Geospatial assessment of wetland soils for rice production in Ajibode using geospatial techniques

Wetlands played an important role in human development and nature nutrient store for rice cultivation. Spatial techniques have gained importance in monitoring wetland changes. The study aimed to assess wetland soils for rice production using spatial techniques. The area was sample using stratified grid sampling. Nutrient availability and rice suitability were assessed in ArcGIS 10.6 environment. The soil was characterized into Eutric fluvaquent (Soil Survey Staff, 2010) and correlated as fluvisols in the World Reference Base system. The results of the land cover changes showed that built-up, waterbody, and farmland have increased by 39, 18, and 29%, respectively, and 13% decrease was observed in vegetation. The study concluded that soils of the studied area varied from marginally (75%), not suitable (20%), and permanently not suitable (5%) for rice production. Therefore, without proper assessment and management of these studied soils, rice production will continue to be futile.

Aeolian sands and soils of a Wetland Biosphere Reserve: The Tablas de Daimiel

Three soil profiles were characterized from a sandy area situated in a transitional zone in the “Tablas de Daimiel” UNESCO wetland biosphere reserve (TDNP) in the Mancha Plain (Central Spain). The original thickness of the soil layer in this area was as much as 100 cm, but the combined effect of unbalanced cultivation (including irrigation) and an increasingly dry climate has partially eroded their natural properties, almost leading to a desertification process. The main properties of these soils, classified as Xeropsamments (Soil Survey Staff 2006) or Arenosols (IUSS Working Group WRB 2006), are the dominance of sand in the soil matrix, its basic character, and low soil organic matter and carbonate contents. Scanning electron microscopy of the quartz grain surfaces indicated that the superficial textureswere commonly well preserved and characteristic of specific conditions of aeolian formation. Exoscopy revealed a mixture of sub-angular and rounded quartz morphotypes withwell-preserved mechanical impacts on the grain surfaces. These percussion effects are characteristic of aeolian processes and confirmed that mechanical actions were more significant than chemical processes in their pedogenesis.This micromorphological study of the textural sands in the transitional zone of the TDNP revealed that the (red) sands were transported to this area by wind, probably from material of degraded red soils, and deposited on soil horizons previously developed over marls and limestones. The relict character of these materials and specially their susceptibility to degradation should be considered as a priority argument to preserve this area and introduce management measurements to avoid soil erosion.

PEASANT AND SCIENTIFIC KNOWLEDGE ON PLANOSOLS AS A SOURCE OF MATERIALS IN THE MAKING OF NON-INDUSTRIAL POTTERY

Ethnopedological studies have mainly focused on agricultural land uses and associated practices. Nevertheless, peasant and indigenous populations use soil and land resources for a number of additional purposes, including pottery. In the present study, we describe and analyze folk knowledge related to the use of soils in non-industrial pottery making by peasant potters, in the municipality of Altinho, Pernambuco State, semiarid region at Brazil. Ethnoscientific techniques were used to record local knowledge, with an emphasis on describing the soil materials recognized by the potters, the properties they used to identify those soil materials, and the criteria employed by them to differentiate and relate such materials. The potters recognized three categories of soil materials: “terra” (earth), “barro” (clay) and, “piçarro” (soft rock). The multi-layered arrangement of these materials within the soil profiles was similar to the arrangement of the soil horizon described by formal pedologists. “Barro vermelho” (red clay) was considered by potters as the principal ceramic resource. The potters followed morphological and utilitarian criteria in distinguishing the different soil materials. Soils from all of these sites were sodium-affected Alfisols and correspond to Typic Albaqualf and Typic Natraqualf in the Soil Taxonomy (Soil Survey Staff, 2010).

