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Agricultural workers in Chile: Situations an opinions
1997
Ziche, J. | Rojas, A. | Sauer, U. | Stallmeister, P. (Technische Univ., Muenchen, Freising (Germany). Inst. fuer Wirtschafts- und Sozialwissenschaften des Landbaues)
Agricultural workers live under precarious social conditions. Their expectations exhibit no illusion about their future. | Landarbeiter leben unter schlechten sozialen Bedingungen. Bei der Analyse der Situation wird sichtbar, dass sie keine illusionaeren Zukunftsvorstellungen hegen.
Afficher plus [+] Moins [-]Agricultural development in Sub Saharan Africa: an engineer's perspective
1997
Mrema, G.C. (Association for Strengthening Agricultural Research in Eastern and Central Africa, Entebbe (Uganda))
Agricultural plant growing in Hungary - Change of an era
1997
Bocz, E. (Debrecen Univ. of Agric., Debrecen (Hungary))
Nitrogen Balance in and Export from an Agricultural Watershed Texte intégral
1997
David, Mark B. | Gentry, Lowell E. | Kovacic, David A. | Smith, Karen M.
Surface water nitrate (NO⁻₃) pollution from agricultural production is well established, although few studies have linked field N budgets, NO⁻₃ loss in tile drained watersheds, and surface water NO⁻₃ loads. This study was conducted to determine field sources, transport, and river export of NO⁻₃ from an agricultural watershed. The Embarras River watershed at Camargo (48 173 ha) in east-central Illinois was investigated. The watershed is a tile-drained area of fertile Mollisols (typical soil is Drummer silty clay loam, a fine-silty, mixed mesic Typic Haplaquoll) with primary cropping of maize (Zea mays L.) and soybean (Glycine max L.). Agricultural field N sources and sinks, tile drainage NO⁻₃ concentrations and fluxes, and river NO⁻₃ export were estimated for the entire watershed. Large pools of inorganic N were present following each harvest of maize and soybean (average of 3670 Mg N yr⁻¹ over a 6-yr period). The source of most of the inorganic N was divided between N fertilizer and soil mineralized N. High concentrations of NO⁻₃ were found in four monitored drainage tiles (5–49 mg N L⁻¹), and tile concentrations of NO⁻₃ were synchronous with Embarras River NO⁻₃ concentrations. High flow events contributed most of the yearly NO⁻₃ loss (24.7 kg N ha⁻¹ yr⁻¹) from tile drained fields in the 1995 water year (1 Oct. 1994 through 30 Sept. 1995) where high rainfall events occurred in a low overall precipitation year (in one tile 21% of the annual load was exported in 1 d). During the 1996 water year, NO⁻₃ export in tiles was much higher (44.2 kg N ha⁻¹ yr⁻¹) due to greater precipitation, and individual days were less important. On average, about 49% (average of 1688 Mg N yr⁻¹ over a 6-yr period) of the field inorganic N pool was estimated to be leached through drain tiles and seepage and was exported by the Embarras River, although depending on weather and field N balances this ranged from 25 to 85% of the field N balance over the 6-yr period. It seems likely that agricultural disturbance (high mineralization inputs of N) and N fertilization combined with tile drainage contributed significantly to NO⁻₃ export in the Embarras River.
Afficher plus [+] Moins [-]ICT adoption in agriculture: an agricultural software-review perspective
1997
Gelb, E.M. | Bonati, G. | Carel, J.L. | Claustriaux, J.J. | Jurgens, P. | Lehnert, S. | Pasher, P. | Kamp, J.A.L.M. | Mourao, A.M. | Wahl, V. | Nicol, J. | Butragueno, J.A.N. | Costa, F. | Spoiden, G. | Raschas, M.
Research of an agricultural technology sector in a complexion of an informatics system make
1997
Wojciechowski, H. (Przemyslowy Instytut Maszyn Rolniczych, Poznan (Poland))
Results of the first stages of research and design works connected with the constitution of integrated information system for agricultural engineering are presented in the paper. The basic groups of potential users and the information fields of the system are also characterized. The paper shows the results of questionnaire research of chosen groups of the future system users in order to know what is the real degree of informatics application in their firms
Afficher plus [+] Moins [-]Agricultural policy reform in the United States: an unfinished agenda
1997
Stuart, K. | Runge, C.F. (Department of Applied Economics, University of Minnesota (USA))
Nitrogen and pesticide concentrations in an agricultural basin in north-central Connecticut
1997
Mullaney, John R. | Zimmerman, Marc James
An analytical economic study for waste in Egyptian agricultural land resources
1997
Mostafa, N.A. | Fahmy, I.S.I. (Alexandria Univ. (Egypt). Faculty of Agriculture)
The study uses descriptive and quantitative statistical methods to estimate the waste in agricultural area and loss in soil productivity. The results shows that average in area is about 54.84 thousand feddans annually, and that the loss in productivity is about 56.9 thousand feddans annually
Afficher plus [+] Moins [-]Biodiversity evaluation in agricultural landscapes: an approach at two different scales
1997
Duelli, P. (Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland). Div. of Landscape Ecology)
