Effect of livestock grazing on physical properties of a cracking and self-mulching Vertisol

2002 ◽  
Vol 42 (2) ◽  
pp. 129 ◽  
Author(s):  
G. Taddese ◽  
M. A. Mohamed Saleem ◽  
W. Ayalneh
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Addis Ababa ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Control Treatment ◽  
Soil Matrix ◽  
Heavy Grazing ◽  
The Impact ◽  
Grazing Pressures

The impact of grazing on physical properties of Vertisol was studied from 1996 to 2000 in the Ethiopian highlands. The study was conducted at 2 sites with 0–4 and 4–8% slopes at Tero Jemjem watershed in Ginchi, 80 km west of Addis Ababa. The objective of the study was to compare selected soil physical properties at different grazing pressures and slopes. The stocking rate was moderate grazing 1.8 animal-unit months per hectare (1.8 AUM/ha), heavy grazing 3.0 AUM/ha and a control treatment with no grazing. The result showed that heavy grazing pressure removed grass cover, which consequently enhanced soil cracking. Effect of livestock trampling on soil resistance to penetration (indicated by penetrometer readings) was higher in the heavily grazed plots than in non-grazed plots. Penetrometer readings were influenced by soil moisture content. Low moisture content was observed in the heavily grazed plots at both sites. The infiltration of accumulated water to the soil matrix was lower in heavily grazed plots.

scholarly journals The Selection, Testing, and Application of Ecological Bioindicator Birds: A Case Study of the Bale Mountains, Southeast Ethiopia

1970 ◽  
Vol 11 (2) ◽  
pp. 187-208
Author(s):  
Asefa Addisu ◽  
Mengesha Girma
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Sampling Period ◽  
Ecological Monitoring ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Bioindicator Species ◽  
Heavy Grazing ◽  
Southeast Ethiopia ◽  
Selection Testing

The interest in using ecological bioindicators - species or higher taxa, whose presence/absence or abundance reflect the abiotic or biotic state of an ecosystem - as cost-effective means of ecological monitoring has been globally increasing. The main aim of this study was to assess if such ecological bioindicator species could be identified within Afromontane grassland avifauna that would be used for monitoring the effects of livestock grazing on ecosystem in the Bale Mountains of Ethiopia. We collected data on birds and vegetation structure along 14 transects each in the light (protected) and heavy (unprotected) grazing sites in June 2014 (referred to as the first sampling period) and in December 2014 (the second sampling period). Then, we (i) initially identified potential bioindicator species for the light grazing site, based on data collected during the first sampling period; (ii) examined relationships between abundance of these bioindicators and level of grazing pressure; (iii) tested the consistency of those initially selected bioindicator species, based on independent data collected during the second sampling period. We used the Indicator Value (IndVal) Analysis method to identify bioindicator species for the light grazing site. Species with significant IndVal>60% were considered as potential bioindicator for the site compared to the heavy grazing site. Six species were initially identified as potential bioindicators from the first sampling period dataset, and four of these species were again consistently identified from the second sampling period. Furthermore, abundance of the bioindicators had significantly declined with increasing grazing pressure, but positively correlated with four habitat variables (i.e. heights of shrub, herb and grass, and cover of shrub). These findings suggest that those consistently identified four species represent suite of reliable bioindicators that can successfully be used for monitoring of changes in habitat structure in the site. Recommendations on how to apply these findings for ecological monitoring are provided.

Effect of grazing intensity and number of grazings on herbage production and seed yields of Trifolium subterraneum, Medicago murex, and Ornithopus compressus

1994 ◽  
Vol 34 (2) ◽  
pp. 181 ◽  
Author(s):  
DJ Conlan ◽  
BS Dear ◽  
NE Coombes
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Grazing Intensity ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Early Spring ◽  
Pasture Legumes ◽  
Heavy Grazing ◽  
Ornithopus Compressus ◽  
The Impact

