Agricultural impacts

Agriculture activities are one of the major generators of salinity but also one of the first to suffer its damage. The salinity of agricultural return flow is derived from two principal sources salinity of the irrigation water and the effects of added 

Salinity contributes to significant losses of productivity in agricultural land and may take some land entirely out of production. Plant roots absorb water from the soil through the process of osmosis. Osmosis moves water from areas of lower salt concentration to areas of higher concentration. Once the salt concentration gradient is reduced, transport of water to plants is slowed and if extreme conditions of salinity prevail, the osmosis may stop or even change direction, causing plant dehydration. 

Soil salinization is the first stage of environmental destruction caused by sahnity and is related to river and lake salinization. For example, the diversion of the Amu Darya and Syr Darya Rivers caused significant desiccation of the Aral Sea, but it also caused salinization of associated agricultural land (e.g., Funakawa et al. 2000 Spoor 1998). In Australia, soil salinization is the most severe environmental problem on the continent, causing dramatic changes in landscape, industry, and the future of farmland (e.g., Dehaan and Taylor 2002). 

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Keywords Industrial and agricultural impacts, Monitoring campaigns, Sediments, Water... 

Guerschman J.P. and Paruelo J.M. (2005). Agricultural impacts on ecosystem functioning in temperate areas of North and South America. Global and Planetary Change, 47(2-4), 170-180. 

Perhaps one of the earliest and most influential studies that compared the agricultural impact of manual (slash-and-burn) and mechanical (bulldozer) clearing for pasture establishment in the Amazon basin was that of Seubert et al. (1977) in Peru. In that study, pasture (Panicum maximum) biomass produaion, over a 2-year period, was 68 % higher in the area cleared manually. Other studies have followed, with the general conclusion that pastures manually cleared from forest were more productive and that mechanical clearing adversely affected soil physical and chemical properties (e.g., Alegre 1985, Toledo and Morales 1979, Dias and Northcliff 1985). 

Singh, B.R., 1991. Unwanted components of commercial fertilizers and their agricultural impact. Proc. Fertilizer Soc., London, Dec. 1991, pp. 2-28. 

Snow, D.D. Spalding, R.F. "Soluble pesticide levels in the Platte River basin of Nebraska," in Agricultural Impacts on Groundwater Conference, Des Moines, lA., NWWA, 1988, 211-233. 

S.M. Horvath and D.J.McKee (1994). In D.J. McKee, ed.. Tropospheric Ozone Human Health and Agricultural Impacts, CRC Press/Lewis Publishers, Boca Rat[Pg.1199]

Agricultural impacts can also be lessened with the use of less intensive agricultural feedstocks that require less fertilizers, chemicals, and energy. Raw materials for PLA production must have certain properties to be competitive on a large scale with petroleum feedstocks. Such desirable characteristics include renewability, cost competitiveness. 

De La Torre Ugarte, D.G., English, B.C., Jensen, K., 2007. Sixty billion gallons by 2030 economic and agricultural impacts of ethanol and biodiesel expansion. American Journal of Agricultural Economics 89 (5), 1290—1295. 

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