7 results for group: review


Alkaline Mineral Soil Amendment: A Climate Change ‘Stabilization Wedge’?

Extreme climate change due to heat-trapping gases, especially carbon dioxide, necessitates its mitigation. In this context, the carbon dioxide sequestration technology of enhanced weathering has for years been investigated, with a possible implementation strategy via alkaline mineral soil amendment being more recently proposed. Candidate materials for enhanced weathering include calcium and magnesium silicates, most notably those belonging to the olivine, pyroxene and serpentine groups of minerals, given their reactivity with CO2 and global availability. When these finely crushed silicate rocks are applied to the soil, the alkaline earth metal cations ...

The potential of rock dust nanoparticles to improve seed germination and seedling vigor of native species: A review

Land degradation as a result of unregulated mineral exploration and mining, negatively impacts local communities and vulnerable ecosystems. Phytoremediation is used as a progressive rehabilitation strategy to stabilize tailings sites, reduce soil erosion and immobilize heavy metal contaminants. However, in order to develop successful and sustainable phytoremediation methods, native plants must overcome several abiotic stressors. This review examines publicly available literature to determine the potential of repurposed tailings materials, in the form of rock dust nanoparticles (RDNPs), as a nanopriming agent to improve seed germination and seedling ...

Opportunity for increasing the soil quality of non-arable and depleted soils in South Africa: A review

The improvement of food security strategies on highly degraded soils has become a major challenge for South Africa, as the need to secure food sources for the growing population under harsher climatic conditions. South Africa is one of the many water scarce countries and is label 30th driest country in the world. The ability of a soil to serve as a growth medium for plants is directly influenced by the chemical, physical, and biological parameters but most importantly the fertility of the soil, which is a prominent part of soil quality. Numerous methods exist to enhance and maintain soil quality including the application of fertilizers and the other ...

Fire effects on the persistence of soil organic matter and long-term carbon storage

One paradigm in biogeochemistry is that frequent disturbance tends to deplete carbon (C) in soil organic matter (SOM) by reducing biomass inputs and promoting losses. However, disturbance by fire has challenged this paradigm because soil C responses to frequent and/or intense fires are highly variable, despite observed declines in biomass inputs. Here, we review recent advances to illustrate that fire-driven changes in decomposition, mediated by altered SOM stability, are an important compensatory process offsetting declines in aboveground biomass pools. Fire alters the stability of SOM by affecting both the physicochemical properties of the SOM and ...

Enhancing natural cycles in agro-ecosystems to boost plant carbon capture and soil storage

One of society’s greatest challenges is sequestering vast amounts of carbon to avoid dangerous climate change without driving competition for land and resources. Here we assess the potential of an integrated approach based on enhancement of natural biogeochemical cycles in agro-ecosystems that stimulate carbon capture and storage while increasing resilience and long-term productivity. The method integrates plant photosynthesis in the form of (cover) crops and agroforestry, which drives carbon capture. Belowground plant-carbon is efficiently stored as stable soil organic carbon. Aboveground crop and tree residues are pyrolyzed into biochar, which is ...

Remineralizing soils? The agricultural usage of silicate rock powders: A review

Soil nutrient depletion threatens global food security and has been seriously underestimated for potassium (K) and several micronutrients. This is particularly the case for highly weathered soils in tropical countries, where classical soluble fertilizers are often not affordable or not accessible. One way to replenish macro- and micronutrients are ground silicate rock powders (SRPs). Rock forming silicate minerals contain most nutrients essential for higher plants, yet slow and inconsistent weathering rates have restricted their use in the past. Recent findings, however, challenge past agronomic objections which insufficiently addressed the factor...

Biofortification of crops with seven mineral elements often lacking in human diets – iron, zinc, copper, calcium, magnesium, selenium and iodine

The diets of over two-thirds of the world’s population lack one or more essential mineral elements. This can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentrations and/or bio- availability of mineral elements in produce (biofortification). This article reviews aspects of soil science, plant physiology and genetics underpinning crop biofortification strategies, as well as agronomic and genetic approaches currently taken to biofortify food crops with the mineral elements most commonly lacking in human diets: iron (Fe), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), ...