The impact of grazing intensity and number of grazings was assessed on the growth and seed production of 5 annual pasture legumes [Trifoliunz subterraneum var. subterraneum cv. Karridale, var. brachycalycinum cv. Clare, var. yanninicum cv. Trikkala; Medicago murex (murex medic) cv. Zodiac; Ornithopus compressus L. (yellow serradella) cv. Avila]. There were 7 grazing treatments: an ungrazed control; and 2 grazing intensities (light and heavy), each for 3 periods of grazing (winter, winter-early spring, winter-late spring). Tethered sheep in small experimental plots were used to provide controlled herbage removal across all cultivars through winter and winter-spring grazing. This grazing system resulted in significantly different levels of herbage being present in the light and heavy grazing treatments following each grazing period. Grazing had variable effects on seed production: <35% increase for Trikkala, and no significant effect for Karridale. Both cultivars continued growth and seed production late in the season after grazing pressure was removed on 8 November. Seed yield of Clare was reduced by 46-49% by heavy grazing treatments. Seed yield of murex medic was not significantly affected by grazing, while that of serradella was reduced by 30-55% by grazing late in the season. The seed yield responses show that cultivar and species responses to grazing may be highly variable. Under favourable spring conditions, Trikkala, Karridale, and murex medic can be grazed heavily until late in the season without adversely affecting seed yield, whilst Clare and Avila cannot.

Effects of sheep grazing Astrebla grassland in central western Queensland. 1. Effects of grazing pressure and livestock distribution

1980 ◽  
Vol 31 (4) ◽  
pp. 797 ◽  
Author(s):  
DM Orr
Keyword(s):  
Basal Area ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Plant Responses ◽  
Sheep Grazing ◽  
Regular Grid ◽  
Heavy Grazing ◽  
Grazing Pressures ◽  
Light Medium

The effects of grazing pressure on plant responses and livestock distribution in Astrebla grassland were determined from paddocks subject to commercial grazing by sheep at light, medium or heavy grazing pressure. Increased grazing pressure reduced the projected foliage cover of Astrebla spp., the basal area of which was similar under light and medium grazing pressure, and was reduced under heavy grazing pressure. Differences in the density and size of Astrebla spp. tussocks were apparent under the three grazing pressures. Other perennial grasses, notably Aristidu latifolia and A. leptopoda, were most frequent under light grazing pressure. Numerical classification of the sampling sites, which were arranged on a regular grid, allowed the grazing pattern to be established. Heavy utilization was shown to be associated with wind direction, shade availability and watering facilities.

scholarly journals Carabid (Coleoptera) assemblages in the Scottish uplands: the influence of sheep grazing on ecological structure

2006 ◽  
Vol 17 (3) ◽  
Author(s):  
Lorna Cole ◽  
Meg Pollock ◽  
Duncan Robertson ◽  
John Holland ◽  
David McCracken
Keyword(s):  
Ground Beetle ◽  
Grazing Intensity ◽  
Diversity Indices ◽  
Grazing Pressure ◽  
Assemblage Structure ◽  
Livestock Grazing ◽  
Pitfall Trapping ◽  
Agricultural Policy Reform ◽  
Intensively Managed ◽  
The Impact

As a result of the European Community Common Agricultural Policy reform in 2005 it is predicted that livestock grazing in the Scottish uplands will become less intensive. At each of two upland research centres, two large (>40ha) plots were established to investigate the relationship between grazing intensity in the Scottish uplands and biodiversity. One plot was grazed intensively by sheep while the otherwas grazed extensively. Ground beetleswere sampled by pitfall trapping to determine the influence of grazing pressure on the ecologicalmake-up of ground beetle assemblages. Grazing intensity did not significantly influence carabid diversity. However, grazing intensity, altitude and moisture did influence the carabid ecological assemblage structure at both locations. Large flightless Carabus species were more abundant in extensively managed plots than intensively managed plots at both locations. It is likely that these long-living, relatively immobile beetles were favoured by the greater stability of the vegetation structure in the extensively grazed plots. Monitoring the ecological assemblage structure provides a more sensitive approach than diversity indices when comparing the impact of grazing and agricultural management but is also robust enough to allow direct comparisons between different geographical locations.

