8.1. Methodology

For the purposes of sampling, the digital cartographic information provided by CORPOCALDAS (Autonomous Regional Corporation of the Department of Caldas), stratified in three altitudinal ranges: high, medium, and low, considered as representative of the study area, was taken as a basis. The type of sampling applied was of a random nature and was carried out using functions of the ArcGis program based on a number of four repetitions of each combination of the variables "coverage" and "altitudinal range," resulting in a total of 52 sampling points (52 pits, duly georeferenced). The resulting systems are shown in Table 1. The soil samples were made by opening pits of 1 1 1.50 m and making samples in each of them by soil profile (2–4 samples per profile according to horizons and profile morphology), which were processed for analysis in terms of physical and chemical variables. By groups of pits according to their altitudinal position and vegetation cover (5 coverings), a format or spreadsheet for the description of soil profiles was prepared (52 profiles) taking into account the methodology of soil surveys described by Cortés and Malagón [3] and the FAO profile description guide [7], both references updated according to the description method of the Geographic Institute Agustín Codazzi (IGAC) [12]. Soil chemical analyses were carried out in the soil laboratory of the Caldas University and the analyses for the physical variables in the soil physics laboratory of the National University of Colombia, Palmira-Valle. Both the chemical and the physical information were processed by correlation analysis for their interpretation and mapping according to their geo-referencing.

Table 1 indicates the edaphic systems under evaluation with their respective coverage and altitude ranges. The information on soil cover are indicative and taken from CORPOCALDAS and verified in the field, were studied, sampled, and analyzed the soils by means of pits as The Humidity of the Volcanic Soils and Their Impact on the Processes of Mass Removal in Colombia http://dx.doi.org/10.5772/intechopen.80399 97


Table 1. List of systems under evaluation (coverage and altitude range).

8. Studies and research

96 Soil Moisture

8.1. Methodology

Chavarriaga (2014) studied and investigated the physical and chemical characterization of soil profiles. Reference: evaluation of causal factors, effects and feasible management alternatives, the problem of erosion and mass removal of soils in the Maltería—Las Margaritas road transect, right slope of the Chinchiná River, via Magdalena "Department of Caldas-Colombia." The investigation was carried out to identify and diagnose the problem of soil erosion processes in the area of influence of the Maltería-Las Margaritas road transect via Magdalena, right slope of the Chinchiná River, to technically evaluate the factors involved and the causal relationships intervening effect on the problem of erosion and mass removal of soils, weighing risks and impacts, investigated about the factors related to the technical nature of the problem of deterioration of the soil resource, and its alternatives for improvement or mitigation, of the general impacts and develop the physical-chemical knowledge of the problem of environmental deterioration of soils in the area of influence of the Maltería-Las Margaritas road transect via Magdalena, Municipality of Manizales; Secularly converted into a factor of great environmental and socioeconomic impacts, aggravated in the winter periods of the area, which lead to problems of large soil losses, landslides, road restrictions, and all kinds of risks, which compromise important

resources of the region, as losses of landscape, biodiversity and human lives.

their interpretation and mapping according to their geo-referencing.

For the purposes of sampling, the digital cartographic information provided by CORPOCALDAS (Autonomous Regional Corporation of the Department of Caldas), stratified in three altitudinal ranges: high, medium, and low, considered as representative of the study area, was taken as a basis. The type of sampling applied was of a random nature and was carried out using functions of the ArcGis program based on a number of four repetitions of each combination of the variables "coverage" and "altitudinal range," resulting in a total of 52 sampling points (52 pits, duly georeferenced). The resulting systems are shown in Table 1. The soil samples were made by opening pits of 1 1 1.50 m and making samples in each of them by soil profile (2–4 samples per profile according to horizons and profile morphology), which were processed for analysis in terms of physical and chemical variables. By groups of pits according to their altitudinal position and vegetation cover (5 coverings), a format or spreadsheet for the description of soil profiles was prepared (52 profiles) taking into account the methodology of soil surveys described by Cortés and Malagón [3] and the FAO profile description guide [7], both references updated according to the description method of the Geographic Institute Agustín Codazzi (IGAC) [12]. Soil chemical analyses were carried out in the soil laboratory of the Caldas University and the analyses for the physical variables in the soil physics laboratory of the National University of Colombia, Palmira-Valle. Both the chemical and the physical information were processed by correlation analysis for

Table 1 indicates the edaphic systems under evaluation with their respective coverage and altitude ranges. The information on soil cover are indicative and taken from CORPOCALDAS and verified in the field, were studied, sampled, and analyzed the soils by means of pits as stipulated by the international guides of description of soil profiles. The altitudinal information was suggested by researchers to facilitate its analysis.

