California, situated on the Pacific coast of the USA, is the third largest state of the United States in land area and most populous state. The 2009 population...
Greenhouse gas mitigation in agricultureLast Updated on 2014-11-17 12:04:21
Agricultural lands occupy 37% of the Earth’s land surface. Agriculture accounts for 52% and 84% of global anthropogenic methane and nitrous oxide emissions. Agricultural soils may also act as a sink or source for carbon dioxide (CO2), but the net flux is small. Many agricultural practices can potentially mitigate greenhouse gas (GHG) emissions, the most prominent of which are improved cropland and grazing land management and restoration of degraded lands and cultivated organic soils. Lower, but still significant mitigation potential is provided by water and rice management, set-aside, land use change and agroforestry, livestock management and manure management. The global technical mitigation potential from agriculture (excluding fossil fuel offsets from biomass) by 2030, considering all gases, is estimated to be ~5500-6000 megatonnes (Mt) CO2-eq. yr-1, with economic... More »
Agriculture and Greenhouse GasesLast Updated on 2014-11-09 17:57:31
In both industrialized and developing nations, agricultural production of greenhouse gases (GHG) is a significant component of worldwide GHG emissions. There are major contributions to methane production from livestock grazing and rice farming, as well as incomplete combustion of petroleum products in mechanized agricultural equipment. In developing countries agricultural production of greenhouse gases is a much higher percentage of total GHG emissions than for developed countries. For example, rice farming in China and Southeast Asia and livestock grazing in several South American countries contributes proportionately more agricultural GHG than corresponding farming activity in most Western countries. Elimination of overgrazing practises and reduction of dependence of rice farming provide significant opportunities for reducing GHG emissions.
There are also large contributions to... More »
PlantLast Updated on 2014-10-28 12:04:37
A plant is any one of the vast number of organisms within the biological kingdom Plantae; in general, these species are considered of limited motility and generally manufacture their own food. They include a host of familiar organisms including trees, forbs, shrubs, grasses, vines, ferns, and mosses. Conventionally the term plant implies a taxon with characteristics of multicellularity, cell structure with walls containing cellulose, and organisms capable of photosynthesis. Modern classification schemes are driven by somewhat rigid categorizations inherent in DNA and common ancestry.
Throughout most of the history of science from Aristotle to Linnaeus and into the 20th century, species were divided into two kingdoms: animals and plants. Driven by DNA characterizations and other modern analysis, fungi and bacteria have now been removed to separate kingdoms; in particular,... More »
International Food Security Assessment: 2012-22Last Updated on 2014-10-26 16:56:26
Food security is estimated to improve slightly in 2012 as the number of food-insecure people in the 76 countries covered in this report declines from 814 million in 2011 to 802 million in 2012. The share of the population that is food insecure remains at 24 percent. Over the next decade, the share of the population that is food insecure is projected to decline from 24 percent in 2012 to 21 percent in 2022, but the number of food insecure people is projected to increase by 37 million. Regionally, food insecurity is projected to remain most severe in Sub-Saharan Africa. Food-insecure people are defined as those consuming less than the nutritional target of roughly 2,100 calories per day per person.
The U.S. Department of Agriculture's Economic Research Service (ERS) has, since the late 1970s, reported annually on food security in a number of developing countries. A key... More »
HerbicideLast Updated on 2014-10-26 16:45:24A herbicide is any of a number of chemical substances intended to kill vegetation. Since the vast majority of herbicides are non-selective in their lethal action, there may be widespread adverse ecological consequences from their use. These outcomes include not only organism death, but may involve mutagenic, developmental and carcinogenic effects to animals and plants.
Herbicides are in broad use for agriculture, golf courses, utility corridors, residential and other land uses. The earliest herbicides were inorganic chemical substances, although modern herbicides are dominated by organic compounds. Presently, there is massive application of chemical herbicides; in the USA alone 480 million kilograms are applied annually.
Widespread herbicide use beginning in the 1940s is responsible for numerous species extinctions, including birds, amphibians, fish and arthropods. In many cases,... More »
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