scholarly journals Effects of Amylose-To-Amylopectin Ratios on Binding Capacity of DDGS/Soy-Based Aquafeed Blends

2016 ◽  
Vol 5 (5) ◽  
pp. 43 ◽  
Author(s):  
Ferouz Ayadi ◽  
Kurt A. Rosentrater ◽  
K. Muthukumarappan ◽  
S. Kannadhason
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Water Solubility ◽  
Binding Capacity ◽  
Sole Source ◽  
Expansion Ratio ◽  
Process Conditions ◽  
Fish Feed ◽  
Seafood Products ◽  
The Impact

Demands for seafood products are steadily increasing. Alternative protein sources are required to compensate for enormous amounts of fishmeal that is needed for global seafood production. Starch is a food polymer that can be added to fish feed formulations to enhance binding and expanding capabilities of extrudates. Floatability, a key factor for most aqua feeds, can be optimized by the addition of certain starch sources. Six ingredient blends with a similar protein content (~32.5%) containing two starch sources, Hylon VII (containing 70% amylose, 30% amylopectin) or Waxy I (containing 0% amylose, 100% amylopectin), 20% distillers dried grain with solubles (DDGS), and 15, 25, and 35% moisture content were used along with appropriate amounts of soybean meal, menhaden fishmeal, whey, vitamin and mineral mix to investigate nutritionally-balanced feeds for Nile tilapia (Oreochromis niloticus L.). The blends were processed using a laboratory single-screw extruder with varying temperature settings (90-90-90°C, 100-120-120°C, and 100-120-140°C), screw speeds (100, 120, and 140 rpm), and length/diameter ratio (3.4, 6.6, 9.2) of the die. Extensive analyses of expansion ratio (ER), unit density (UD), sinking velocity (SV), and pellet durability indices (PDI), water absorption (WAI) and water solubility indices (WSI) were conducted to evaluate the effects of the two starch sources on extrudate binding and floating capacity. By varying process conditions, significant differences (P>0.05) among the blends were detected for all extrudate physical properties. Significantly higher values for ER, UD, and PDI were achieved by using the Waxy I starch source, while values for SV and WAI decreased. For WSI no significant differences were detected. Increasing the moisture content from 15-35% resulted in a significant increase in ER, WAI, and PDI and a significant decrease in UD. WSI showed no clear pattern in changes. The impact of different amylopectin to amylose ratio, temperature and moisture content on extrudate stability, cohesion and physical properties was demonstrated in this study. All formulations yielded viable extrudates while the blends with the amylopectin as the sole source of starch resulted in higher quality extrudates.

The impact of heavy grazing on burrow choice in the pygmy bluetongue lizard, Tiliqua adelaidensis

2011 ◽  
Vol 38 (4) ◽  
pp. 299 ◽  
Author(s):  
Melissa Pettigrew ◽  
C. Michael Bull
Keyword(s):  
Native Species ◽  
Negative Impact ◽  
South Australia ◽  
Grazing Intensity ◽  
Grazing Pressure ◽  
Natural Ecosystems ◽  
Native Grasslands ◽  
Heavy Grazing ◽  
Microhabitat Structure ◽  
The Impact

Context Grazing pressure has directly altered and indirectly influenced natural ecosystems worldwide, and has affected and displaced many native species. The endangered pygmy bluetongue lizard Tiliqua adelaidensis is endemic to the mid-north of South Australia. It inhabits remnant native grasslands where it is reliant on the presence of natural spider burrows constructed by lycosid and mygalomorph spiders as refuge sites. These lizards spend the majority of the day associated with their burrow either in the burrow itself or basking at its entrance. The remnant native grasslands of South Australia have endured 200 years of agricultural changes and the introduction of domestic stock has meant that grazing pressure has substantially increased. The vegetation around a burrow is considered to be important in providing shelter for the lizard. However, too much vegetation may reduce basking opportunities and visibility of prey. Stock grazing has been maintained on the majority of sites that contain pygmy bluetongue populations and it is presumed that the lizards can tolerate some form of grazing. However, the level of grazing intensity directly influences the vegetation structure that surrounds the lizard burrows. Aims We aimed to investigate the consequences of severe grazing pressure on the choice of burrows by lizards, and on their burrow related behaviour. Methods We simulated heavy grazing pressure by manually removing aboveground vegetation in the field in replicated quadrats that contained artificial burrows, and by providing bare substrate in half of experimental enclosures in the laboratory. Key results In the field, lizards only occupied the artificial burrows in control quadrats, where vegetation had been left intact. In the laboratory, lizards that occupied both burrows basked for longer at the burrow entrance where vegetation was present. Conclusions Heavy grazing management that results in the majority of vegetation being removed could have a negative impact on pygmy bluetongue lizard recruitment and sustainability. Implications Grazing regimes should be carefully monitored to consider the needs of species that rely heavily on microhabitat structure for their persistence. For the endangered pygmy bluetongue lizard, heavy grazing should be avoided to promote amounts of vegetation suitable to sustain viable populations.

