Critique of CANDE/AASHTO Soil Groups

2021 ◽  
Author(s):  
Amster Howard ◽  
Mark Gemperline
Keyword(s):  
Soil Groups

scholarly journals Characterization of Soil Carbon Stocks in the City of Johannesburg

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 83
Author(s):  
Kelebohile Rose Seboko ◽  
Elmarie Kotze ◽  
Johan van Tol ◽  
George van Zijl
Keyword(s):  
Bulk Density ◽  
Soil Depth ◽  
Soil Productivity ◽  
Rapid Urbanization ◽  
Organic C ◽  
C Stocks ◽  
Shallow Soils ◽  
Deep Soils ◽  
Soc Stocks ◽  
Soil Groups

Soil organic carbon (SOC) is a crucial indicator of soil health and soil productivity. The long-term implications of rapid urbanization on sustainability have, in recent years, raised concern. This study aimed to characterize the SOC stocks in the Johannesburg Granite Dome, a highly urbanized and contaminated area. Six soil hydropedological groups; (recharge (deep), recharge (shallow), responsive (shallow), responsive (saturated), interflow (A/B), and interflow (soil/bedrock)) were identified to determine the vertical distribution of the SOC stocks and assess the variation among the soil groups. The carbon (C) content, bulk density, and soil depth were determined for all soil groups, and thereafter the SOC stocks were calculated. Organic C stocks in the A horizon ranged, on average, from 33.55 ± 21.73 t C ha−1 for recharge (deep) soils to 17.11 ± 7.62 t C ha−1 for responsive (shallow) soils. Higher C contents in some soils did not necessarily indicate higher SOC stocks due to the combined influence of soil depth and bulk density. Additionally, the total SOC stocks ranged from 92.82 ± 39.2 t C ha−1 for recharge (deep) soils to 22.81 ± 16.84 t C ha−1 for responsive (shallow) soils. Future studies should determine the SOC stocks in urban areas, taking diverse land-uses and the presence of iron (Fe) oxides into consideration. This is crucial for understanding urban ecosystem functions.

scholarly journals Nematode Community-Based Soil Food Web Analysis of Ferralsol, Lithosol and Nitosol Soil Groups in Ghana, Kenya and Malawi Reveals Distinct Soil Health Degradations

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 101
Author(s):  
Haddish Melakeberhan ◽  
ZinThuZar Maung ◽  
Isaac Lartey ◽  
Senol Yildiz ◽  
Jenni Gronseth ◽  
...  
Keyword(s):  
Food Web ◽  
Health Management ◽  
Management Strategies ◽  
Soil Health ◽  
Principal Component ◽  
Trophic Group ◽  
Sub Saharan Africa ◽  
Soil Food Web ◽  
Soil Group ◽  
Soil Groups

Determining if the vast soil health degradations across the seven major soil groups (orders) of Sub-Saharan Africa (SSA) can be managed on the basis of a one-size-fits-all or location-specific approach is limited by a lack of soil group-based understanding of soil health degradations. We used the relationship between changes in nematode population dynamics relative to food and reproduction (enrichment, EI) and resistance to disturbance (structure, SI) indices to characterize the soil food web (SFW) and soil health conditions of Ferralsol, Lithosol and Nitosol soil groups in Ghana, Kenya and Malawi. We applied bivariate correlations of EI, SI, soil pH, soil organic carbon (SOC), and texture (sand, silt and clay) to identify integrated indicator parameters, and principal component analysis (PCA) to determine how all measured parameters, soil groups, and countries align. A total of 512 georeferenced soil samples from disturbed (agricultural) and undisturbed (natural vegetation) landscapes were analyzed. Nematode trophic group abundance was low and varied by soil group, landscape and country. The resource-limited and degraded SFW conditions separated by soil groups and by country. EI and SI correlation with SOC varied by landscape, soil group or country. PCA alignment showed separation of soil groups within and across countries. The study developed the first biophysicochemical proof-of-concept that the soil groups need to be treated separately when formulating scalable soil health management strategies in SSA.

scholarly journals Predicting Response of Southeast Texas Loblolly Pine to Fertilization

2001 ◽  
Vol 25 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Gregoire Ngono ◽  
R.F. Fisher
Keyword(s):  
Loblolly Pine ◽  
Critical Level ◽  
Nutrient Status ◽  
Integrated System ◽  
Vector Analysis ◽  
Diagnostic Tools ◽  
Southeast Texas ◽  
Pinus Taeda L ◽  
The Cost ◽  
Soil Groups

