Agricultural activity

National Agricultural Library database general coverage of U.S. agriculture active components of agrochemicals... 

Isoxazoles represent a large group of compounds, a number of which display interesting medicinal or agricultural activity or have some other industrial utility. 

By number count the great majority of particles in the outside air are likely to be less than 1 pm. By weight, these small particles will account for a very small proportion of the sample. A filter with a high efficiency measured by weight of particles trapped may be almost transparent to the small ones. Very high counts can be found in rural areas from pollen or agricultural activities. 

Many malodorous compoimds are not only nuisance, but also a health threat under prolonged exposure [1]. Ammonia (NH3) is emitted from landfill and sewage treatment plant and associated with many agricultural activities (e.g. poultry and piggery). Ammonia is also a problem in public toilets, hospitals and nursing homes. Selective eatalytie oxidation (SCO) can convert NH3 to N2 at mild temperature (i.e. 473-673 K) as shown in equation 1, however nitrous oxides (N2O) and nitrogen oxides (NOj) are often produced cf. Eqn. 2 3). 

Semi-arid areas (0.20 < P/PET < 0.50) highly seasonal rainfall regimes and mean annual values up to about 800 mm in summer rainfall areas and 500 mm in winter regimes. Inter-annual variability is nonetheless high (25-50%) so despite the apparent suitability for grazing of semi-arid grasslands, this and other sedentary agricultural activities are susceptible to seasonal and inter-annual moisture deficiency. 

Among these regions is the Ebro River, the Spain s most voluminous and important river in the country. With 910 km, the river accounts for approximately 6% of all riverine waters entering the Mediterranean and drains approximately one-sixth of the Iberian Peninsula, including important urban and industrial areas [3]. But because it is highly exploited by industrial and agricultural activities, the Ebro River basin is the focus of several scientific studies [4-10]. 

This high agriculture activity compromises the chemical and ecological status of the Ebro delta. Pesticides used in the area migrate into the delta building up, together with the pollution produced by some industries, a contamination that can be dangerous to its both fauna and flora, and this contamination increases when water from the rice fields is drained into the delta [17]. 

In another AT study, Terrado et al. [15] characterised pollution patterns in different parts of the Ebro catchment. In the upper part of the Ebro, pollution was found to be mainly in the form of heavy metals (Zn, Cu, Cr, Pb, Cd and Hg), polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs) and trichlorobenzenes (TCBs). Etrophic conditions were also found. Pollution was found to source mainly from industry and urbanisation. The central Ebro was characterised by nutrient pollution such as the accumulation of Ca, Na, Mg and K, which highlighted the importance of salinisation effects from intensive irrigation and soils with high salt content. In the lower Ebro, organic [DDTs, hexachlorobenzene (HCB) and hexachlorobutadiene (HCBu)] and heavy metal (Hg, Cd, Zn and As) contamination was found to derive mainly from industrial and agricultural activities. 

Large quantities of arsenicals are released into the environment as aresult of industrial and especially agricultural activities, and these may pose potent ecological dangers. 

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