Comparison of water-stable aggregates on different soil types and land-uses in a Portuguese Mediterranean catchment

2021 ◽  
Author(s):  
Radek Klíč ◽  
Carla Sofia Santos Ferreira ◽  
António Ferreira ◽  
Miroslav Kravka
Keyword(s):  
Forest Soils ◽  
Agricultural Soils ◽  
Soil Aggregates ◽  
Soil Surface ◽  
Soil Types ◽  
Land Uses ◽  
Water Stable Aggregates ◽  
Erosion Processes ◽  
Long Time ◽  
Central Portugal

<p>Erosion is one of the main soil threats in the Mediterranean region, leading to degradation and desertification of several areas. Water stable aggregates (WSA) is a rate of the extent to which soil aggregates resist falling apart when wetted and hit by rain drops, indicating also the resistence of soil to compaction and soil quality status. This study aims to determine the WSA in differrent soils, characterized by distinct land-uses and soil types. This work is part of Ribeira dos Covões catchment research, in the suburbs of Coimbra, the largest city of central Portugal, where research dealing with soil and hydrological properties has been developed for long time. WSA were investigated for agricultural and forest soils, on both sandstone and limestone. Soil surface samples (0-10cm) were collected in December 2020, and analysed through wet sieving method which quantifies the amount of water-stable soil aggregates fractions. <br><br>Not surprisingly, the results showed that forest soils contain a much higher proportion of water-stable soil aggregates of larger fractions than agricultural soil, where the smaller fractions prevailed. Similar results have been also reported in previous studies and found during our previous research at Praha-Suchdol locality (Housle), in Czech Republic. The fraction distribution of WSA in sandstone and limestone was comparable for forest soils. In case of agricultural soils, distribution of WSA was slightly different. WSA are a relevant part of soil surface layer, with important impacts on other soil properties (e.g. soil moisture, hydrophobicity, infiltration), thus affecting the rainfall-runoff-erosion processes, previously investigated in the study area. Further research will be developed to better assess WSA differences between distinct forest types, given the relevance of vegetation species for example on hydrophobicity and WSA dynamics. A better understanding of WSA in different soil types will be useful to support improved soil management and mitigate land degradation.</p>

A multi-decade assessment of the impact of large fire events on sediment redistribution using LAPSUS - the Águeda catchment, north-central Portugal

2021 ◽  
Author(s):  
Dante Föllmi ◽  
Jantiene Baartman ◽  
João Pedro Nunes ◽  
Akli Benali
Keyword(s):  
Soil Depth ◽  
Spatial Scales ◽  
Fire Severity ◽  
Sediment Dynamics ◽  
Land Uses ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Sediment Redistribution ◽  
Central Portugal ◽  
The Impact

<p><strong>Abstract</strong></p><p>Wildfires have become an increasing threat for Mediterranean ecosystems, due to increasing climate change induced wildfire activity and changing land management practices. Apart from the initial risk, fire can alter the soil in various ways depending on different fire severities and thus post-fire erosion processes are an important component in assessing wildfires’ negative effects. Recent post-fire erosion (modelling) studies often focus on a short time window and lack the attention for sediment dynamics at larger spatial scales. Yet, these large spatial and temporal scales are fundamental for a better understanding of catchment sediment dynamics and long-term destructive effects of multiple fires on post-fire erosion processes. In this study the landscape evolution model LAPSUS was used to simulate erosion and deposition in the 404 km<sup>2</sup> Águeda catchment in northern-central Portugal over a 41 year (1979-2020) timespan. To include variation in fire severity and its impact on the soil four burnt severity classes, represented by the difference Normalized Burn Ratio (dNBR), were parameterized. Although model calibration was difficult due to lack of spatial and temporal measured data, the results show that average post-fire net erosion rates were significantly higher in the wildfire scenarios (5.95 ton ha<sup>-1</sup> yr<sup>-1</sup>) compared to those of a non-wildfire scenario (0.58 ton ha<sup>-1</sup> yr<sup>-1</sup>). Furthermore, erosion values increased with a higher level of burnt severity and multiple fires increased the overall sediment build-up in the catchment, fostering an increase in background sediment yield. Simulated erosion patterns showed great spatial variability with large deposition and erosion rates inside streams. Due to this variability, it was difficult to identify land uses that were most sensitive for post-fire erosion, because some land-uses were located in more erosion-sensitive areas (e.g. streams, gullies) or were more affected by high burnt severity levels than others. Despite these limitations, LAPSUS performed well on addressing spatial sediment processes and has the ability to contribute to pre-fire management strategies. For instance, the percentage soil loss map (i.e. comparison of erosion and soil depth maps) could identify locations at risk.</p>