The mosaic illustrates the different systems of coverage and their altitudinal position and allows to observe the little spatial variability of the soils, preserving similarities in their morphology and their genesis or their own genetic homogeneity or inheritance provided by the ancient deposits of pyroclastic volcanic materials. The ancient and recent volcanic events in a certain way have shaped the landscapes themselves where the profiles of exposed and supralying soils are located and studied to the lithological formations or litho-units dominated by igneous rock materials predominantly but with the participation of shales and other metamorphic materials. In general, this is the panorama of strata or horizons evidencing eminently volcanic features whenever an attempt has been made to discover the soil to such depths edaphologically speaking and that have enabled world literature to highlight the particularities of our soils known as volcanic or volcanic ash (volcanic ash soils).

On the other hand, the exposed mosaic allows a visual approach to obtain knowledge of reality in terms of the fragility of these edaphic ecosystems and therefore their immense susceptibility to erosion or mass removal and accompanying their physical attributes estimate in this study how are sandy and frank sandy textures, friable or loose consistencies, slightly plastic and slightly sticky, loose structures or those without structure in lower horizons markedly pyroclastic, not plastic and not sticky and without structure or loose consistency.

In this regard, the Geographical Institute Agustín Codazzi (IGAC) [12], in studies close to this research area concluded that the alternation of materials: ash-lapilli-pumice sands that have originated different horizons, A and C layers, show that a polycyclic development of these soils allow to deduce the different depositions of pyroclastic materials that have suffered degradation and reconstruct the history of their evolution; in effect, once the horizon was formed, it was buried by new materials, repeating in this way the different cycles of contributions of tephra or pyroclastic layers.

Environmental climate: cold and humid.

Surface stoniness: there is none. Rocky outcrops: there is none.

Encharcamientos: there is none.

Natural drainage: good (good).

Effective depth: moderately deep.

Limited by: alternating layers of pyroclasts.

Natural vegetation: secondary vegetation.

Limitations of use: cold weather and slope.

Floods: there is none.

Water level: not found.

Current use: forest.

8.1.2. Profile interpretation

8.1.3. Chemical characteristics

for many plant species.

Average annual rainfall: 1800–2000 mm. Average annual temperature: 8–15C.

The Humidity of the Volcanic Soils and Their Impact on the Processes of Mass Removal in Colombia

http://dx.doi.org/10.5772/intechopen.80399

99

Mass movements: Class: deformations. Type: cow's foot. Frequency: frequent.

Edaphic climate: temperature regime: mesic. Moisture regime: udic.

Diagnostic horizons: Epipedon: umbric. Endopedon: there is none.

Described by: William Chavarriaga Montoya. Date: April 2014 (Table 2).

Diagnostic characteristics: andic properties, mesic temperature regime, and umbric epipedon.

The soils of the Consociación el Cedral formed of volcanic ash are moderately deep, well drained, with moderate structural development. These soils have brownish and yellowish brown A/C genetic horizons respectively and umbric diagnostic horizon with andic properties,

The results of the chemical analyses indicate that they are strongly acidic reaction soils with pH values between 4.7 and 5.3 with restrictions for K and Mg, whose Potencial De Hidrógenos (pH) is extremely low; they have medium to high values of S and high values of matter organic of soil (MO) and N, with MO being responsible for the CIC due to the low presence of clays. They do not contain aluminum contents that represent a toxicity hazard

for which the consideration is reiterated as moderately evolved soils (Tables 3 and 4).

Erosion: Class: pluvial water. Type: furrows. Degree: moderate.

In any case, the presence of melanization, mineralization, humification, and structural development processes on the horizon indicates a pedogenic development slowed not only by the continuous rejuvenation of the materials but also by the very low temperatures.

The soils have originated from volcanic ashes alternating with sands, lapilli, and pumice. In superficial cases, well drained, they present several A horizons of dark colors with good structural development buried by volcanic sands that in turn are covered by lapilli and pumice; this indicates that they have suffered several periods of rejuvenation. In addition, the A horizon meets all the requirements of an umbric epipedon with andic properties, for which reason the soils have been considered as moderately evolved.

The physical-chemical dynamics of these soils is controlled by the presence of allophone, an amorphous material originating from the alteration of volcanic ash, constituted by Si in tetrahedral site, Al in tetrahedral and octahedral sites, and other octahedral ions with high variable load or high capacity of cationic exchange (CEC), 25–50 cmol(+)/kg of soil, anionic retention power (mainly phosphates), high affinity for humus and high porosity; and these allophones establish with it strong bonds that result in the accumulation of organic matter in the soil.

