16 results for group: d-a-c-manning


Testing the ability of plants to access potassium from framework silicate minerals

The availability of K, essential for plant growth, from syenite (a silicate rock in which potassium feldspar is the dominant mineral; N 90 wt%), and phlogopite mica has been demonstrated using carefully designed plant growth pot experiments in which the only added source of K was the mineral of interest, with no loss of nutrients through drainage. Using pure quartz sand as a soil, both growth (increase in diameter) of leek plants and K-content of the plant material showed a dose-dependent positive response to the application (114–43000 mg K/pot) of milled syenite with increases in plant diameter of 0.5–0.7 mm/week, increasing with applic...

Investigating carbonate formation in urban soils as a method for capture and storage of atmospheric carbon

This paper investigates the potential for engineered urban soils to capture and store atmospheric carbon (C). Calcium (Ca) and magnesium (Mg) bearing waste silicate minerals within the soil environment can capture and store atmospheric C through the process of weathering and secondary carbonate mineral precipitation. Anthropogenic soils, known to contain substantial quantities of Ca and Mg-rich minerals derived from demolition activity (particularly cement and concrete), were systematically sampled at the surface across a 10 ha brownfield site, Science Central, located in the urban centre of Newcastle upon Tyne, U.K. Subsequent analysis ...

Soil Health and Related Ecosystem Services in Organic Agriculture

Soil health is dependent upon complex bio-physical and bio-chemical processes which interact in space and time. Microrganisms and fauna in soil comprise highly diverse and dynamic communities that contribute, over either short or long time frames, to the transformation of geological minerals and release of essential nutrients for plant growth. Certified organic soil management practices generally restrict the use of chemically-processed highly soluble plant nutrients, leading to dependence on nutrient sources that require microbial transformation of poorly soluble geological minerals. Consequently, slow release of nutrients controls their rate ...

Assessing the potential of soil carbonation and enhanced weathering through Life Cycle Assessment: A case study for Sao Paulo State, Brazil

Enhanced silicate rock weathering for long-term carbon dioxide sequestration has considerable potential, but depends on the availability of suitable rocks coupled with proximity to suitable locations for field application. In this paper, we investigate the established mining industry that extracts basaltic rocks for construction from the Parana Basin, Sao Paulo State, Brazil. Through a Life Cycle Assessment, we determine the balance of carbon dioxide emissions involved in the use of this material, the relative contribution of soil carbonation and enhanced weathering, and the potential carbon dioxide removal of Sao Paulo agricultural land ...

Rock dust, crop nutrition and climate change

Soils are the interface between the geosphere and the biosphere. They provide the minerals required for crop nutrition, and they regulate atmospheric CO2 to a greater extent than the ocean. These functions are often treated separately, with studies focusing on either crop nutrition or on soil organic carbon. The use of silicate rocks as remineralizers addresses both functions. Weathering releases nutrients, including silica, for crop growth, and consumes atmospheric CO2, generating bicarbonate in solution. If enough Ca is released, and with sufficient bicarbonate in solution, pedogenic calcite forms as a permanent sink for atmospheric CO2. ...

How will minerals feed the world in 2050?

By 2050, the world’s population will have reached 9 billion. To feed that many people, soil fertility will have to be maintained artificially. All fertiliser materials depend on a geological resource: nitrogen (N) fertilizer production needs fossil fuels, and both phosphate (P) and potassium (K) are derived by mining. Irrespective of new biological techniques in plant breeding and genetic modification, soils still need to supply the mineral nutrients that plants require, and these are exported from soil with every harvest. Studies of global offtake of N, P and K from soils through crop production show that although N and P are roughly in ...

Historical and technical developments of potassium resources

The mining of soluble potassium salts (potash) is essential for manufacturing fertilizers required to ensure continuous production of crops and hence global food security. As of 2014, potash is mined predominantly in the northern hemisphere, where large deposits occur. Production tonnage and prices do not take into account the needs of the farmers of the poorest countries. Consequently, soils of some regions of the southern hemisphere are currently being depleted of potassium due to the expansion and intensification of agriculture coupled with the lack of affordable potash. Moving away from mined salts towards locally available resources of ...

Carbonate Precipitation in Artificial Soils Produced from Basaltic Quarry Fines and Composts: An Opportunity for Passive Carbon Sequestration

The proportions of different carbon pools within artificial soils prepared by blending composts with dolerite and basalt quarry fines has changed over a period of 7 years, accumulating inorganic carbon as carbonate minerals newly formed within the soils. With no artificial energy inputs following construction, this is regarded as a passive mineral carbonation process. Carbon isotope data show that up to 40% of the carbon within the soil carbonate is derived from photosynthesis, mixed with carbon from geological sources (limestone present in the quarry fines). Organic matter within the soils shows very variable composition, with an apparent ...

Biological Enhancement of Soil Carbonate Precipitation: Passive Removal of Atmospheric CO2

Soils are the dominant terrestrial sink for carbon, containing three times as much C as above-ground plant biomass, and acting as a host for both organic and inorganic C, as soil organic matter and pedogenic carbonates, respectively. This article reviews evidence for the generation within the soil solution of dissolved C derived from plants and recognition of its precipitation as carbonates. It then considers the potential value of this process for artificially-mediated CO2 sequestration within soils. The ability of crops such as wheat to produce organic acid anions as root exudates is substantial, generating 70 mol/(y kg) of exuded C, ...

Carbonate Precipitation in Artificial Soils as a Sink for Atmospheric Carbon Dioxide

Turnover of C in soils is the dominant flux in the global C cycle and is responsible for transporting 20 times the quantity of anthropogenic emissions each year. This paper investigates the potential for soils to be modified with Ca-rich materials (e.g. demolition waste or basic slag) to capture some of the transferred C as geologically stable CaCO3. To test this principal, artificial soil known to contain Ca-rich minerals (Ca silicates and portlandite) was analysed from two sites across NE England, UK. The results demonstrate an average C content of 30±15.3 Kg C m^-2 stored as CaCO3, which is 3 times the expected organic C content and that ...