scholarly journals Spatial variability of soil properties and soil erodibility in the Alqueva dam watershed, Portugal

2015 ◽  
Vol 7 (1) ◽  
pp. 301-327 ◽  
Author(s):  
V. Ferreira ◽  
T. Panagopoulos ◽  
R. Andrade ◽  
C. Guerrero ◽  
L. Loures
Keyword(s):  
Land Use ◽  
Spatial Variability ◽  
Soil Properties ◽  
Management Practices ◽  
Fine Sand ◽  
Multivariate Techniques ◽  
Soil Erodibility ◽  
Land Uses ◽  
Local Soil ◽  
K Factor

Abstract. The aim of this work is to investigate how the spatial variability of soil properties and soil erodibility (K factor) were affected by the changes in land use allowed by irrigation with water from a reservoir in a semiarid area. To this, three areas representative of different land uses (agroforestry grassland, Lucerne crop and olive orchard) were studied within a 900 ha farm. The interrelationships between variables were analyzed by multivariate techniques and extrapolated using geostatistics. The results confirmed differences between land uses for all properties analyzed, which was explained mainly by the existence of diverse management practices (tillage, fertilization and irrigation), vegetation cover and local soil characteristics. Soil organic matter, clay and nitrogen content decreased significantly, while K factor increased with intensive cultivation. The HJ-biplot methodology was used to represent the variation of soil erodibility properties grouped in land uses. Native grassland was the least correlated with the other land uses. K factor demonstrated high correlation mainly with very fine sand and silt. The maps produced with geostatistics were crucial to understand the current spatial variability in the Alqueva region. Facing the intensification of land-use conversion, a sustainable management is needed to introduce protective measures to control soil erosion.

scholarly journals Spatial variability of soil properties and soil erodibility in the Alqueva reservoir watershed

Solid Earth ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 383-392 ◽  
Author(s):  
V. Ferreira ◽  
T. Panagopoulos ◽  
R. Andrade ◽  
C. Guerrero ◽  
L. Loures
Keyword(s):  
Land Use ◽  
Spatial Variability ◽  
Soil Properties ◽  
Management Practices ◽  
Fine Sand ◽  
Multivariate Techniques ◽  
Soil Erodibility ◽  
Land Uses ◽  
Local Soil ◽  
K Factor

Abstract. The aim of this work is to investigate how the spatial variability of soil properties and soil erodibility ($K$ factor) were affected by the changes in land use allowed by irrigation with water from a reservoir in a semiarid area. To this end, three areas representative of different land uses (agroforestry grassland, lucerne crop and olive orchard) were studied within a 900 ha farm. The interrelationships between variables were analyzed by multivariate techniques and extrapolated using geostatistics. The results confirmed differences between land uses for all properties analyzed, which was explained mainly by the existence of diverse management practices (tillage, fertilization and irrigation), vegetation cover and local soil characteristics. Soil organic matter, clay and nitrogen content decreased significantly, while the K factor increased with intensive cultivation. The HJ-Biplot methodology was used to represent the variation of soil erodibility properties grouped in land uses. Native grassland was the least correlated with the other land uses. The K factor demonstrated high correlation mainly with very fine sand and silt. The maps produced with geostatistics were crucial to understand the current spatial variability in the Alqueva region. Facing the intensification of land-use conversion, a sustainable management is needed to introduce protective measures to control soil erosion.

scholarly journals Characteristics of Soil Erodibility K Value and Its Influencing Factors in the Changyan Watershed, Southwest Hubei, China

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Xiaofang Huang ◽  
Lirong Lin ◽  
Shuwen Ding ◽  
Zhengchao Tian ◽  
Xinyuan Zhu ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Spatial Variability ◽  
Influencing Factors ◽  
Soil Type ◽  
Soil Survey ◽  
Purple Soil ◽  
Soil Erodibility ◽  
K Value ◽  
K Factor