scholarly journals Impact of Livestock Grazing on the Floristic Composition: A Case Study of the Mount of Tessala, Western Algeria

2014 ◽  
Vol 3 (3) ◽  
pp. 186-200
Author(s):  
Cherifi Kouider ◽  
Zoheir Mehdadi ◽  
Ali Latreche ◽  
Zouaoui Hazem ◽  
Wael El Zerey
Keyword(s):  
Species Richness ◽  
Floristic Composition ◽  
Livestock Grazing ◽  
Western Algeria ◽  
Components Analysis ◽  
Palatable Species ◽  
The Impact ◽  
North And South ◽  
Grazing Pressures

The present work focuses on evaluating the impact of livestock grazing on the floristic composition in the mount of Tessala (Western Algeria). Phytoecological surveys were carried out at seven stations around north and south slopes of the mount. The obtained results through Principal Components Analysis (PCA) indicated the impact of man and herd on the floristic composition of sampling stations. Indeed, stations where grazing is low, have greater species richness marked by the strong presence of palatable species, unlike stations under permanent grazing, characterized in particular by the appearance of non-palatable species. Moreover, we note the dominance of therophytes at all stations not only due to grazing pressures but also to drought in the study area. DOI: http://dx.doi.org/10.3126/ije.v3i3.11078 International Journal of Environment Vol.3(3) 2014: 186-200

scholarly journals Physical Properties of Homogeneous Particleboard based on Acacia Tree and Polyurethane Adhesive as a Resins

2019 ◽  
Vol 8 (6) ◽  
pp. 3382-3387
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Water Absorption ◽  
High Water ◽  
Raw Material ◽  
Paraffin Wax ◽  
Water Repellent ◽  
Industry Standard ◽  
The Impact ◽  
Acacia Tree

The formaldehyde-based adhesives have always been chosen for manufacturer in the making of particleboard because of the cost. However, it has low moisture resistance and high water absorption. At the same time, formaldehyde-based adhesive also produced gaseous emission that can cause cancer and bronchial health. Meanwhile, the high water resistance, low moisture content and healthy to the human body nowadays becomes most important issues in the making of furniture for market. This research was discusses on the ability of Acacia tree as raw material and polyurethane (PU) as an adhesive for making the homogeneous particleboard. The aim of this research isto looking the impact of using different particle sizes from Acacia tree to the physical properties of the end product. This study also focuses on the potential of paraffin wax as a water repellent agent. The testing of physical properties was includes the thickness swelling (TS) testing, moisture content (MC), density and water absorption (WA testing). The size of Acacia particle was varied from x<2mm, 4mm>x>2mm and x>4mm. All particleboards produced was achieve the range of medium density according to the Japan Industry Standard (JIS). The results have shown that the value of the density and the particle size was influenced the result especially for the physical properties. From this research it is proved that the PU as a resin and sawdust of acacia tree with some specific size can be a good binder and material for the particle board industries in future. The paraffin wax also showed a great potential as a water repellent agent based on the reduction of water absorption of the particleboard. The particleboard with sizes between 2mm to 4mm proves better results compared to the smaller or bigger sizes of particle.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

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