178 results for group: journal-article

Soil Rejuvenation in Mauritius

Mauritius is a tropical island of volcanic origin. The high altitudes attained lead to wide variation in precipitation. To windward, and on the higher altitudes this precipitation may be very high; to leeward, protected by the intervening heights, low precipitation is found. There is, too, only a slight difference in temperature at all altitudes. In the regions of higher precipitation, therefore, the conditions are favorable for a rapid depletion of the soils and the parent basaltic matrix in such areas has broken down, leaving lateritic soils which are very infertile.

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 ...

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 ...

Silicate production and availability for mineral carbonation

P. Renforth*, C.-L. Washbourne, J. Taylder, and D. A. C. Manning Abstract Atmospheric carbon dioxide sequestered as carbonates through the accelerated weathering of silicate minerals is proposed as a climate change mitigation technology with the potential to capture billions of tonnes of carbon per year. Although these materials can be mined expressly for carbonation, they are also produced by human activities (cement, iron and steel making, coal combustion, etc.). Despite their potential, there is poor global accounting of silicates produced in this way. This paper presents production estimates (by proxy) of various ...