing for grazing versus timber production

Queensland, Australia, has a proud pastoral history; however, the private and social benefits of continued woodland clearing for pasture development are unlikely to be as pronounced as they had been in the past. The environmental benefits of tree retention in arid regions of the State are now better appreciated and market opportunities have arisen for the unique timbers of western Queensland. A financial model is developed to facilitate a comparison of the private profitability of small-scale timber production from remnant Acacia woodlands against clearing for pasture development in the Mulga Lands and Desert Uplands bioregions of western Queensland. Four small-scale timber production scenarios, which differ in target markets and the extent of processing (value-adding), are explored within the model. Each scenario is examined for the cases where property rights to the timber are vested with the timber processor, and where royalties are payable. For both cases of resource ownership, at least one scenario generates positive returns from timber production, and exceeds the net farm income per hectare for an average grazing property in the study regions over the period 1989–1990 to 2000–2001. The net present value per hectare of selectively harvesting and processing high-value clearwood from remnant western Queensland woodlands is found to be greater than clearing for grazing.

Evolution of Clay Minerals in a Chronosequence of Poldered Sediments Under the Influence of a Natural Pasture Development

AbstractClay minerals appear to change significantly under the influence of pasture development on poldered sediments in the Baie d'Authie area (Somme, France). Cores 40–90 cm deep from recent salt marsh sediments and poldered sediments developing grass pastures since 1737, 1575 and 1158 indicate that the natural mineral suite of kaolinite, mica, illite, and two disordered mixed-layered illite-smectite (I-S) phases common to the sedimentary input changes gradually but significantly in the materials. In the oldest, best-developed profile, there is a dominance of a disordered, illitic I-S in the humic upper part of the profile and a more abundant, more smectitic I-S mineral below. It appears that grass-derived humic materials tend to stabilize closed (collapsed) or illitic behavior in I-S clays. The natural evolution of the sediment (lower part of the profile) is towards a smectitic clay assemblage. Destruction of organic matter of the smectitic I-S minerals by oxidation indicates that this material can significantly modify the physical behavior of the clays keeping the structure open to polar molecules.

Management effects on soil carbon storage in New Zealand pastures

The amount of soil carbon is the net effect of carbon inputs and decomposition and is influenced by many factors including the level of herbage utilisation, root production, litter quality, soil fertility and soil moisture status. Long term experiments at Winchmore, in mid- Canterbury, show soil carbon levels increased after initial development, but after 50 years fertiliser input has had no net effect on soil carbon, while increasing the frequency of irrigation has actually resulted in lower soil carbon levels. Pasture development at Ballantrae , in the southern Hawke's Bay, has been associated with a decline in soil C levels, with the high fertility treatment having only slightly higher soil C than the treatment receiving a lower rate of fertiliser. At Tara Hills, in South Island semi-arid high country, increased stocking rate is associated with a decrease in soil C. Contrary to common perceptions increases in pasture and farm productivity do not necessarily result in increased soil carbon storage. Keywords: carbon, fer tiliser, grazing management, irrigation, soil organic matter

Grassland and Landscape Ecology : Ecological Functions of Riparian Buffers and Effects of Pasture Development on Riparian Ecosystem

Grassland and Landscape Ecology : Ecological Functions of Riparian Buffers and Effects of Pasture Development on Riparian Ecosystem

The impact of pasture development and grazing on water-yielding catchments in the Murray - Darling Basin in south-eastern Australia

Experiments conducted from November 1996 to June 2002 in adjacent small catchments near Wagga Wagga, New South Wales, compared the productivity and hydrology of a heavily fertilised (about 30 kg phosphorus/ha.year) Phalaris aquatica (phalaris) pasture with that of a lightly fertilised (about 14 kg phosphorus/ha every second year) native grassland that contained a mixture of C3 and C4 perennial grasses, dominantly C4 Bothriochloa macra (redgrass).In summer, the native catchment was dominated by C4 perennial grasses while the phalaris catchment was dominated by annual C4 weedy species. During the cooler months, the phalaris pasture contained higher proportions of Vulpia spp., and other less-desirable annual grasses. Throughout the experiment, the native catchment was dominated by redgrass, whereas in the phalaris catchment the persistence of phalaris declined. Redgrass became prominent on the more arid aspects of the phalaris catchment as the experiment progressed.Pasture production in the phalaris catchment was higher in most seasons than the native catchment, which resulted in an overall stocking rate advantage of about 80%. The productivity gain per unit of P input was 0.4 for the phalaris catchment compared with 1 for the native catchment, implying that phosphorus was applied to the phalaris catchment at an excessive rate.During wet periods the native catchment produced substantially more runoff than the phalaris catchment, while in dry times it developed substantially larger soil water deficits. Runoff from the phalaris catchment was higher in suspended and dissolved nitrogen and phosphorus than for the native catchment. Higher runoff from the native catchment combined with its drier soil profile in summer indicated that its deep drainage potential was less than in the phalaris catchment.

