Assessing physical quality of plastic soils of differing mineralogy and pre-stress history using mechanical parameters. I. Saturated compression tests

2003 ◽  
Vol 83 (1) ◽  
pp. 45-63 ◽  
Author(s):  
P. J. Joosse ◽  
R. A. McBride

The comparison of selected soil mechanical parameters measured on plastic soils under remoulded and structurally intact conditions may provide an opportunity to assess soil structural quality on a regional or even broader scale. This study was conducted to determine: (i) if existing pedotransfer functions developed for southwestern Ontario soils could be used outside this physiographic region, and (ii) if key mechanical parameters were sensitive to a range of land use conditions that are likely to influence soil structural quality. Soil profiles were sampled in natural (forested or grassland), agricultural and pipeline workspace areas (land use variable) located in southwestern Ontario, eastern Ontario, Alberta and Texas (mineralogy variable). Slurry consolidation and uniaxial compression tests were conducted on remoulded and structurally intact samples, the resulting void ratio-log stress [e(logσ')]data were fitted to linear or nonlinear model equations, respectively, and several key mechanical parameters were derived. The effective stresses at the liquid and plastic limits could not be adequately estimated for soils with smectitic mineralogy using existing pedotransfer functions because of the absence of a significant relationship with organic carbon content. The difference between void ratio intercepts for remoulded and structurally intact soils (e*1kPa–e0) was found to be a suitable indicator of physical soil quality because of the convergence of remoulded and structured compression lines in e(logσ') co-ordinates. Severely overconsolidated soils were identified when the (e*1kPa–e0) variable exceeded 0.40. This threshold also corresponded to soil conditions that could limit plant growth. Key words: Compression, consolidation, pedotransfer function, soil quality, Atterberg limits, remoulded, structured, pipeline, woodland

2010 ◽  
Vol 27 ◽  
pp. 121-129 ◽  
Author(s):  
W. Rieger ◽  
F. Winter ◽  
M. Disse

Abstract. Distributed flood control measures such as land-use changes or differing soil tillage practices which affect the runoff generation process, are hard to simulate physically based due to a high degree of uncertainty with regard to soil parameterisation. In this study the physically based rainfall runoff model WaSiM-ETH (Version 8.4.2) was used with a multi-layered vegetation and soil parameterisation. The modelling area was the meso-scaled and rurally characterised Windach catchment. In addition, soil measurement datasets were compared to demonstrate the uncertainties in soil parameterisation of physically based models. The datasets were gained from the hillslope scale at the Scheyern research farm with similar soil conditions to the Windach catchment. While parameterising and calibrating the model, seven different pedotransfer functions were used with strong influence on the simulated hydrographs. The differing bulk densities of soils depending on land-use and soil tillage must be taken into consideration due to their high impact on modelling results, and they also offer a comprehensive way to model distributed flood control measures. These measures have noticeable effects on flood events under HQ10, especially if the land-use type which is affected by the distributed flood control measure is the dominating land-use form in the catchment area. To account for the variability of soils in the investigation area of Scheyern, different approaches were applied to estimate soil hydraulic properties and saturated hydraulic conductivity, and were compared to field measurements.


Author(s):  
Hamza Haruna ◽  
Galal H.G. Hussein ◽  
Mohammed B

Soil is a living and dynamic natural reservoir and source of plant nutrients that play numerous key roles in terrestrial ecosystems. This study investigated the impact of three adjacent land use systems (Acacia senegalensis plantation (ACP), pilostigma raticulatum plantation (PRP) and Ground nut field (GNF) on selected soil physical quality indicators in a Northern Nigeria semi- arid Savanna. Minimum data set for assessing soil quality (Prime quality agricultural land) in this study include bulk density, organic carbon content, total nitrogen, carbon stock, available phosphorus and pH values obtained from DRMCC research field. Mean values of the data set were arranged and scored to obtain totals among the minimum data set (MDS). Soil quality is considered a key element for evaluating the sustainability of land management practices. Data generated were analyzed using ANOVA and significant means were determined using Duncan multiple range test (DMRT). ACP had significantly higher organic carbon content (9.37 gkg-1) and lower bulk density (2.16 gkg-1) than pilostigma and GNF respectively. The lower bulk density (ρb) and high organic carbon in ACP might be due to high leaf shading by acacia while the lower bulk density in ground nut field aided by trampling induced compaction resulted in its high relative field capacity (RFC), permanent wilting point (PWP) and micro-p ore spaces (PMIC) tillage in ground nut field created loose soil in the plough layer (<20 cm) which turn out to its low bulk density (ρb). Acacia plantation contained highest total nitrogen value (1.23 gkg-1); perhaps resulting Acacia leaf litter is known to have a high decomposition rate. Pilostigma plantation contained (1.22 gkg-1) nitrogen, while the least nitrogen content was obtained under ground nut field. On scoring the land use types and depth against the minimum data set, the least total was that under acacia plantation, followed by pilostigma plantation then ground nut field. Therefore, soils under acacia plantation were ranked best quality (SQ1) for cultivation purposes at 0-10 cm, followed by pilostigma land use type that were ranked SQ2. Ground nut field soils were ranked least (SQ6) in quality for use in crop production at depth of 10-20 cm.


2002 ◽  
Vol 39 (2) ◽  
pp. 388-398 ◽  
Author(s):  
M W Bo ◽  
V Choa ◽  
K S Wong

To understand the deformation of ultrasoft soil in a viscous state, compression tests were carried out using a small-scale consolidometer equipped with pore-pressure transducers at three locations. Deformation behavior was monitored with both settlement and pore-pressure measurements. The transitional points from slurry to soil were determined from the settlement rate, change in void ratio, change in permeability, and pore-pressure dissipation. It was found that the transitional void ratio determined from the settlement rate is smaller than that determined from the commencement of pore-pressure dissipation. The transitional void ratio varied slightly for samples with different initial moisture contents determined based on pore-pressure considerations. The variation was due to the difference in sample thickness which affected the initiation of pore-pressure dissipation at the bottom of sample. In reality, the void ratio at transition could be larger than those determined from both settlement and pore pressure.Key words: ultrasoft soil, deformation, compression, pore pressure, permeability.