Estudio de algunos procesos pedogenéticos en el valle de Ojos Negros, Baja California, México

El estudio sistemático de suelos en Baja California, México, ha sido pobremente desarrollado. Solamente se han encontrado algunos reportes en la literatura científica, realizados en el Desierto Central. El objetivo de este trabajo es estudiar los procesos pedogenéticos que han permitido el desarrollo de los suelos en el valle de Ojos Negros, Baja California, bajo un ambiente mediterráneo. Para el estudio se utilizó el método jerárquico propuesto por Zinck (1988). Se estableció un ambiente morfogenético de naturaleza deposicional que permitió separar cuatro paisajes; lomeríos piedemonte, planicie de nivel de base y valle fluvial, los que fueron subdivididos por relieve/modelado y por características litológicas y sus correspondientes unidades de suelos a nivel de Gran Grupo de acuerdo con el Soil Survey Staff (1992).Estos suelos se formaron bajo diferentes ambientes, materiales, condiciones climáticas, con periodos glaciares e interglaciares de sequía y humedad. Estos procesos se iniciaron desde el Plioceno y continúan en la actualidad, manifestándose en su pedogénesis. Algunos han desarrollado horizontes Bt rojos sobre esquistos y gneiss, (Rhodoxeralfs), otros desarrollados sobre detritos graníticos, presentan un pobre desarrollo (Xeropsamments); materiales graníticos con procesos coluvio-aluvial han formado suelos poligenéticos, horizontes C, con la presencia de horizontes Bt rojos (4CBt), arcilla heredada y hierro amorfo (Haploxeralfs). Algunos otros manifiestan influencia gley (Cegz1, Gley1 6/5GY, Fluvaquents).Los procesos de erosión, transporte y acumulación de materiales en las tierras bajas continúan a la fecha, asimismo, la presencia de un proceso relativamente reciente: materiales que están siendo redistribuidos por el viento y depositados sobre diques de metarriolita, provocado por las condiciones de sequía en toda la región.

Levantamiento de suelos del Municipio de Tuxpan Nayarit, México

Se realizó un levantamiento de suelos semidetallado utilizando la metodología propuesta en 1974 por Elbersen et al., actualizada en 1986 por Villota y Forero y en 1993 por el Soil Survey Staff, mediante el análisis fisiográfico y fotointerpretación se delinearon las unidades de mapeo, mismas que fueron apoyadas con el conocimiento tradicional de los campesinos, la descripción de suelos se baso en Cuanalo (1990). Se describieron 35 perfiles, con un total de 140 muestras a las que se les practicó análisis físicos y químicos para clasificarlos taxonómicamente. Se determinó la disponibilidad de nutrimentos y se sugieren practicas generales de manejo para cada unidad de mapeo.

Diferenciação e distribuição de solos, em diversos níveis categóricos, de duas áreas aparentemente homogêneas de oxissolo

Em duas áreas de oxissolo aparentemente homogêneas, com 18,5 ha (Estação Experimental de Limeira) e 16,5 ha (Estação Experimental de Ribeirão Preto) de superfície foi demarcada uma rede de prospecção com 50 metros de malha. Fez-se a descrição morfológica e foram coletados materiais das camadas 0 - 30 e 80 - 120 m em 74 pontos da área e em 66 da área-2. Uma série de análises foi efetuada a fim de se poder classificar o solo correspondente a cada ponto segundo a classificação elaborada pelo Soil Survey Staff, cartografar as áreas em vários níveis categóricos e verificar a homogeneidade das áreas, do ponto de vista taxonômico. Observou-se que, tanto em superfície como em profundidade, os solos apresentaram, nas duas áreas, pequena variação nas características morfológicas, não tendo se destacado, com exceção da textura, do contato petroférrico e da espessura verificados na área-2, nenhuma característica como diferenciadora de classe. Apenas com observações morfológicas é impraticável chegar-se ao nível de grande grupo, visto que a diferenciação dessa categoria na ordem Oxissolo fica na dependência da caracterização analítica do material e não foi possível, nas áreas de estudo, relacionar a morfologia com os dados analíticos. Podem-se considerar as categorias de família na area-1 e de subgrupo na área-2, como as mais adequadas ao nível de levantamento semidetalhado e na escala de publicação de 1:50.000.