Soil erodibility K factor is an important parameter for evaluating soil erosion vulnerability and is required for soil erosion prediction models. It is also necessary for soil and water conservation management. In this study, we investigated the spatial variability characteristics of soil erodibility K factor in a watershed (Changyan watershed with an area of 8.59 km2) of Enshi, southwest of Hubei, China, and evaluated its influencing factors. The soil K values were determined by the EPIC model using the soil survey data across the watershed. Spatial K value prediction was conducted by regression-kriging using geographic data. We also assessed the effects of soil type, land use, and topography on the K value variations. The results showed that soil erodibility K values varied between 0.039–0.052 t·hm2·h/(hm2·MJ·mm) in the watershed with a block-like structure of spatial distribution. The soil erodibility, soil texture, and organic matter content all showed positive spatial autocorrelation. The spatial variability of the K value was related to soil type, land use, and topography. The calcareous soil had the greatest K value on average, followed by the paddy soil, the yellow-brown soil (an alfisol), the purple soil (an inceptisol), and the fluvo-aquic soil (an entisol). The soil K factor showed a negative correlation with the sand content but was positively related to soil silt and clay contents. Forest soils had a greater ability to resist to erosion compared to the cultivated soils. The soil K values increased with increasing slope and showed a decreasing trend with increasing altitude.

scholarly journals SPATIAL VARIABILITY OF SOIL PROPERTIES IN AN AGRARIAN REFORM SETTLEMENT

2015 ◽  
Vol 39 (6) ◽  
pp. 1755-1763 ◽  
Author(s):  
James Ribeiro de Azevedo ◽  
Célia Regina Paes Bueno ◽  
Gener Tadeu Pereira
Keyword(s):  
Land Use ◽  
Particle Size ◽  
Spatial Variability ◽  
Soil Properties ◽  
Land Use Planning ◽  
Management Practices ◽  
Deciduous Forest ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Environmental Preservation

ABSTRACT The study of soil chemical and physical properties variability is important for suitable management practices. The aim of this study was to evaluate the spatial variability of soil properties in the Malhada do Meio settlement to subsidize soil use planning. The settlement is located in Chapadinha, MA, Brazil, and has an area of 630.86 ha. The vegetation is seasonal submontane deciduous forest and steppe savanna. The geology is formed of sandstones and siltstones of theItapecuru Formation and by colluvial and alluvial deposits. The relief consists of hills with rounded and flat tops with an average altitude of 67 m, and frequently covered over by ferruginous duricrusts. A total of 183 georeferenced soil samples were collected at the depth of 0.00-0.20 m inPlintossolos, Neossolo andGleissolo. The following chemical variables were analyzed: pH(CaCl2), H+Al, Al, SB, V, CEC, P, K, OM, Ca, Mg, SiO2, Al2O3, and Fe2O3; along with particle size variables: clay, silt, and sand. Descriptive statistical and geostatistical analyses were carried out. The coefficient of variation (CV) was high for most of the variables, with the exception of pH with a low CV, and of sand with a medium CV. The models fitted to the experimental semivariograms of these variables were the exponential and the spherical. The range values were from 999 m to 3,690 m. For the variables pH(CaCl2), SB, and clay, there are three specific areas for land use planning. The central part of the area (zone III), where thePlintossolos Pétricos and Neossolos Flúvicos occur, is the most suitable for crops due to higher macronutrient content, organic matter and pH. Zones I and II are indicated for environmental preservation.

scholarly journals Effects of soil depth on the dynamics of selected soil properties among the highlands resources of Northeast Wollega, Ethiopia: are these sign of degradation?

2015 ◽  
Vol 7 (3) ◽  
pp. 2011-2035 ◽  
Author(s):  
A. Adugna ◽  
A. Abegaz
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
Management Practices ◽  
Soil Depth ◽  
Soil Samples ◽  
Land Uses ◽  
Land Use Patterns ◽  
Grazing Land ◽  
Internal Factors ◽  
Use Patterns