LES EFFETS DE LA MISE EN CULTURE ET DE LA PRAIRIE PROLONGEE SUR LE CARBONE, L'AZOTE ET LA STRUCTURE DE QUELQUES SOLS DU QUEBEC

1976 ◽  
Vol 56 (4) ◽  
pp. 373-383 ◽  
Author(s):  
Y. A. MARTEL ◽  
J. M. DESCHENES
Keyword(s):  
Carbon Content ◽  
Root Biomass ◽  
Soil Structure ◽  
Agricultural Soils ◽  
Soil Aggregates ◽  
Cultural Practice ◽  
Water Stability ◽  
Virgin Soil ◽  
Soil Series ◽  
Water Stable Aggregates

The effects of cultivation (cultivated vs. non-cultivated soils) and the age of cultivated meadows (from 5 to 25 yr) on the evolution of carbon, nitrogen and soil structure were studied on some Quebec soils. The soil series used were Beaurivage, Charlevoix, Greensboro and Kamouraska which are important agricultural soils for Eastern Quebec. The air- and water-stability of soil aggregates were used to characterize the soil structure. As a result of cultivation, the Kamouraska soil lost 33% of the carbon and 8% of the nitrogen originally present in the virgin soil, while the decrease in the water-stable aggregates was 84%. Charlevoix and Greensboro soils showed losses varying from 30 to 35% for carbon and from 21 to 31% for nitrogen while the water-stable aggregates decreased by 50%. Under continuous meadow for 25 yr, the Kamouraska soil showed an increase of up to 36% for carbon and 64% for nitrogen whereas the Beaurivage soil did not show much variation. Such a cultural practice improved the soil structure mainly in the Kamouraska soil, as a result of the increase not only in carbon content but likely in the root biomass with time.

scholarly journals Polyester Microplastic Fibers affect Soil Physical Properties and Erosion as a Function of Soil Type

2021 ◽  
Author(s):  
Rosolino Ingraffia ◽  
Gaetano Amato ◽  
Vincenzo Bagarello ◽  
Francesco G. Carollo ◽  
Dario Giambalvo ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Soil Properties ◽  
Soil Type ◽  
Agricultural Soils ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Physical Parameters ◽  
Organic Carbon Content ◽  
Erosion Processes ◽  
Environmental Compartments

Abstract. Microplastic is recognized as a factor of global change affecting many environmental compartments. Agricultural soils are likely hotspots of microplastic contamination in terrestrial ecosystems and are of particular concern due to their role in food production. Microplastic has already been shown to be able to affect soil properties, but its effect on different soil types is poorly understood. Moreover, no information is available on how the presence of this pollutant can affect soil water erosion processes, which are extremely important issues in many environments. In the light of this, we performed two experiments (a microcosm and a mesocosm study) to investigate how the presence of polyester microplastic fibers affects soil physical and hydrological parameters and processes such as aggregate formation and soil erosion in three different agricultural soil types. Our data show that the effects of polyester microplastic on soil physical parameters (including soil aggregation and erosion) are strongly dependent on soil type. We found that microplastic contamination can decrease the formation of new aggregates but at the same time increase their stability in water, with effects on soil erosion stronger as the intrinsic erodibility of soil increases. Overall, our results highlight the importance of broadly exploring soil properties such as texture, mineralogy, and organic carbon content to better understand how the various soil types respond to microplastic contamination.

scholarly journals Retention of the Antibiotic Cefuroxime onto Agricultural and Forest Soils

