Soil physical property changes at the North American Long-Term Soil Productivity study sites: 1 and 5 years after compaction

2006 ◽  
Vol 36 (3) ◽  
pp. 551-564 ◽  
Author(s):  
Deborah S Page-Dumroese ◽  
Martin F Jurgensen ◽  
Allan E Tiarks ◽  
Felix Ponder, Jr. ◽  
Felipe G Sanchez ◽  
...  
Keyword(s):  
Bulk Density ◽  
North American ◽  
Soil Compaction ◽  
Soil Bulk Density ◽  
Water Infiltration ◽  
Soil Productivity ◽  
Soil Monitoring ◽  
The North ◽  
The Impact

The impact of forest management operations on soil physical properties is important to understand, since management can significantly change site productivity by altering root growth potential, water infiltration and soil erosion, and water and nutrient availability. We studied soil bulk density and strength changes as indicators of soil compaction before harvesting and 1 and 5 years after harvest and site treatment on 12 of the North American Long-Term Soil Productivity sites. Severe soil compaction treatments approached root-limiting bulk densities for each soil texture, while moderate compaction levels were between severe and preharvest values. Immediately after harvesting, soil bulk density on the severely compacted plots ranged from 1% less than to 58% higher than preharvest levels across all sites. Soil compaction increases were noticeable to a depth of 30 cm. After 5 years, bulk density recovery on coarse-textured soils was evident in the surface (0–10 cm) soil, but recovery was less in the subsoil (10–30 cm depth); fine-textured soils exhibited little recovery. When measured as a percentage, initial bulk density increases were greater on fine-textured soils than on coarser-textured soils and were mainly due to higher initial bulk density values in coarse-textured soils. Development of soil monitoring methods applicable to all soil types may not be appropriate, and more site-specific techniques may be needed for soil monitoring after disturbance.

scholarly journals A Comparison of Soil Compaction Associated with Four Ground-Based Harvesting Systems

2011 ◽  
Vol 28 (4) ◽  
pp. 194-198 ◽  
Author(s):  
Oscar Bustos ◽  
Andrew Egan
Keyword(s):  
Bulk Density ◽  
Forest Soils ◽  
Soil Compaction ◽  
Group Selection ◽  
Soil Bulk Density ◽  
Soil Productivity ◽  
Equipment Selection ◽  
Farm Tractor ◽  
Harvesting Systems

Abstract A study of soil compaction associated with four harvesting systems—a forwarder working with a mechanized harvester and a rubber-tired cable skidder, a farm tractor, and a bulldozer, each of them coupled with a chainsaw felling—was conducted in a group selection harvest of a mixed hardwood stand in Maine. The bulldozer system was associated with the highest percentage differences in soil bulk density measured in machine tracks (16.9%), trail centerlines (15.7%), and harvested group selection units (13.1%) versus adjacent untrafficked areas, whereas the forwarder system was associated with the lowest percentage differences in soil bulk density measured in machine tracks (3.5%), trail centerlines (1.2%), and harvested group selection units (6.3%) versus adjacent untrafficked areas. Results will help to inform loggers and foresters on equipment selection, harvest planning, and the conservation of forest soils and soil productivity.

Effect of combined soil water and external load on soil compaction

Soil Research ◽  
2011 ◽  
Vol 49 (2) ◽  
pp. 135 ◽  
Author(s):  
M. A. Hamza ◽  
S. S. Al-Adawi ◽  
K. A. Al-Hinai
Keyword(s):  
Bulk Density ◽  
Soil Water ◽  
Soil Compaction ◽  
External Load ◽  
Field Capacity ◽  
Infiltration Rate ◽  
Soil Bulk Density ◽  
Soil Strength ◽  
Water Infiltration ◽  
Soil Water Infiltration

Reducing soil compaction is now an important issue in agriculture due to intensive use of farm machinery in different farm operations. This experiment was designed to study the influence of combinations of external load and soil water on soil compaction. Four soil water levels were combined with four external loads as follows: soil water—air-dry, 50% of field capacity, field capacity, and saturation; external load using different-sized tractors—no load (0 kg), small tractor (2638 kg), medium tractor (3912 kg), and large tractor (6964 kg). Soil bulk density, soil strength, and soil water infiltration rate were measured at 0–100, 100–200, and 200–300 mm soil depths. The 16 treatments were set up in a randomised block design with three replications. Combined increases in soil water and external load increased soil compaction, as indicated by increasing soil bulk density and soil strength and decreasing soil water infiltration rate. There was no significant interaction between soil water and external load for bulk density at all soil depths, but the interaction was significant for soil strength and infiltration rates at all soil depths. The ratio between the weight of the external load and the surface area of contact between the external load and the ground was important in determining the degree of surface soil compaction. Least compaction was produced by the medium tractor because it had the highest tyre/ground surface area contact. In general, the effects of soil water and external load on increasing soil bulk density and soil strength were greater in the topsoil than the subsoil.