Abstract. This study was conducted with an aim to analyze the spatial variability of soil properties with depth under four prominent land use patterns viz., forestland, grazing land, cultivated land and bush land of Northeast Wollega. Soil samples were collected from the land uses at two depths (0–15 and 15–30 cm) in replicates and totally 40 composite soil samples were collected. Statistical analysis revealed significant variation in soil properties with along the selected land uses. Topsoil layer had significantly greater OM, TN, AP, sand, silt, Mg2+, K+ and Mg2+ concentrations than the subsoil layers. However, clay under all land uses and CEC under bush land and grazing land revealed reverse trends. Organic matter and CEC have stronger correlations with most of soil properties in the topsoil than in the subsoil while clay has no significant correlation with selected soil properties except with sand fraction in the sampled depths. Hence, the correlation among the selected soil properties also varies with soil depth. In general, the spatial variability of soil properties indicates that they were strongly affected by external factors (agricultural treatments and soil management practices) and internal factors (soil type and depth).

scholarly journals Regionalized Terrestrial Ecotoxicity Assessment of Copper-Based Fungicides Applied in Viticulture

2018 ◽  
Vol 10 (7) ◽  
pp. 2522 ◽  
Author(s):  
Ivan Viveros Santos ◽  
Cécile Bulle ◽  
Annie Levasseur ◽  
Louise Deschênes
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
Regression Models ◽  
Management Practices ◽  
Metal Speciation ◽  
Agricultural Systems ◽  
Geographical Variability ◽  
Terrestrial Ecotoxicity ◽  
The Impact ◽  
Growing Region

Life cycle assessment has been recognized as an important decision-making tool to improve the environmental performance of agricultural systems. Still, there are certain modelling issues related to the assessment of their impacts. The first is linked to the assessment of the metal terrestrial ecotoxicity impact, for which metal speciation in soil is disregarded. In fact, emissions of metals in agricultural systems contribute significantly to the ecotoxic impact, as do copper-based fungicides applied in viticulture to combat downy mildew. Another issue is linked to the ways in which the intrinsic geographical variability of agriculture resulting from the variation of management practices, soil properties, and climate is addressed. The aim of this study is to assess the spatial variability of the terrestrial ecotoxicity impact of copper-based fungicides applied in European vineyards, accounting for both geographical variability in terms of agricultural practice and copper speciation in soil. This first entails the development of regionalized characterization factors (CFs) for the copper used in viticulture and then the application of these CFs to a regionalized life-cycle inventory that considers different management practices, soil properties, and climates in different regions, namely Languedoc-Roussillon (France), Minho (Portugal), Tuscany (Italy), and Galicia (Spain). There are two modelling alternatives to determine metal speciation in terrestrial ecotoxicity: (a) empirical regression models; and (b) WHAM 6.0, the geochemical speciation model applied according to the soil properties of the Harmonized World Soil Database (HWSD). Both approaches were used to compute and compare regionalized CFs with each other and with current IMPACT 2002+ CF. The CFs were then aggregated at different spatial resolutions—global, Europe, country, and wine-growing region—to assess the uncertainty related to spatial variability at the different scales and applied in the regionalized case study. The global CF computed for copper terrestrial ecotoxicity is around 3.5 orders of magnitude lower than the one from IMPACT 2002+, demonstrating the impact of including metal speciation. For both methods, an increase in the spatial resolution of the CFs translated into a decrease in the spatial variability of the CFs. With the exception of the aggregated CF for Portugal (Minho) at the country level, all the aggregated CFs derived from empirical regression models are greater than the ones derived from the method based on WHAM 6.0 within a range of 0.2 to 1.2 orders of magnitude. Furthermore, CFs calculated with empirical regression models exhibited a greater spatial variability with respect to the CFs derived from WHAM 6.0. The ranking of the impact scores of the analyzed scenarios was mainly determined by the amount of copper applied in each wine-growing region. However, finer spatial resolutions led to an impact score with lower uncertainty.

scholarly journals Wildlife and Land Use in Highland Scotland

Oryx ◽  
1973 ◽  
Vol 12 (1) ◽  
pp. 53-63
Author(s):  
James Lockie
Keyword(s):  
Land Use ◽  
Seventeenth Century ◽  
Red Deer ◽  
Management Practices ◽  
Red Fox ◽  
Land Uses ◽  
Red Grouse ◽  
Scottish Highlands ◽  
Wildlife Species ◽  
Intense Exploitation

Depopulation of the Scottish Highlands in the seventeenth century was followed by intense exploitation and often misuse of the land, with serious overgrazing, burning and wildlife destruction. Today the main land uses are hill sheep farming, crofting, sport, and, more recently, commercial timber growing, nature conservation, hydroelectric schemes and tourism. The author, who is on the staff of the Department of Forestry and Natural Resources in Edinburgh University, examines the effect of these activities on four main wildlife species – golden eagle, red deer, red grouse and red fox – and describes some of the mistaken management practices which damage the wildlife, often without producing the desired results.