An evaluation of agroforestry systems as a rural development option for the Brazilian Amazon

In the Brazilian Amazon mass deforestation has resulted from a sequenceof road building, extractive logging, and pasture development during the pastthree decades. Ranchers have consolidated small agricultural holdings, pushingfarmers to move to forest frontiers or urban fringes, prompting furtherdeforestation and social instability. In response to this conversion ofAmazonian forests, the authors sought to identify both economically viable andmore sustainable development alternatives within the Brazilian state ofPara. There, local farmers of Japanese descent have developed a varietyof agroforestry systems in which 10 to 20 hectare (ha) fields yieldincomes comparable to 400 to 1,200 ha pastures. In addition, suchcrop fields generate substantially more rural employment per hathan do pastures. Ongoing forest conversion to pasture is clearly not a productof sound economic decision making. Improved land zoning and public policiescould favor agroforestry over further pasture expansion, stabilizing ruralpopulations while helping to conserve the Amazon's remaining forests.

Ryegrass Host Genetic Control of Concentrations of Endophyte-Derived Alkaloids.

Endophytic fungi in pasture grasses produce alkaloids which affect invertebrate and vertebrate herbivores. While the competence to produce an alkaloid is a property of the fungus, the host plant may moderate fungal activity. Host genetic influence on endophyte activity was studied in perennial ryegrass (Lolium perenne L.) infected with a common strain of Neotyphodium lolii (Latch, Christensen & Samuels) Glenn, Bacon & Hanlin. Progeny seedling families of a partial diallel cross and their 12 parent clones were compared in a glasshouse experiment. Peramine and ergovaline concentrations were determined by high pressure liquid chromatography (HPLC), and intensity of endophyte infection was determined by enzyme-linked immunosorbent assay (ELISA). Concentrations of peramine and ergovaline and the amount of endophyte mycelium in plants varied between families, consistently across two glasshouse cells and (for the HPLC data) two harvests. There was no indication of any maternal effects. Host genetic control was evident in significant general combining ability effects and smaller specific combining ability effects. Parent-progeny correlation coefficients were high, and narrow-sense heritability was estimated as 0.70, 0.72, and 0.58 respectively for ergovaline, peramine, and ELISA. Further analysis indicated little interaction between loci, and no directional dominance. The three traits were correlated, indicating that 41 and 65% of the genetically controlled variation in ergovaline and peramine concentrations, respectively, was a function of mycelial mass. However, there were departures from these relationships. Host plant selection may enable development of pastures with controlled low levels of toxic but ecologically beneficial endophyte metabolites.

Analyzing a forest conversion history database to explore the spatial and temporal characteristics of land cover change in Guatemala's Maya Biosphere Reserve

We analyzed forest clearing and regrowth over a 23-year time period for 21 forest concession and management units within the Maya Biosphere Reserve(MBR), Guatemala. The study area as a whole experienced a clearing rate of0.16%/year from 1974 through 1997. The overall clearing rate appears rather low when averaged over the entire study area over 23 years because most of the reserve was inaccessible. However, despite the granting of legal protection to the MBR in 1990, clearing rates continued to rise, with the highest rates occurring in the most recent time period in the analysis, 1995 to1997. Higher rates of clearing relative to regrowth occurred in newly established communities and in the Reserve's buffer zone, where the clearing of high forest was preferred for pasture development. Exploratory models were built and analyzed to examine the effects of various landscape variables on forest clearing. The different units in the analysis showed different relationships of forest clearing with variables such as forest cover type and distance to access(roads and river corridors). Where available, socio-economic household survey data helped to explain patterns and trends observed in the time series Landsat imagery. A strong relationship between forest clearing and distance to access was demonstrated. More clearing occurred further from roads during later time periods as farmers moved deeper into the forest to find land to clear. Communities inside the MBR that were less dependent on farming had forest clearing to regrowth ratios of one:one or less. These communities used fallow fields in greater proportions than communities in the Reserve's buffer zone. General trends in clearing by forest cover type suggest a preference for clearing high forest (bosque alto) types found on the higher elevation, better-drained soils, and fallow fields,and an avoidance of low-lying, seasonally flooded terrain(bajos). Satellite remote sensing observations of forest clearing and regrowth patterns can provide an objective source of information to complement socio-economic studies of the human driving forces in land cover and land use change.

Characteristics of major soils of Banni mudflat in arid western India and their relationship with topography

Studies on the soil properties of the apparently flat-lying, but salt-affected Banni mudflat region of arid Kachchh in western India revealed the influence of subtle topographic variations on soil texture and nature and distribution of salts. Six master pedons were investigated to an average depth of 150 cm. The pedons on the upper surfaces showed an abundance of fine sand and a gradual impoverishment of silt and clay, as also lesser amounts of salts in the profiles. Pedons on the successively lower surfaces showed more silt and clay contents, as well as higher amounts of salts. The findings helped to identify the areas suitable for pasture development in this vast degraded rangeland, and to suggest some management practices for improvement.