The North American long-term soil productivity experiment: Findings from the first decade of research

2005 ◽  
Vol 220 (1-3) ◽  
pp. 31-50 ◽  
Author(s):  
Robert F. Powers ◽  
D. Andrew Scott ◽  
Felipe G. Sanchez ◽  
Richard A. Voldseth ◽  
Deborah Page-Dumroese ◽  
...  
Keyword(s):  
North American ◽  
Soil Productivity ◽  
The North

Impacts of harvesting and postharvest treatments on soil bulk density, soil strength, and early growth of Pinus taeda in the Gulf Coastal Plain: a Long-Term Soil Productivity affiliated study

2006 ◽  
Vol 36 (3) ◽  
pp. 601-614 ◽  
Author(s):  
Mason C Carter ◽  
Thomas J Dean ◽  
Ziyin Wang ◽  
Ray A Newbold
Keyword(s):  
Bulk Density ◽  
Pinus Taeda ◽  
Weed Control ◽  
Tree Growth ◽  
Coastal Plain ◽  
Soil Compaction ◽  
Soil Bulk Density ◽  
Soil Strength ◽  
Gulf Coastal Plain ◽  
The Impact

At four sites in the Gulf Coastal Plain, mechanical whole-tree harvesting (MWT) removed more biomass and nutrients than hand-fell bole-only harvesting (HFBO). Soil compaction and loblolly pine (Pinus taeda L.) regeneration growth varied among sites. At one location, MWT increased soil bulk density by 0.1 Mg·m–3, from 1.14 to 1.24 Mg·m–3, with no effect on tree growth. At a second location, where bulk density increased by 0.1 Mg·m–3, from 1.41 to 1.51 Mg·m–3, pine growth was reduced significantly. Soil strength at 15–20 cm depth increased by 0.3–0.5 MPa at both locations. However, where MWT reduced pine growth, herbaceous weed control mitigated the effect. Fertilization with N and P, where P was limiting, increased pine growth irrespective of other treatments. Where P was not limiting, addition of a complete fertilizer reduced the mitigating effect of weed control. Bedding reduced soil compaction without improving early tree growth; however, bedding was not tested on the two sites where soil compaction appeared to be at critical levels. Broadcast burning increased survival but reduced pine growth irrespective of harvesting method. Our results suggest that the impact of intensive management on site productivity varies among sites, is potentially accumulative, and is subject to change over time.

scholarly journals The impact of COVID-19 Crisis on the Global Economy and the North American Hegemonic Cycle: A reading

2020 ◽  
Vol 27 (38) ◽  
pp. 9-28
Author(s):  
Patrícia Nasser de Carvalho ◽  
Elói Martins Senhoras
Keyword(s):  
North American ◽  
Global Economy ◽  
Negative Impact ◽  
The North ◽  
Theoretical Perspectives ◽  
Long Run ◽  
The Us ◽  
American Hegemony ◽  
The Impact

Based on the theorical framework that considers contextual and structural long-term perspectives of world hegemonic cycles and transitions of global powers, the aim of this reading is to critically analyze the ongoing and potential impact of the pandemic in the light of a conjunctural and historical perspective. The hypothesis is that although the COVID-19 crisis has already had deep negative impact on the global economy and represents a perfect storm for the US hegemony, seeing as the country is being challenged by many factors with strong magnitude and adverse effects, indeed it would not generate an immediate terminal crisis of the North American hegemony. Just in the long run the COVID-19 pandemic has the potential to trigger another world hegemonic power. The reading is based on the theoretical perspectives of world hegemonic cycles in international relations and is methodologically characterized as an explanatory and descriptive study and is built on a bibliographic review for the collection of theoretical and historical data.

Preaching and Sermons

2017 ◽  
Author(s):  
Robert H. Ellison
Keyword(s):  
Eighteenth Century ◽  
North Atlantic ◽  
Religious Revival ◽  
Early Nineteenth Century ◽  
Denominational Identity ◽  
The North ◽  
The North Atlantic ◽  
The One ◽  
The Impact

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.

scholarly journals Do Long-Term Natural Disasters Influence Social Trust? Empirical Evidence from China

2021 ◽  
Vol 18 (14) ◽  
pp. 7280
Author(s):  
Yao Li ◽  
Haoyang Li ◽  
Jianqing Ruan
Keyword(s):  
Natural Disasters ◽  
Natural Disaster ◽  
Social Trust ◽  
Geographical Location ◽  
Household Survey ◽  
Flood Frequency ◽  
Psychological Characteristics ◽  
The North ◽  
The Impact

The natural environment is one of the most critical factors that profoundly influences human races. Natural disasters may have enormous effects on individual psychological characteristics. Using China’s long-term historical natural disaster dataset from 1470 to 2000 and data from a household survey in 2012, we explore whether long-term natural disasters affect social trust. We find that there is a statistically significant positive relationship between long-term natural disaster frequency and social trust. We further examine the impact of long-term natural disaster frequency on social trust in specific groups of people. Social trust in neighbors and doctors is stronger where long-term natural disasters are more frequent. Our results are robust after we considering the geographical difference. The effect of long-term natural disasters remains positively significant after we divide the samples based on geographical location. Interestingly, the impact of long-term flood frequency is only significant in the South and the impact of long-term drought frequency is only significant in the North.

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