SOIL COMPACTING IMPACTS OF GRAZING IN MIXED PRAIRIE AND FESCUE GRASSLAND ECOSYSTEMS OF ALBERTA

1990 ◽  
Vol 70 (2) ◽  
pp. 157-167 ◽  
Author(s):  
M. A. NAETH ◽  
D. J. PLUTH ◽  
D. S. CHANASYK ◽  
A. W. BAILEY ◽  
A. W. FEDKENHEUER
Keyword(s):  
Light Intensity ◽  
Bulk Density ◽  
Penetration Resistance ◽  
Early Season ◽  
Late Season ◽  
Surface Moisture ◽  
Grassland Ecosystems ◽  
Mixed Prairie ◽  
Early Late

The impacts of long-term grazing on compaction were assessed in mixed prairie and fescue grassland ecosystems of Alberta. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Bulk density was measured with a surface moisture/density gauge and a combination moisture/density probe to 65 cm. Penetration resistance to 30 cm was measured with a cone penetrometer. Solonetzic soils were less sensitive to compaction under grazing than Chernozemic soils. Heavy intensity and/or early season grazing had greater impacts on compaction than light intensity and/or late season grazing. Under the former grazing regimes, bulk density increased to 7.5 cm at Kinsella and 65 cm at Stavely; penetration resistance increased to depths of 2.5 cm at Brooks, 15 cm at Kinsella, and 30 cm at Stavely. Heavy trampling versus regular grazing increased penetration resistance to depths of 30 and 10 cm under heavy intensity and/or early season and light intensity and/or late season grazing, respectively. Late season grazing at Brooks and light to moderate grazing at Stavely may be used as management models to reduce compaction under grazing. Trends were not as clear at Kinsella, but light June and autumn grazing had the least compacting effect. Key words: Compaction, grazing, rangelands, penetration resistance, bulk density

Impacts of grazing systems on soil compaction and pasture production in Alberta

2002 ◽  
Vol 82 (1) ◽  
pp. 1-8 ◽  
Author(s):  
N. T. Donkor ◽  
J. V. Gedir ◽  
R. J. Hudson ◽  
E. W. Bork ◽  
D. S. Chanasyk ◽  
...  
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Cervus Elaphus ◽  
Soil Compaction ◽  
Penetration Resistance ◽  
Moderate Intensity ◽  
Pasture Production ◽  
Grassland Ecosystems ◽  
Moist Condition ◽  
Grazing Systems

Livestock trampling impacts have been assessed in many Alberta grassland ecosystems, but the impacts of animal trampling on Aspen Boreal ecosystems have not been documented. This study compared the effects of high intensity [4.16 animal unit month per ha (AUM) ha-1] short-duration grazing (SDG) versus moderate intensity (2.08 AUM ha-1) continuous grazing (CG) by wapiti (Cervus elaphus canadensis) on soil compaction as measured by bulk density at field moist condition (Dbf) and penetration resistance (PR). Herbage phytomass was also measured on grazed pastures and compared to an ungrazed control (UNG). The study was conducted at Edmonton, Alberta, on a Dark Gray Luvisolic soil of loam texture. Sampling was conducted in the spring and fall of 1997 and 1998. Soil cores were collected at 2.5-cm intervals to a depth of 15-cm for measurement of bulk density (Dbf) and moisture content. Penetration resistance to 15 cm at 2.5-cm intervals was measured with a hand-pushed cone penetrometer. The Dbf and PR of the top 10-cm of soil were significantly (P ≤ 0.05) greater by 15 and 17% under SDG than CG, respectively, by wapiti. Generally, Dbf in both grazing treatments decreased over winter at the 0-7.5 cm and 12.5-15 cm depths, suggesting that freeze-thaw cycles over the winter alleviated compaction. Soil water content under SDG was significantly (P < 0.05) lower than CG. Total standing crop and fallen litter were significantly (P ≤ 0.05) greater in CG treatment than the SDG. The SDG treatment had significantly (P ≤ 0.05) less pasture herbage than CG areas in the spring (16%) and fall (26%) of 1997, and in the spring (22%) and fall (24%) of 1998, respectively. The SDG did not show any advantage over CG in improving soil physical characteristics and herbage production. Key Words: Bulk density, Cervus elaphus, moisture content, penetration resistance, pasture production

