Topsoil

Technical soil classifications are generated with specific purposes and practical objectives. For the application of these systems, it is necessary to have a soil map, because each mapping unit is classified and those that are similar are regrouped. Mexico has soil maps at 1:50 000 scales, made by the National Institute of Statistics, Geography and Informatics (INEGI), that can be used as base map for application of technical soil classifications. However, their quality has been questioned and many people prefer to use other maps, and moreover, the technical soil classification systems that are used have not been generated in Mexico, and they need evaluation. The objective of this paper was to use the local knowledge of lands as a reference for the application and evaluation of two technical soil classification systems, the Capacity-Fertility classification and Topsoil classification. A map of land classes was made taking into account the farmers knowledge, especially those producin...

M’nasra region is well known for increasing levels of heavy metal pollution in the environment, mainly due to waste discharge of Ouled Berjal, the irrational use of fertilizers, and the discharge of waste from several industries. The objective of this study was to access the seasonal variations in the groundwater and soil quality with respect to heavy metal pollution. Water samples from wells and samples from soil near them were taken during wet (January - March 2017) and dry (July 2017) seasons and concentrations of Cd, Cu, Cr, Mn, Ni, Pb, and Zn were determined using an Atomic Absorption Spectrophotometer (AAS). Contamination factor for each heavy metal and Nemerow pollution index was calculated. Results of the study revealed a decrease in pollution degree from wet to dry for soil and an increase in the case of groundwater. Cu had the lowest and Ni had the highest concentration in irrigation water whereas, for soil, Cd had the lowest and Zn had the highest concentration. During th...

ABSTRACT Farmers’ perceptions of earthworms were surveyed based on the criteria they use to identify them, i.e., use of common names, knowledge of morphological characteristics, presence in various land uses, soil layers, as well as direct and indirect use. A total of 39 farmers of the La Vieja River watershed in Colombia were interviewed and the data submitted to chi-square test and multiple correspondence analysis. Significant differences (p < 0.1) were found in farmers’ replies in relation to recognition and use of earthworms depending on gender, level of schooling, and age. According to the interviewees, earthworm abundance was highest in plantain and coffee crops, in places where harvest residues accumulate, and in soil layers from 0 to 20 cm depth. The topsoil was identified as the main area of recognition, which can be attributed to soil preparation tasks. Farmers differentiated earthworms by shape and color and in 97% of the cases, by size and how they react when captured. They recognized nine species and used several common names to differentiate them. Most (95%) farmers considered earthworms as soil quality indicators and many (38–49%) of them recognized their use for recreation and medicinal purposes and as important for soil organic matter decomposition. This study showed the value of local farmer knowledge for scientists as part of research aiming to facilitate communication between farmers and scientists and generate complementary means of addressing and interpreting natural processes and dynamics at the ecosystem level. It also highlights the need to draw from farmers’ perceptions in informal education processes and to link the contributions of scientists to traditional knowledge in order to consolidate proposals related to biodiversity conservation and use in rural development programs.

The medium- to long-term impacts of forest restoration models on soil properties are not well documented in the Atlantic Forest biome, especially in a seasonally dry climate. We assessed patterns of topsoil fertility, soil organic carbon (SOC) storage, and isotopic signatures of 13C in gradient with three areas with natural regeneration of native forest (NF) with 50 years of old, two areas with monocultures of N2-fixer and non-N2-fixer tree species, six years after planting on grass pasture, and one area with grass pasture in the last 40 years of age. In each area, three to nine composite soil samples were collected at 0-20 cm soil depth during the rainy season for analysis. The topsoil of the NF regenerated after coffee was the most depleted soil fertility and SOC storage in our vegetation gradient. The grass pasture and forest plantations showed smaller soil acidity and a larger base concentrations than the NF areas. The SOC storage was larger in NF after grass pasture and selecti...

Spatial analysis and fuzzy classification techniques were used to estimate the spatial distributions of heavy metals in soil. The work was applied to soils in a coastal region that is characterized by intense urban occupation and large numbers of different industries. Concentrations of heavy metals were determined using geostatistical techniques and classes of risk were defined using fuzzy classification. The resulting prediction mappings identify the locations of high concentrations of Pb, Zn, Ni, and Cu in topsoils of the study area. The maps show that areas of high pollution of Ni and Cu are located at the northeast, where there is a predominance of industrial and agricultural activities; Pb and Zn also occur in high concentrations in the northeast, but the maps also show significant concentrations of Pb and Zn in other areas, mainly in the central and southeastern parts, where there are urban leisure activities and trade centers. Maps were also prepared showing levels of pollution risk. These maps show that (1) Cu presents a large pollution risk in the north–northwest, midwest, and southeast sectors, (2) Pb represents a moderate risk in most areas, (3) Zn generally exhibits low risk, and (4) Ni represents either low risk or no risk in the studied area. This study shows that combining geostatistics with fuzzy theory can provide results that offer insight into risk assessment for environmental pollution.

1. The view of post-mining sites is rapidly changing among ecologists and conservationists, as sensitive restoration using spontaneous succession may turn such sites into biodiversity refuges in human-exploited regions. However, technical reclamation, consisting of covering the sites by topsoil, sowing fast-growing herb mixtures and planting trees, is still commonly adopted. Until now, no multi-taxa study has compared technically reclaimed sites and sites left with spontaneous succession.2. We sampled communities of vascular plants and 10 arthropod groups in technically reclaimed and spontaneously restored plots in limestone quarries in the Bohemian Karst, Czech Republic. For comparison, we used paired t-tests and multivariate methods, emphasizing red-list status and habitat specialization of individual species.3. We recorded 692 species of target taxa, with a high proportion of red-listed (10%) and xeric specialist (14%) species, corroborating the great conservation potential of the quarries.4. Spontaneously restored post-mining sites did not differ in species richness from the technical reclaimed sites but they supported more rare species. The microhabitat cover of leaf litter, herbs and moss, were all directly influenced by the addition of topsoil during reclamation.5.Synthesis and applications. Our results show that the high conservation potential of limestone quarries could be realized by allowing succession to progress spontaneously with minimal intervention. Given the threat to semi-natural sparsely vegetated habitats in many regions, active restoration measures at post-mining sites should be limited to maintenance of early successional stages, instead of acceleration of succession.

This paper derives the distribution of peatland in Europe as the extent of peat and peat-topped soils indicated by soil databases. The data sources were the 1:1,000,000 European Soil Database (v1.0) and a data set of organic carbon content (%) for the topsoils of Europe at 1km x ...

In a field experiment 60kgNha−1 of 15N-labelled fertilizer was applied to Miscanthus×giganteus planted 1, 2 or 3 years previously. Plots were destructively sampled at senescence 1, 2 or 3 years after labelled N was applied with aerial biomass harvested in intervening years. The objective was to quantify N uptake and distribution within the plant, labelled N remaining in the soil