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Résultats 101-110 de 142
[Pollution prevention methods in fast flowing rivers]
1983
Rozas Elgueta, E. (La Serena Univ., Santiago (Chile))
[Nuclear techniques in environmental pollution studies]
1983
Aravena, R. | Cortes, E. | Heresi, N. (Comision Chilena de Energia Nuclear, Santiago (Chile))
[Heavy metals in the marine environment]
1983
Diaz, O. | Aguirre, S.
[Defense of environmental quality in areas of agricultural development]
1983
Moraga C, J. (Servicio Agricola y Ganadero, Santiago (Chile))
[Purification of water discharge using rotating biological filters]
1983
Abeliuk R, R.
Transport of ammonium- and nitrate-nitrogen in surface runoff from pasture as influenced by urea application Texte intégral
1983
Sharpley, A.N. | Syers, J.K. | Tillman, R.W.
The effect of a surface application of urea on the transport of N in surface runoff from permanent pasture in New Zealand was investigated under natural rainfall conditions. Maximum concentrations of NH4- N(3.6 mg l-1) and NO3-N(4.5 mg l-1) in surface runoff were attained 3 and 1 week, respectively, following urea application (60 kg N ha-1). Amounts of NH4-N, NO3-N, and total N transported in surface runoff from unfertilized (1.58, 0.52, and 4.73 kg ha-1 yr-1, respectively) and fertilized pasture (1.74, 1.09, and 8.96 kg ha-1 yr-1)were less than inputs in precipitation (2.09, 3.63, and 10.9 kg ha-1 yr-1), respectively. Amounts of NH4-N, NO3-N, and total N transported in surface runoff were only 0.3, 1.0, and 7.1 % of that applied. The mean annual concentration of NH4-N (0.9 mg l-1) in surface runoff from unfertilized pasture was above the recommended levels for drinking water (0.5 mg l-1) and the mean concentration of NO3-N (0.5 mg l-1) was greater than levels associated with accelerated cutrophication (0.3 mg l-1 ). The practicality of attaining or maintaining N concentrations in surface runoff from fertilized agricultural land below recommended levels is questioned.
Afficher plus [+] Moins [-][Quantification of organochloride substances in water through a method of extraction by vapor scrubbing with recycling over isooctane (MAVRI)]
1983
Ciudad Banda, C. | Moyano A, S.
[Fecal bacterium coli in waters of the Aconcagua River]
1983
Gonzalez M, S. | Bergqvist A, E. | Venegoni L, C. | Insunza, M.
[Proposal of new criteria to classify the suitability of waters in Northern Chile for irrigation use]
1983
Alonso Carvallo, H. (Universidad del Norte, Antofagasta (Chile))
Stimulation of growth in papaya and other plants by dilute salt solutions
1983
Kottenmeier, W. (University of Hawaii, Honolulu, Hawaii (USA). Dept. of Botany) | Chang, H. | Siegel, S.M. | Siegel, B.Z.