GRAZING IMPACTS ON INFILTRATION IN MIXED PRAIRIE AND FESCUE GRASSLAND ECOSYSTEMS OF ALBERTA

1990 ◽  
Vol 70 (4) ◽  
pp. 593-605 ◽  
Author(s):  
M. A. NAETH ◽  
R. L. ROTHWELL ◽  
D. S. CHANASYK ◽  
A. W. BAILEY
Keyword(s):  
Steady State ◽  
Grazing Intensity ◽  
Infiltration Rate ◽  
Infiltration Capacity ◽  
Early Season ◽  
Grazing Impacts ◽  
Infiltration Rates ◽  
Grassland Ecosystems ◽  
Mixed Prairie ◽  
And Control

Infiltration capacity is generally reduced with increased grazing intensity and reduced range condition, mainly through vegetation and litter removal, soil structure deterioration, and compaction. Only one study has documented the effect of grazing on Canadian rangelands, necessitating further investigation. In this study, impacts of long-term grazing on infiltration were assessed in mixed prairie and fescue grassland ecosystems of southern and central Alberta, Canada. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Ungrazed controls were evaluated at each site. Infiltration was measured with double ring infiltrometers. Heavy intensity and/or early season grazing had greater impact on infiltration than light intensity and/or late season grazing. In mixed prairie, initial and steady state infiltration rates in the control were 1.5 and 1.7 times higher, respectively, than those in the early season grazed treatment. In parkland fescue, initial rates were lowest in June grazed treatments and steady state rates were highest in light autumn grazed and control treatments. Initial infiltration rates in foothills fescue control and light grazed treatments were 1.5–2.3 times those in heavy and very heavy grazed treatments. Steady state rates were 1.5–2 times higher in light grazed and control treatments than in moderate, heavy, and very heavy grazed treatments. Key words: Infiltration, infiltration rate, grazing, rangelands

scholarly journals Calcium Sprays and Timing Affect Fruit Calcium Concentrations, Yield, Fruit Weight, and Cork Spot of `Anjou' Pears

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1037-1039 ◽  
Author(s):  
J.T. Raese ◽  
S.R. Drake
Keyword(s):  
Fruit Weight ◽  
Pyrus Communis ◽  
Early Season ◽  
Late Season ◽  
Four Seasons ◽  
Early Late ◽  
Low Rate

Calcium sprays (CaCl2, Mora-Leaf-Ca + Link Ca, or Stopit) increased fruit Ca concentrations and reduced the incidence of cork spot of `Anjou' pears (Pyrus communis L.) during four seasons. All Ca sprays increased yield relative to the control. All sprays resulted in some injury to leaves and fruit, but fruit was acceptable for marketing. At the low rate, Stopit sprays were the least injurious. Early season sprays, in June to July, produced less leaf and fruit injury than late-season sprays, in July to August, or early + late-season sprays. Early or late-season Ca sprays resulted in slightly larger fruit than early + late sprays. Either late or early + late-season sprays led to higher Ca concentrations in fruit cortex than early sprays.

