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Ocean acidification effects on in situ coral reef metabolism

Steve S. Doo, Peter J. Edmunds & Robert C. Carpenter Abstract The Anthropocene climate has largely been defined by a rapid increase in atmospheric CO2, causing global climate change (warming) and ocean acidification (OA, a reduction in oceanic pH). OA is of particular concern for coral reefs, as the associated reduction in carbonate ion availability impairs biogenic calcification and promotes dissolution of carbonate substrata. While these trends ultimately affect ecosystem calcification, scaling experimental analyses of the response of organisms to OA to consider the response of ecosystems to OA has proved difficult. The benchmark of ecosyst...

Effectiveness of enhanced mineral weathering as a carbon sequestration tool and alternative to agricultural lime: An incubation experiment

Christiana Dietzen, Robert Harrison, Stephani Michelsen-Correa Abstract Applying finely ground silicate minerals to soils could mitigate CO2 emissions by enhancing the rate of carbon sequestration via silicate weathering. Using these minerals instead of agricultural lime to increase soil pH would also eliminate the dissolution of lime as a major source of agricultural CO2 emissions. However, dissolution rates of silicate minerals in the soil environment are uncertain and impacts of their application on the decomposition of soil organic matter have yet to be determined. A 3-month soil incubation was performed to investigate the effects ...

Changes in USDA food composition data for 43 garden crops, 1950 to 1999

Donald R Davis 1, Melvin D Epp, Hugh D Riordan Summary Objectives: To evaluate possible changes in USDA nutrient content data for 43 garden crops between 1950 and 1999 and consider their potential causes. Methods: We compare USDA nutrient content data published in 1950 and 1999 for 13 nutrients and water in 43 garden crops, mostly vegetables. After adjusting for differences in moisture content, we calculate ratios of nutrient contents, R (1999/1950), for each food and nutrient. To evaluate the foods as a group, we calculate median and geometric mean R-values for the 13 nutrients and water. To evaluate R-values for individual foods and ...

Declining Fruit and Vegetable Nutrient Composition: What Is the Evidence?

Donald R. Davis Abstract Three kinds of evidence point toward declines of some nutrients in fruits and vegetables available in the United States and the United Kingdom: 1) early studies of fertilization found inverse relationships between crop yield and mineral concentrations—the widely cited “dilution effect”; 2) three recent studies of historical food composition data found apparent median declines of 5% to 40% or more in some minerals in groups of vegetables and perhaps fruits; one study also evaluated vitamins and protein with similar results; and 3) recent side-by-side plantings of low- and high-yield cultivars of broccoli and grains ...

Food Patterns Equivalents Intakes by Americans: What We Eat in America,

Shanthy A Bowman, Natalia Schroeder, Randy P LaComb Abstract The 2015-2020 Dietary Guidelines for Americans (DGA) encourage Americans to increase their fruit, vegetables, and whole grains intakes and limit added sugars and solid fats intakes [1]. This report highlights the salient changes in the U.S. population’s intake of selected USDA Food Patterns groups, including added sugars and solid fats, using What We Eat in America, NHANES 2003-2004 and 2015-2016 dietary data [2-4]. Download

Forest soil carbon is threatened by intensive biomass harvesting

David L. Achat, Mathieu Fortin, Guy Landmann, Bruno Ringeval & Laurent Augusto Abstract Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers’ decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused ...

Local fertilizers to achieve food self-sufficiency in Africa

Davide Ciceri, Antoine Allanore Abstract One of the key Sustainable Development Goals (SDG) set by the United Nations (UN) aims by 2030 to “end hunger, achieve food security and improved nutrition and promote sustainable agriculture”. Fertilizers will play a pivotal role in achieving that goal given that ~90% of crop production growth is expected to come from higher yields and increased cropping intensity. However, materials-science research on fertilizers has received little attention, especially in Africa. In this work we present an overview of the use of fertilizers in Africa to date, and based on that overview we suggest future research ...

The effect of time on the weathering of silicate minerals: why do weathering rates differ in the laboratory and field?

Art F.White, Susan L.Brantley Abstract The correlation between decreasing reaction rates of silicate minerals and increasing duration of chemical weathering was investigated for both experimental and field conditions. Column studies, using freshly prepared Panola Granite, produced ambient plagioclase weathering rates that decreased parabolically over 6 years to a final rate of 7.0* 10^-14 mol m^-2 s^-1  1. In contrast, the corresponding plagioclase reaction rate for partially kaolinized Panola Granite, after reaching steady-state weathering after 2 months of reactions, was significantly less (2.1 *10^-15 mol m^-2 s^-1). Both rates were ...

The use of rocks to improve family agriculture in Brazil

Suzi H. Theodoro, Othon H. Leonardos Abstract During the second half of the 20th century, the introduction of new chemical agriculture technologies brought about a revolution in food production, but this has also cause deep deterioration in our relationships with the natural environment. In developing tropical countries, record yields were accompanied by rural exodus, widespread deforestation and loss of topsoil. The stonemeal research described herein is an alternative to such practices as it is an environmental friendly and socially responsible technology based on soil rejuvenation and conservation by means of the addition of natural rock ...

Rocks as fertilizers: preliminary studies on potassium availability of some common rocks in Sri Lanka

J. M. NIWAS and C. B. DISSANAYAKE Abstract Preliminary investigations of the K availability of some commonly occurring rocks of Sri Lanka showed that granulitic gneiss, pink granite, migmatitic gneiss and microcline granite release relatively high amounts of K indicating the capability of using these to provide K in plant nutrition. The finer crushed sizes are more effective in releasing K, and the availability of the K-reserves under appropriate soil conditions makes them possible substitutes for synthetic K fertilizers. Download