Spatial variability of the physical-hydric properties of cohesive soils under rainfed and irrigated sugarcane cultivations

2021 ◽  
Author(s):  
Brivaldo Gomes de Almeida ◽  
Bruno Campos Mantovanelli ◽  
Thiago Rodrigo Schossler ◽  
Fernando José Freire ◽  
Edivan Rodrigues de Souza ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Variability ◽  
Structural Changes ◽  
Management Practices ◽  
Geometric Mean ◽  
Soil Layer ◽  
Multivariate Techniques ◽  
Geostatistical Approach ◽  
Physical Attributes ◽  
Soil Spatial Variability

<p>Geostatistical and multivariate techniques have been widely used to identify and characterize the soil spatial variability, as well as to detect possible relationships between soil properties and management. Besides that, these techniques provide information regarding the spatial and temporal structural changes of soils to support better decision-making processes and management practices. Although the Zona da Mata region is a reference for sugarcane production in the northeast of Brazil, only a few studies have been carried out to clarify the effects of different management on soil physical attributes by using geostatistical and multivariate techniques. Thus, the objectives of this study were: (I) to characterize the spatial distribution of soils physical attributes under rainfed and irrigated sugarcane cultivations; (II) to identify the minimum sampling for the determination of soil physical attributes; (III) to detect the effects of the different management on soil physical attributes based on the principal component analysis (PCA). The study was carried out in the agricultural area of the Carpina Sugarcane Experimental Station of the Federal Rural University of Pernambuco, 7º51’13”S, 35º14’10”W, characterized by a Typic Hapludult with sandy clay loam soil texture. The investigated plot, cultivated with sugarcane, included a rainfed and an irrigated treatment in which a sprinkler system was installed according to a 12x12m grid. The interval between consecutive watering was fixed in two days, whereas irrigation depth was calculated to replace crop evapotranspiration (ETc) and accounting for the effective precipitation of the period. Daily ETc was estimated based on crop coefficient and reference evapotranspiration (ETo) indirectly obtained through a class A evaporation pan. In both treatments, the soil spatial variability was determined according to a 56x32m grid, on 32 soil samples collected in the 0.0-0.1m soil layer, spaced 7x8m, and georeferenced with a global position system. The soil was physically characterized according to the following attributes: bulk density (BD), soil penetration resistance (SPR), macroporosity (Macro), mesoporosity (Meso), microporosity (Micro), total porosity (TP), saturated hydraulic conductivity (Ksat), gravimetric soil water content (SWCg), geometric mean diameter (GMD) and mean weight diameter (MWD). The results of the descriptive statistics showed that among the studied attributes, Ksat, SPR, and Macro presented higher CV values, equal to 63 and 69%, 35 and 40%, and 32 and 44%, under rainfed and irrigated conditions, respectively. The minimum sampling, adequate to characterize the different soil attributes, resulted in general smaller in the rainfed area, characterized by higher homogeneity. Thus, the GMD, SWCg (both with 2 points ha<sup>-1</sup>), and SPR (with 6 points ha<sup>-1</sup>) were identified as the soil physical attributes requiring the lowest sample density; on the other hand, MWD and Ksat, with 14 and 15 points ha<sup>-1</sup>, respectively, required the highest number of samples. Pearson’s correlation analysis evidenced that soil BD was the most influential physical attribute in the studied areas, with a significant and inverse effect in most of the investigated attributes. The geostatistical approach associated with the multivariate PCA provided to understand the relationships between the spatial distribution patterns associated with irrigated and rainfed management and soil physical properties.</p>

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