Grazing impacts on soil water in mixed prairie and fescue grassland ecosystems of Alberta

1991 ◽  
Vol 71 (3) ◽  
pp. 313-325 ◽  
Author(s):  
M. A. Naeth ◽  
D. S. Chanasyk ◽  
R. L. Rothwell ◽  
A. W. Bailey
Keyword(s):  
Soil Water ◽  
Soil Surface ◽  
Canadian Prairies ◽  
Grazing Impacts ◽  
Growing Seasons ◽  
Grassland Ecosystems ◽  
Water Recharge ◽  
Grazing Intensities ◽  
Mixed Prairie

Reduced soil water under grazing is generally attributed to reduced infiltration as livestock trampling compacts the soil surface. Grazing can also have the opposite effect on soil water through reduced evapotranspiration when vegetation is removed. On the Canadian Prairies, grazing impacts on soil water have been assessed in short-term studies but impacts of long-term grazing have not been documented. In this study, impacts of long-term grazing on soil water were assessed in mixed prairie, parkland fescue grassland, and foothills fescue grassland ecosystems of southern and central Alberta. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Soil water was measured with a neutron probe to a depth of 1 m from April through October over three growing seasons. Normal patterns of soil water recharge in autumn and spring and soil water depletion in summer due to evapotranspiration were not altered by grazing. Fluctuations in soil water were most pronounced in the uppermost 30 cm but still evident in the 30- to 50-cm and 50- to 80-cm depth intervals. Heavy intensity and/or early season grazing had a greater impact on soil water than light intensity and/or late season grazing. Season of grazing affected soil water more under light than heavy grazing intensities. On most sampling dates, soil water in grazed treatments was lower than in the ungrazed control, particularly in the 30- to 50-cm and 50- to 80-cm depth intervals. Differences between the control and grazed treatments were least pronounced during the summer months with evapotranspiration depleting soil water reserves in all treatments. Key words: Soil water, grazing, rangelands, water uptake

scholarly journals Long-term cross-scale comparison of grazing and mowing on plant diversity and community composition in a salt-marsh system

2021 ◽  
Author(s):  
Qingqing Chen ◽  
Jan P. Bakker ◽  
Juan Alberti ◽  
Elisabeth S. Bakker ◽  
Christian Smit ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Community Composition ◽  
Plant Diversity ◽  
Livestock Grazing ◽  
Land Abandonment ◽  
Early Season ◽  
Late Season ◽  
Management Regimes ◽  
Over Time

AbstractLand abandonment is increasing in recent decades in Europe, usually accompanied by a decline in biodiversity. Whether livestock grazing and mowing can safeguard biodiversity across spatial scales in the long term is unclear.Using a 48-year experiment in a salt marsh, we compared land abandonment (without grazing and mowing) and seven management regimes including cattle grazing, early season mowing, late season mowing, both early and late season mowing, and grazing plus each of the mowing regimes on plant diversity at the local (i.e. plot) and landscape scales (i.e. across plots). Also, we compared their effects on community composition (both in identities and abundances) in time and space.Under land abandonment, plant diversity declined in the local communities and this decline became more apparent at the landscape scale, particularly for graminoids and halophytes. All management regimes, except the late season mowing, maintained plant diversity at these scales.Local plant communities under all treatments underwent different successional trajectories, in the end, diverged from their initial state except for that under grazing (a cyclic succession). Interannual composition change remained stable over time under land abandonment and grazing plus early season mowing. It increased over time under grazing and late season mowing, it increased in the second half of the experiment under other treatments. Vegetation homogenized in the landscape over time under land abandonment while vegetation was heterogeneous under all management regimes.Synthesis. Our experiment suggests that late season mowing may not be sustainable to conserve plant diversity in salt marshes. Other management regimes can maintain plant diversity across scales and vegetation heterogeneity in the landscape in the long term, but local community composition may change over time.

