Arable land

For arable land, plus urea emissions from pasture. Based on total UK fertilizer consumption (Asman, 1992) ° and 0.68 agricultural land area as arable and ungrazed grass (MAFF, 1990). ... 

Jjemba PK (2002) The potential impact of veterinary and human therapeutic agents in manure and biosolids on plants grown on arable land a review. Agric Ecosyst Environ 93 267-278... 

Kreuger J, Brink N. 1988. Losses of pesticides from arable land. Vaxtskyddsrapp Jordbruk 49 50-61. 

Muller s formative student years coincided with two dangerous crises caused by a lack of effective insecticides. During World War I, when Muller was in high school, neutral Switzerland suffered from serious food shortages. The country is largely mountainous, and most of its arable land is pasturage. Able to raise only half the grain it needed, Switzerland needed to protect every possible kernel from insects but could not. 

Critchley CNR, Allen D S, Fowbert J A, Mole A C and Gundrey A L (2004). Habitat establishment on arable land assessment of an agri-environment scheme in England, UK . Biological Conservation, 119, 429 142. 

By modelling soil erosion, Pimentel et al. (1995) showed that 30% of the world s arable land was lost from 1955 to 1995. As losses continue by 10... 

Certainly, calculation of the metabolic quotient can reveal trends very different from those of basal respiration. As shown in Fig. 1, for the 7 land uses, trends in basal respiration were broadly similar to those for microbial biomass C and organic C. However, when the metabolic quotient was calculated, trends with land use were very different. Values were greater under sugarcane, maize and to a lesser extent annual ryegrass, than the other treatments. This suggests that the microbial community under these arable land uses is under more stress and/or has a different composition to that under the others. The most likely microbial stress under these land uses is likely to be a shortage of available substrate C. 

Conventional farming systems are often associated with nutrient leaching from arable lands and ground water pollution (Hansen et al. 2000). Application of farm... 

Biomass potentials are mainly determined by agricultural productivity and the amount of land accessible for energy crop production. The total area under energy crops in the EU was around 1.6 million hectares in 2004 (estimate for 2005 2.5 million hectares), which represents nearly 3% of the total arable land. AEBIOM (2007) estimated a total biomass supply of 220 MtOE for the year 2020, while 23 MtOE are covered by wood-based bioenergy (direct from forests) and 88 MtOE by agriculture-based energy crops (by-products not considered). The Commission has estimated that about 15% of the EU s arable land (17.5 million hectares) would be used to reach the targets for 2020. 

Declining amounts of arable land, increasing world populations, and increasing costs of fertilizer and food and energy needs will make it increasingly difficult to maintain our soil resources. A key component for sustaining soil productivity is the maintenance of soil organic carbon (SOC). SOC maintenance requires the amount of carbon added to the system to equal the amount of relic carbon mineralized... 

With respect to soils, a receptor is thus characterized as a specific combination of land use (e g., Forest ecosystem types, agricultural crops) and soil type. The critical loads can be calculated for both agricultural soils (grassland, arable land) with HM inputs with deposition, fertilizers, and wastes, and non-agricultural (forest and steppe) soils, where atmospheric deposition is the only input to the system. 

Possible effects on soil hfe, plants (phytotoxicity) and on ground water are of concern in all types of ecosystems. Food quality criteria are, however, of relevance for arable land only, whereas possible secondary poisoning effects on domestic animals or terrestrial fauna are relevant in grassland and non-agricultural land. A final critical limit can be based on the most sensitive receptor. Even though effects vary for each metal, soil microbes and soil fauna are generally most sensitive. 

The receptors of interest are soils of agricultural (arable lands, grasslands) and non-agricultural (forests, steppes, heath lands, savanna, etc.) ecosystems. In non-agricultural ecosystems, the atmospheric deposition is the only input of heavy metals. Regarding the Forest ecosystems, a distinction should at least be made between Coniferous and Deciduous Forest ecosystems. When detailed information on the areal distribution of various tree species (e.g., pine, fir, spruce, oak, beech and birch) is available, this should be used since tree species influence the deposition and uptake of heavy metals and the precipitation excess. On a world scale, soil types can be best distinguished on the basis of the FAO-UNESCO Soil Map of the World, climate and ecosystem data from NASA database (1989). 

On a global scale, arable lands occupy 12% of the terrestrial ecosystems, and pastures occupy 25%. On the whole, the agrolandscapes occupy 40% of the Earth s land. At present the most used areas are in the moderate climate zone (25%) and subtropical and tropical ones (18%). To the maximal extent, natural landscapes and their relevant biogeochemical cycles are transformed into agrogeochemical provinces with a predominance of agrogeochemical cycles of many elements in Europe (>30%) and Asia (>20%). 

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