The importance of soil education to connectivity as a dimension of soil security

The connectivity concept within soil security posits that people need to have a connection to soil in order to properly value it. Showing how soil is important in everyday life can create connections to soil, because people care about things they see as impacting their quality of life. Education can demonstrate these connections and may take place in either formal or informal settings and over a wide range of age groups. Creating an effective educational environment is critical, which involves understanding the specific group being addressed, including their existing knowledge of and interest in soil. Soil scientists increasingly teach to student groups that need to know about soils within their chosen careers but are not necessarily training to be soil specialists. Within this formal setting, education that demonstrates the various functions that soils provide in support of human wellbeing may be important to connectivity because it clearly demonstrates the impact of soils on peoples’ lives. In less formal settings, it will be important to identify concepts that will resonate with the public or stakeholders, such as terroir, soil health, or soil security, and to effectively reach these groups with a message built around these concepts. Social marketing, social media, storytelling, soil apps, and soil games are all approaches that have promise to deliver the desired message, therefore creating connections between people and soil

Soil science education – a multi-national look at current perspectives

Soil knowledge is essential to address modern global challenges. Soil science education began with soil survey and agricultural activities, with a focus on the traditional subdisciplines of soil chemistry, soil physics, pedology, soil mineralogy, and soil biology. Soil education has evolved to address the needs of an increasing variety of fields and increasingly complex issues, as seen through the move to teach soil content in programs such as biological and ecological sciences, environmental science, and geosciences. A wide range of approaches have been used to teach soil topics in the modern classroom, including not only traditional lecture and laboratory techniques but also soil judging, online tools, computer graphics, animations, and game-based learning, mobile apps, industry partners, open-access materials, and flipped classrooms. The modern soil curriculum needs to acknowledge the multifunctionality of soils and provide a suite of conduits that connect its traditional subdisciplines with other cognate areas. One way to accomplish this may be to shift from the traditional subdiscipline-based approach to soil science education to a soil functions approach. Strategies to engage the public include incorporating soil topics into primary and secondary school curricula, engaging the public through museums and citizen science projects, and explaining the significance of soil to humanity. Soil education has many challenges and opportunities in the years ahead

Carbon storage in Ghanaian cocoa ecosystems

Background: The recent inclusion of the cocoa sector as an option for carbon storage necessitates the need to quantify the C stocks in cocoa systems of Ghana. Results: Using farmers’ fields, the carbon (C) stocks in shaded and unshaded cocoa systems selected from the Eastern (ER) and Western (WR) regions of Ghana were measured. Total ecosystem C (biomass C + soil C to 60 cm depth) ranged from 81.8 to 153.9 Mg C/ha. The bulk (~89 %) of the systems’ C stock was stored in the soils. The total C stocks were higher in the WR (137.8 ± 8.6 Mg C/ha) than ER (95.7 ± 8.6 Mg C/ha). Conclusion: Based on the cocoa cultivation area of 1.45 million hectares, the cocoa sector in Ghana potentially could store 118.6–223.2 Gg C in cocoa systems with cocoa systems aged within 30 years regardless of shade management. Thus, the decision to include the cocoa sector in the national carbon accounting emissions budget of Ghana is warranted

Erosion, sedimentation and pedogenesis in a polygenetic oxisol sequence in Minas Gerais, Brazil

The geomorphic evolution of the south-eastern Brazilian landscape is attributed to climatic changes coupled with tectonic activity. Soils developed on the resulting surfaces are mainly deep polygenetic Oxisols. The combination of stable landscapes (with continuously exposed soils) and neo-Cenozoic graben zones (episodically filled with sediments that may have undergone soil formation) offers the possibility to unravel the history of the soils that are found at the present day surface. Soil-sediment sequences in the southern part of the state of Minas Gerais, Brazil were investigated by micromorphology and mineralogy in order to understand the genesis of the soils. Erosion (profile thinning), weathering, biological activity, clay accumulation and iron translocation are the main soil forming processes imprinted in the various pedosedimentary layers. Strong weathering is shown by dissolution of quartz and weathering of ilmenite. Bioturbation is ubiquitous even in older and deeper buried layers. Clay accumulation is observed as illuviation and precipitation features which were micromorphologically differentiated. Accumulation and movement of iron are represented by gley and pseudogley features, related to groundwater and surface-water saturation processes. These features and the layering of sediments and soils play key roles in understanding the evolutionary phases undergone by the soils and sediments. As main soil formation episodes, the graben fillings show two phases of clay formation and illuviation, separated by a phase of ferralitization, interrupted by various episodes of erosion. The whole material was eventually overprinted by a phase of ferralitization and plinthite formation. Apart from water saturation, these processes also appear to have acted on the soils of the stable areas (not affected by tectonic activity), but overprinting and erosion prevents recognition of the separate evolutionary phases

Aggregation, organic matter, and iron oxide morphology in oxisols from Minas Gerais, Brazil

The characteristic strong aggregation observed in Oxisols is usually attributed to the presence of free aluminium or iron compounds. Previous investigation of Oxisols from Minas Gerais, Brazil, suggested that iron oxide minerals do not necessarily play a role in aggregation. Oxisol profiles developed on different parent materials (rock-saprolites and sediments), and with different degrees of polygenesis, were investigated to assess whether the physical makeup, rather than the iron content, determines aggregation. Oxisols were investigated by means of micromorphology and laser diffraction grain-sizing. Grain-size distribution curves were determined after three pre-treatments: shaking with water; removal of organic matter; and removal of organic matter followed by deferration. Micromorphology indicated that soils developed on rock-saprolites have hematite droplets (discrete, red colored, equidimensional concentrations) in the saprolite, whereas droplets are not found in soils on Tertiary sediments. However, secondary iron accumulations related to periodic water saturation are encountered in the soils on sediments and not in the soils on rock-saprolites. Grain-size distribution curves showed that the Oxisols on rock-saprolites do not have strong aggregation because of iron oxides alone. Conversely, aggregation by iron oxides is evident in the Oxisols on sediments. This indicates that remobilization of iron during soil formation is essential for iron forms to play a role in aggregation. These findings suggest that the mode of formation and iron mineralogy affect aggregation

Aggregation, organic matter, and iron oxide morphology in oxisols from Minas Gerais, Brazil

The characteristic strong aggregation observed in Oxisols is usually attributed to the presence of free aluminium or iron compounds. Previous investigation of Oxisols from Minas Gerais, Brazil, suggested that iron oxide minerals do not necessarily play a role in aggregation. Oxisol profiles developed on different parent materials (rock-saprolites and sediments), and with different degrees of polygenesis, were investigated to assess whether the physical makeup, rather than the iron content, determines aggregation. Oxisols were investigated by means of micromorphology and laser diffraction grain-sizing. Grain-size distribution curves were determined after three pre-treatments: shaking with water; removal of organic matter; and removal of organic matter followed by deferration. Micromorphology indicated that soils developed on rock-saprolites have hematite droplets (discrete, red colored, equidimensional concentrations) in the saprolite, whereas droplets are not found in soils on Tertiary sediments. However, secondary iron accumulations related to periodic water saturation are encountered in the soils on sediments and not in the soils on rock-saprolites. Grain-size distribution curves showed that the Oxisols on rock-saprolites do not have strong aggregation because of iron oxides alone. Conversely, aggregation by iron oxides is evident in the Oxisols on sediments. This indicates that remobilization of iron during soil formation is essential for iron forms to play a role in aggregation. These findings suggest that the mode of formation and iron mineralogy affect aggregation