The humus-allophane interaction gives the soil particular properties such as high porosity constituted by many fine pores and medium observed in many cases and high retention of water or moisture at different tensions as a result of the high microporosity and the presence of allophane and organic matter.

The description and interpretation of the external and internal characteristics of one of the 13 modal profiles representative of the different coverages and uses and in accordance with the heights and their symbol are presented below. The methodology used follows the guidelines and procedures for description and interpretation of the 2013 IGAC in its semi-detailed study of Caldas soils.

8.1.1. External features of the SV24262 profile (2400–2600 m above sea level)

Taxonomy: Typic hapludand.

Cartographic unit: Cedral Consociation. Symbol: VS24262.

Geographical location: Department: Caldas. Municipality: Manizales Site: finca: El Cedral.

Geographical coordinates: X: 851051, 2843; Y: 1049817,0675; Height: 2444 m above sea level.

Landscape: mountain. Type of relief: Andean peaks.

Shape of the terrain: slopes, peaks, and troughs.

Lithology: alternating layers of volcanic ash, lapilli, and sands, on granitic lavas.

Environmental climate: cold and humid.

Average annual rainfall: 1800–2000 mm. Average annual temperature: 8–15C.

Edaphic climate: temperature regime: mesic. Moisture regime: udic.

Erosion: Class: pluvial water. Type: furrows. Degree: moderate.

Mass movements: Class: deformations. Type: cow's foot. Frequency: frequent.

Surface stoniness: there is none.

Rocky outcrops: there is none.

Floods: there is none.

soils allow to deduce the different depositions of pyroclastic materials that have suffered degradation and reconstruct the history of their evolution; in effect, once the horizon was formed, it was buried by new materials, repeating in this way the different cycles of contribu-

In any case, the presence of melanization, mineralization, humification, and structural development processes on the horizon indicates a pedogenic development slowed not only by the

The soils have originated from volcanic ashes alternating with sands, lapilli, and pumice. In superficial cases, well drained, they present several A horizons of dark colors with good structural development buried by volcanic sands that in turn are covered by lapilli and pumice; this indicates that they have suffered several periods of rejuvenation. In addition, the A horizon meets all the requirements of an umbric epipedon with andic properties, for which

The physical-chemical dynamics of these soils is controlled by the presence of allophone, an amorphous material originating from the alteration of volcanic ash, constituted by Si in tetrahedral site, Al in tetrahedral and octahedral sites, and other octahedral ions with high variable load or high capacity of cationic exchange (CEC), 25–50 cmol(+)/kg of soil, anionic retention power (mainly phosphates), high affinity for humus and high porosity; and these allophones establish with it strong bonds that result in the accumulation of organic matter in

The humus-allophane interaction gives the soil particular properties such as high porosity constituted by many fine pores and medium observed in many cases and high retention of water or moisture at different tensions as a result of the high microporosity and the presence of

The description and interpretation of the external and internal characteristics of one of the 13 modal profiles representative of the different coverages and uses and in accordance with the heights and their symbol are presented below. The methodology used follows the guidelines and procedures for description and interpretation of the 2013 IGAC in its semi-detailed study

Geographical location: Department: Caldas. Municipality: Manizales Site: finca: El Cedral. Geographical coordinates: X: 851051, 2843; Y: 1049817,0675; Height: 2444 m above sea level.

Lithology: alternating layers of volcanic ash, lapilli, and sands, on granitic lavas.

8.1.1. External features of the SV24262 profile (2400–2600 m above sea level)

Cartographic unit: Cedral Consociation. Symbol: VS24262.

Landscape: mountain. Type of relief: Andean peaks.

Shape of the terrain: slopes, peaks, and troughs.

continuous rejuvenation of the materials but also by the very low temperatures.

reason the soils have been considered as moderately evolved.

tions of tephra or pyroclastic layers.

the soil.

98 Soil Moisture

of Caldas soils.

allophane and organic matter.

Taxonomy: Typic hapludand.

Encharcamientos: there is none.

Water level: not found.

Natural drainage: good (good).

Effective depth: moderately deep.

Limited by: alternating layers of pyroclasts.

Diagnostic horizons: Epipedon: umbric. Endopedon: there is none.

Diagnostic characteristics: andic properties, mesic temperature regime, and umbric epipedon.

Natural vegetation: secondary vegetation.

Current use: forest.

Limitations of use: cold weather and slope.

Described by: William Chavarriaga Montoya. Date: April 2014 (Table 2).