Abstract The Diagnosis and Recommendation Integrated System (DRIS), vector analysis, and critical level approaches are diagnostic tools commonly used for assessing nutrient status of trees by foliar analysis. This study evaluated the relative merits of the three approaches for identifying N and P deficiencies in stands of loblolly pine (Pinus taeda L.) in southeast Texas. Only 25% of the time did all three approaches select the same stands as N deficient, and only once did they agree that a stand was N sufficient. The three approaches agreed 25% of the time that stands were P deficient and 13% of the time that stands were P sufficient. No method was universally accurate in predicting response across soil groups. The critical level approach proved best for identifying all responsive sites, and it would be useful if the cost of fertilization was deemed low in comparison with the cost of lost growth when responsive sites are not fertilized. The DRIS approach failed to identify some responsive sites, but a high proportion of the sites it predicted would respond, did respond. It would be useful if the cost of fertilization were deemed high in comparison with the cost of lost growth when responsive sites are not fertilized. The vector analysis approach proved most useful because of its ability to predict response to N and P when added together. Soil group alone was a reasonable predictor of response to fertilization. South. J. Appl. For. 25(2):84–87.

scholarly journals Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture

2009 ◽  
Vol 44 (8) ◽  
pp. 996-1001 ◽  
Author(s):  
Pedro Rodolfo Siqueira Vendrame ◽  
Robélio Leandro Marchão ◽  
Osmar Rodrigues Brito ◽  
Maria de Fátima Guimarães ◽  
Thierry Becquer
Keyword(s):  
Total Carbon ◽  
Soil Macrofauna ◽  
Exchangeable Calcium ◽  
Exchangeable Ca ◽  
Calcium Magnesium ◽  
Distrito Federal ◽  
Calcium And Magnesium ◽  
Taxonomic Groups ◽  
The Relationship ◽  
Soil Groups

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.

CLAY MINERALS OF SOUTH AFRICAN SOIL GROUPS

Soil Science ◽  
1956 ◽  
Vol 81 (5) ◽  
pp. 399-414 ◽  
Author(s):  
C. R. VAN DER MERWE ◽  
H. HEYSTEK
Keyword(s):  
South African ◽  
Clay Minerals ◽  
African Soil ◽  
South African Soil ◽  
Soil Groups

Vulnerability of three spatially variable soil groups for solute leaching

1993 ◽  
Vol 7 (3) ◽  
pp. 235-247 ◽  
Author(s):  
J. H. M. Wösten ◽  
S. E. A. T. M. Van Der Zee
Keyword(s):  
Soil Groups ◽  
Solute Leaching

scholarly journals Growth and Grain Yield of Wheat in Relation to Differences in Soil Groups. II. The emergence and survival of tillers and their contribution to yield.

1992 ◽  
Vol 61 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Akiko SATO ◽  
Kazuhiro SUENAGA ◽  
Hiroyuki TAKADA ◽  
Kazumi KAWAGUCHI
Keyword(s):  
Grain Yield ◽  
Soil Groups

scholarly journals Effects of afforestation of agricultural land with grey alder (Alnus incana (L.) Moench) on soil chemical properties, comparing two contrasting soil groups

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Oļģerts Nikodemus ◽  
Dārta Kaupe ◽  
Imants Kukuļs ◽  
Guntis Brūmelis ◽  
Raimonds Kasparinskis ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Alnus Incana ◽  
Soil Groups

scholarly journals Kırsal Alanlarda Peyzaj Karakter Analizi “Kastamonu-Gölköy ve Yakın Çevresi Örneği”

2020 ◽  
Vol 8 (8) ◽  
pp. 1720-1725
Author(s):  
Sevgi Öztürk ◽  
Özge Vural ◽  
Kaan Meydan
Keyword(s):  
Rural Areas ◽  
Local Level ◽  
Landscape Management ◽  
Rural Settlements ◽  
Systems Software ◽  
Landscape Character ◽  
Large Soil ◽  
Soil Groups ◽  
Character Types

The planning and management of landscapes have been reviewed in the European Landscape Convention (ELC) and the need to identify landscape character areas has been emphasized. The determination of Landscape Character Types (LCT) at the local level is of great importance in order to ensure sustainable development in rural areas, correct management of the shelter values and determination of usage strategies. In this study, which aims to evaluate rural settlements with character determination and sustainability approach, the landscape variables of Kastamonu-Gölköy settlement and its immediate surroundings are mapped and analysed with Landscape Character Analysis (LCA) approach. For this purpose, the geology, large soil groups, geomorphology, slope groups, are a usage maps of the area were digitized with Geographic Information Systems software and character types were determined by synthesizing them. As a result of the study, 133 landscape character types were determined. It is thought that the acquired character types will serve as a base in rural planning and landscape management studies carried out at the national and local level and will contribute to the formation of landscape policies.

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