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Rocks for Crops: Agrominerals of sub-Saharan Africa.

A productive and sustainable agricultural system is fundamental to the well being of a nation and a cornerstone of its development. In most of sub-Saharan Africa, more than 50% of the population rely on agriculture for their livelihood, which generally contributes more than 30% of the Gross Domestic Product (GDP). Agriculture is the major source of income, employment, food security and survival for the majority of the population. While agricultural production is steadily increasing in sub-Saharan Africa, the population is growing faster than food production. The result is a net decline in per-capita food production, which contributes to increased food ...

Dust in the Wind

On a blistering June day in West and see what appears to be a blood-red curtain billowing the length of the horizon. When the curtain arrives, daylight disappears, and the land is covered in a dark red, gritty-tasting night. Going inside offers little protection—windblown dust soon penetrates shutters and plaster cracks, leaving a thin red layer everywhere; rooms feel like mine shafts. This is a dust storm in Africa’s arid Sahelian band, the southern fringe of the Sahara Desert from Mauritania to Chad. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1240740/

Evaluation for the Potential Use of Silicate Rocks from Four Volcanoes in Indonesia as Fertilizer and Soil Ameliorant

Silicate rocks, the abundant plant nutrient source in Indonesia, have not been evaluated for use as a fertilizer/and soil ameliorant. This research was aimed to identify (1) mineral and elemental compositions of silicate rocks originated from Galunggung, Kelud, Tambora, and Rinjani Volcanoes and (2) soil properties determining dissolution rate of plant nutrients from the silicate rock fertilizers (SRFs). The rocks were ground with a ball mill for 10 min providing SRFs with medians of particle size of 30 – 50 m. Each SRF was added to 6 soils from West Java, East Java, and Lombok Island at a rate equivalent to 20 t ha-1, incubated for 28 days in a ...

A holistic approach to mitigating pathogenic effects on trees

The conventional ‘disease model’ approach to tree health focuses on identifying and controlling a specific pathogen (or pest) implicated as the causal agent of tree decline. Alternatively there are more holistic approaches in tree health that address a broader suite of processes occurring at the ecosystem level which may be predisposing the trees to infection by disease. Here I describe a holistic methodology that takes into account not only the proximal agents involved in tree decline, but also the age and structure of the forest, the abundance of cryptogams, the fire history, the acidity of the precipitation, the fertility of the soil, and the ...

Efficacy, sustainability and diffusion potential of rock dust for soil remediation in Chontales, Nicaragua

To produce enough food for a growing population, soil remediation is crucial unless more forests are to be cleared to make way for agriculture land. Finely ground rocks have been proposed as a soil amendment for highly weathered soils. In Chontales, Nicaragua most of the forest has been converted to cattle pasture. In fertile soils, crop agriculture is more lucrative per unit of area than cattle grazing, but the low nutrient content of Chontales soils makes it uneconomic. The purpose of the study was to examine whether incorporation of rock dust is a sustainable way to increase the fertility in Chontales and thus can be part of a strategy that ...

Rock’s power to mop up carbon revisited

Last week, a group of geoengineers met in Hamburg to discuss what on the face of it sounds like a very attractive idea: to soak up anthropogenic carbon emissions using only rocks and water. In particular, they want to help to mitigate climate change by crushing rocks and dropping them into the sea or spreading them on land. The meeting was hailed a success, but the idea is still far from fruition.   Reprinted by permission from Macmillan Publishers Ltd: Nature News, Vol 505, pp 464, copyright 2014. For the complete article, please visit: http://www.nature.com/news/rock-s-power-to-mop-up-carbon-revisited-1.14560

Prehistoric agricultural depletion of soil nutrients in Hawai‘i

We investigated the fate of soil nutrients after centuries of indigenous dryland agriculture in Hawai‘i using a coupled geochemical and archaeological approach. Beginning 500 years ago, farmers began growing dryland taro and sweet potato on the leeward slopes of East Maui. Their digging sticks pierced a subsurface layer of cinders, enhancing crop access to the soil water stored below the intact cinders. Cultivation also catalyzed nutrient losses, directly by facilitating leaching of mobile nutrients after disturbing a stratigraphic barrier to vertical water movement, and indirectly by increasing mineral weathering and subsequent uptake and harvest. ...

Geoengineering potential of artificially enhanced silicate weathering of olivine

Geoengineering is a proposed action to manipulate Earth’s climate in order to counteract global warming from anthropogenic greenhouse gas emissions. We investigate the potential of a specific geoengineering technique, carbon sequestration by artificially enhanced silicate weathering via the dissolution of olivine. This approach would not only operate against rising temperatures but would also oppose ocean acidification, because it influences the global climate via the carbon cycle. If important details of the marine chemistry are taken into consideration, a new mass ratio of CO2 sequestration per olivine dissolution of about 1 is achieved, 20% ...

Global Soil Nutrient Depletion and Yield Reduction

Nutrient depletion in soils adversely affects soil quality and reduces crop yield and consequently poses a potential threat to global food security and agricultural sustainability. With an emphasis on human-induced nutrient depletion, this paper described the causality among soil nutrient depletion, soil quality, crop production, socio-economic variables, and environmental condition. Then, global soil nutrient budgets of nitrogen (N), phosphorus (P), and potassium (K) were estimated for wheat (Triticum aestivum L.), rice (Oryza sativa), maize (Zeamays L.), and barley (Hordeum vulgare) production for the year 2000. As a result, there were unbalanced ...

Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon‐negative H2 production

Greg H. Rau, Susan A. Carroll, William L. Bourcier, Michael J. Singleton, Megan M. Smith, and Roger D. Aines Abstract We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105 fold increase in OH− concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After ...