2021 ◽  
Vol 11 (10) ◽  
pp. 4663
Author(s):  
Raquel Cela-Dablanca ◽  
Carolina Nebot ◽  
Lucia Rodríguez López ◽  
David Ferández-Calviño ◽  
Manuel Arias-Estévez ◽  
...  
Keyword(s):  
Forest Soils ◽  
Linear Models ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Matter Content ◽  
Batch Type ◽  
Exchangeable Ca ◽  
Influence Of Ph ◽  
Best Fit ◽  
Soil Colloids

Antibiotics in wastewater, sewage sludge, manures, and slurries constitute a risk for the environment when spread on soils. This work studies the adsorption and desorption of the antibiotic cefuroxime (CFX) in 23 agricultural and forest soils, using batch-type experiments. Our results show that the adsorption values were between 40.75 and 99.57% in the agricultural soils, while the range was lower (from 74.57 to 93.46%) in forest soils. Among the Freundlich, Langmuir, and Linear models, the Freundlich equation shows the best fit for the adsorption results. In addition, agricultural soils with higher pH are the ones that present the highest adsorption. Further confirmation of the influence of pH on adsorption is given by the fact that Freundlich’s KF parameter and the Linear model Kd parameter shows a positive correlation with pH and with the exchangeable Ca and Mg values, which are known to affect the charges of the soil colloids and the formation of cationic bridges between adsorbents and adsorbate. In addition, Freundlich’s n parameter shows a positive and significant correlation with the organic matter content, related to the high adsorption taking place on forest soils despite their pH < 5. Regarding desorption, in most cases, it is lower than 1%, which indicates that CFX is adsorbed in a rather irreversible way onto these soils. Overall, these results can be considered relevant regarding their potential impact on environmental quality and public health.

scholarly journals Estimation of Soil Surface Roughness Using Stereo Vision Approach

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4386
Author(s):  
Afshin Azizi ◽  
Yousef Abbaspour-Gilandeh ◽  
Tarahom Mesri-Gundoshmian ◽  
Aitazaz A. Farooque ◽  
Hassan Afzaal
Keyword(s):  
Surface Roughness ◽  
Stereo Vision ◽  
Agricultural Soils ◽  
Depth Map ◽  
Soil Surface ◽  
Regression Equations ◽  
Height Profile ◽  
Peak Fitting ◽  
Soil Surface Roughness ◽  
Tillage Operations

Soil roughness is one of the most challenging issues in the agricultural domain and plays a crucial role in soil quality. The objective of this research was to develop a computerized method based on stereo vision technique to estimate the roughness formed on the agricultural soils. Additionally, soil till quality was investigated by analyzing the height of plow layers. An image dataset was provided in the real conditions of the field. For determining the soil surface roughness, the elevation of clods obtained from tillage operations was computed using a depth map. This map was obtained by extracting and matching corresponding keypoints as super pixels of images. Regression equations and coefficients of determination between the measured and estimated values indicate that the proposed method has a strong potential for the estimation of soil shallow roughness as an important physical parameter in tillage operations. In addition, peak fitting of tilled layers was applied to the height profile to evaluate the till quality. The results of this suggest that the peak fitting is an effective method of judging tillage quality in the fields.

Influence of soil tillage and erosion on the dispersion of glyphosate and aminomethylphosphonic acid in agricultural soils

2014 ◽  
Vol 28 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Gorana Rampazzo Todorovic ◽  
Nicola Rampazzo ◽  
Axel Mentler ◽  
Winfried E.H. Blum ◽  
Alexander Eder ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Soil Tillage ◽  
Erosion Risk ◽  
Erosion Processes ◽  
Run Off ◽  
Aminomethylphosphonic Acid ◽  
Severe Erosion ◽  
Structure State ◽  
Key Parameter ◽  
Percolation Water

Abstract Erosion processes can strongly influence the dissipation of glyphosate and aminomethylphosphonic acid applied with Roundup Max® in agricultural soils; in addition, the soil structure state shortly before erosive precipitations fall can be a key parameter for the distribution of glyphosate and its metabolite. Field rain simulation experiments showed that severe erosion processes immediately after application of Roundup Max® can lead to serious unexpected glyphosate loss even in soils with a high presumed adsorption like the Cambisols, if their structure is unfavourable. In one of the no-tillage-plot of the Cambisol, up to 47% of the applied glyphosate amount was dissipated with surface run-off. Moreover, at the Chernozem site with high erosion risk and lower adsorption potential, glyphosate could be found in collected percolation water transported far outside the 2x2 m experimental plots. Traces of glyphosate were found also outside the treated agricultural fields.