2014 ◽  
Vol 18 (9) ◽  
pp. 3763-3775 ◽  
Author(s):  
K. Meusburger ◽  
G. Leitinger ◽  
L. Mabit ◽  
M. H. Mueller ◽  
A. Walter ◽  
...  

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.


2021 ◽  
Vol 13 (15) ◽  
pp. 8332
Author(s):  
Snežana Jakšić ◽  
Jordana Ninkov ◽  
Stanko Milić ◽  
Jovica Vasin ◽  
Milorad Živanov ◽  
...  

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.


2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.


2020 ◽  
Vol 5 (1) ◽  
pp. 94-106
Author(s):  
Evgeny Abakumov ◽  
Evgeniya Morgun ◽  
Alexandr Pechkin ◽  
Vyacheslav Polyakov

AbstractThe post-anthropogenic and soil cover transformations of former agricultural soils on the abandoned lands in the Russian Arctic territory are poorly investigated due to the active growth of the city complexes and increasing area occupied by agricultural lands. That is lead to an increase in the area of the arable lands surrounding the polar urbanized territories. Today, most of that land allocated for agricultural needs has been abandoned or affected by other types of land use. This study aimed to investigate the abandoned lands surrounding some of the settlements in the central part of the Yamal region. The soil diversity, morphology, and chemical and agrochemical properties were investigated with special reference to the specific transformations that occur to fallow lands under permafrost-affected cryogenic-ecosystem conditions. Analysis of data show that these soils are characterized by features relating to both, previous (and existing), anthropogenic impacts and natural processes such as cryogenic mass transfer. The degradation of the arable humus-enriched horizon was not as pronounced as it has been in more humid boreal environments over recent decades. The organic carbon content in topsoil depends on the land use and varied considerably among the soil types. The former arable topsoil horizon has been stable over time in terms of its morphological features and agrochemical state. Despite the high soil acidity levels, thenutrient content in the anthropogenically impacted soils was still high, even though being abandoned for 20 years.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 353
Author(s):  
Ya-Wen Chiueh ◽  
Chih-Hung Tan ◽  
Hsiang-Yi Hsu

In the face of climate change, extreme climates are becoming more frequent. There were severe droughts in Taiwan in 2020, 2014–2015, and 2002. In these years, the paddy fields were kept fallow to save water and transfer agricultural water to non-agricultural use. On the other hand, with global warming, the existence of paddy fields may be one of the natural solutions to regional temperature mitigation. This study used remote sensing to quantify the difference in temperature between paddy fields and urban areas. The result of overall surface temperature deductive analysis revealed that the temperature in the whole Taoyuan research area was 1.2 °C higher in 2002 than in 2003 because of fallowing of the paddy field, while in the Hsinchu research area, it was 1.5 °C higher in 2002 than in 2003, due to the same reason described above. In terms of the difference in land use, for the Hsinchu research area, the surface temperature deductive result showed that the average paddy field temperature in 2002 was 22.3 °C (sample area average), which was 7.7 °C lower than that of the building and road point and 4.3 °C lower than that of the bare land point. The average paddy field temperature in 2003 was 19.2 °C (sample area average), which was 10.1 °C lower than that of the building and road point and 8.3 °C lower than that of the bare land point. Then this study evaluated the economic valuation of the paddy field cooling effect using the contingent valuation method. Through the paddy field cooling effect and in the face of worsening extreme global climate, the willingness to pay (WTP) of the respondents in Taiwan for a decrease of 1 °C with regard to the regional microclimate was evaluated. It was found that people in Taiwan are willing to pay an extra 8.89 USD/per kg rice/year for the paddy for a decrease in temperature by 1 °C in the regional microclimate due to the paddy field. Furthermore, this study applied the benefits transfer method to evaluate the value of a decrease of 1 °C in the regional microclimate in Taiwan. The value of a decrease of 1 °C in the regional microclimate in Taiwan is 9,693,144,279 USD/year. In this regard, the economic value of 1 °C must not be underestimated. In conclusion, more caution is needed while making decisions to change the land use of paddy fields to other land uses.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 358
Author(s):  
Elena Gagnarli ◽  
Giuseppe Valboa ◽  
Nadia Vignozzi ◽  
Donatella Goggioli ◽  
Silvia Guidi ◽  
...  

Sustainable agriculture largely depends on soil biodiversity and requires efficient methods to assess the effectiveness of agronomic planning. Knowledge of the landscape and relative pedosite is enriched by data on the soil microarthropod community, which represent useful bio-indicators for early soil-quality detection in land-use change (LUC). In the hilly Maremma region of Grosseto, Italy, two areas, a >10ys meadow converted into a vineyard and an old biodynamic vineyard (no-LUC), were selected for evaluating the LUC effect. For maintaining soil vitality and ecosystem services by meadow, the vineyard was planted and cultivated using criteria of the patented “Corino method”. The aim was to evaluate the LUC impact, within one year, by assessing parameters characterizing soil properties and soil microarthropod communities after the vineyard was planted. The adopted preservative method in the new vineyards did not show a detrimental impact on the biodiversity of soil microarthropods, and in particular, additional mulching contributed to a quick recovery from soil stress due to working the plantation. In the short term, the adopted agricultural context confirmed that the targeted objectives preserved the soil quality and functionality.


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