The long-term effects of silvicultural thinning and partial cutting on soil compaction in red pine (Pinus resinosa Ait.) and northern hardwood stands in the northern Great Lakes Region of the United States

2008 ◽  
Vol 88 (5) ◽  
pp. 849-857 ◽  
Author(s):  
R A Tarpey ◽  
M F Jurgensen ◽  
B J Palik ◽  
R K Kolka
Keyword(s):  
Hydraulic Conductivity ◽  
Bulk Density ◽  
Soil Compaction ◽  
Basal Area ◽  
Penetration Resistance ◽  
Saturated Hydraulic Conductivity ◽  
Red Pine ◽  
North Central ◽  
Soil Penetration Resistance

Periodic silvicultural thinnings (23.0, 27.6, 32.1 m2 ha-1 residual basal area) in a red pine stand growing on a sandy soil in north-central Minnesota over a 57-yr period increased soil compaction as the intensity of the thinning treatment increased. Of the three different methods used to measure soil compaction (bulk density, penetration resistance, and saturated hydraulic conductivity), saturated hydraulic conductivity was the most sensitive, decreasing by 60% in the 23.0 m2 ha-1 basal area thinning treatment, as compared with the uncut control. Soil bulk density measurements were more variable, but generally increased with increased thinning intensity. Few differences in soil penetration resistance were found among the three thinning treatments. In contrast, no evidence of soil compaction was detected in a northern hardwoods stand growing on a rocky loam soil in north-central Wisconsin that had three thinning treatments (13.8, 17.2, 20.6 m2 ha-1 residual basal area), a two- stage shelterwood harvest, and a 20-cm-diameter limit cut over a 50-yr period. With the increased demand for forest products, fuel reduction operations in high fire-risk stands, and biomass removal for energy production, more information is needed on the impact of multiple stand entries on soil compaction, and if compaction occurs, whether it will affect long-term soil productivity. Key words: Soil physical properties, bulk density, soil penetration resistance, hydraulic conductivity

Long-term patterns and feeding sites of southern green stink bug (Hemiptera: Pentatomidae) in Hawaii macadamia orchards, and sampling for management decisions

2007 ◽  
Vol 97 (6) ◽  
pp. 569-575 ◽  
Author(s):  
M.G. Wright ◽  
P.A. Follett ◽  
M. Golden
Keyword(s):  
Sampling Procedure ◽  
Tree Canopy ◽  
Stink Bug ◽  
Early Season ◽  
Late Season ◽  
Feeding Sites ◽  
Southern Green Stink Bug ◽  
Green Stink Bug ◽  
Macadamia Nuts

AbstractSouthern green stink bug (Nezara viridula, Hemiptera: Pentatomidae) is a pest of macadamia nuts, causing pitting to kernels by feeding. In spite of its pest status, many aspects of the ecology of this insect in macadamia orchards are poorly understood. This study analyzes long-term N. viridula damage to macadamia nuts and investigates the extent to which damage to nuts occurs in the tree canopy, prior to nut-drop. We show that there are distinct seasonal peaks in damage detected after harvest and that, over six years of data collection, mean damage levels were fairly low, albeit with spikes in damage levels recorded. Sampling nuts at peak harvest periods from different strata in the trees and from the ground showed that incidence of damaged nuts within the canopy was typically half as high as on the fallen nuts. Damage to fallen nuts may have occurred prior to nut-drop, and continued to accumulate after nut-drop. These results show that management of N. viridula within macadamia canopies, as opposed to only on fallen nuts, is important. A sampling procedure and predictive model for estimating late-season damage based on early-season damage samples is provided. The model uses January and March damage measurements (based on samples with set level of accuracy), mean temperature and month of the year for which damage is predicted. Early-season damage of 6–10% predicts late-season damage levels that should justify N. viridula suppression based on the nominal threshold (13% damage) used by kernel processors to reject nuts based on damage.

Effect of reduced phosphorus fertilizer on early/late season rice yield in South China

2010 ◽  
Vol 18 (3) ◽  
pp. 606-610 ◽  
Author(s):  
Wu LI ◽  
Xiao-Juan YANG ◽  
Xiang-Ru TANG ◽  
Guo-Xi LI ◽  
Guo-Wei PENG ◽  
...  
Keyword(s):  
South China ◽  
Rice Yield ◽  
Phosphorus Fertilizer ◽  
Late Season ◽  
Early Late
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