Modelling uranium leaching from agricultural soils to groundwater as a criterion for comparison with complementary safety indicators

2006 ◽  
Vol 932 ◽  
Author(s):  
D. Jacques ◽  
J. Šimůnek ◽  
D. Mallants ◽  
M.Th. van Genuchten
Keyword(s):  
Soil Profile ◽  
Reactive Transport ◽  
Transport Model ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Water Flux ◽  
Fertilizer Application ◽  
Mineral Fertilizers ◽  
Deep Soil ◽  
Long Time

ABSTRACTNaturally occurring radionuclides can also end up in soils and groundwater due to human practices, such as application of certain fertilizers in agriculture. Many mineral fertilizers, particularly (super)phosphates, contain small amounts of 238U and 230Th which eventually may be leached from agricultural soils to underlying water resources. Field soils that receive P-fertilizers accumulate U and Th and their daughter nuclides, which eventually may leach to groundwater. Our objective was to numerically assess U migration in soils. Calculations were based on a new reactive transport model, HP1, which accounts for interactions between U and organic matter, phosphate, and carbonate. Solid phase interactions were simulated using a surface complexation module. Furthermore, all geochemical processes were coupled with a model accounting for dynamic changes in the soil water content and the water flux. The capabilities of the code in calculating natural U fluxes to groundwater were illustrated using a semi-synthetic 200-year long time series of climatological data for Belgium. Based on an average fertilizer application, the input of phosphate and uranium in the soil was defined. This paper discusses calculated U distributions in the soil profile as well as calculated U fluxes leached from a 100-cm deep soil profile. The calculated long-term leaching rates originating from fertilization are significantly higher after 200 years than estimated release rates from lowlevel nuclear waste repositories.

Soil Aggregates Stability of Forest Islands and Adjacent Ecosystems in West Africa

2021 ◽  
Vol 9 (2) ◽  
pp. 283
Author(s):  
Amelie Baomalgré Bougma ◽  
Korodjouma Ouattara ◽  
Halidou Compaore ◽  
Hassan Bismarck Nacro ◽  
Caleb Melenya ◽  
...  
Keyword(s):  
Land Use ◽  
West Africa ◽  
Agricultural Soils ◽  
Direct Action ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Mean Annual Precipitation ◽  
Savanna Vegetation ◽  
Study Sites ◽  
Forest Islands

In the more mesic savanna areas of West Africa, many areas of relatively tall and dense vegetation with a species composition more characteristic of forest than savanna are often found around villages areas. These ‘forest islands’ may be the direct action of human activity. To better understand these patches with relatively luxuriant vegetation, our study focused on how they influence soil aggregation in comparison with nearby areas and natural savanna vegetation across a precipitation transect in West Africa for which mean annual precipitation at the study sites ranges from 0.80 to 1.27 m a-1. Soil samples were taken from 0 to 5 cm and 5 to 10 cm depths and aggregate groups with diameters: > 500 μm, 500-250 μm and 250-53 μm (viz. “macroaggregates”, “mesoaggregates” and “microaggregates”) determined using the wet sieving method. The results showed significantly higher proportion of stable meso and macroaggregates in forest islands and natural savanna compared to agricultural soils (p <0.05). On the other hand, although there was no effect of land-use type on microaggregates stability, there was a strong tendency for the microaggregate fraction across all land use types to increase with increasing precipitation. Soil organic carbon and iron oxides contents are the most important factors influencing aggregate stability in West African ecosystems. By increasing soil structural stability, forest islands contribute to soil erosion reduction and the control of land degradation.

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