Naslov
Nitrates and Ammonia in the Waters of a Part of the Drava River Basin

Autori
Mihalić, Aleksandra ; Vidaček, Željko ; Sraka, Mario

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings / J. Steenvoorden - Wageningen, 2000, 92-93

Skup
International Conference on Agricultural Effects on Ground and Surface waters

Mjesto i datum
Wageningen, Nizozemska, 01.10.2000. - 04.10.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
nitrates; ammonia; groundwater; drainage; surface waters

Sažetak
Stationary investigations of the pollution of surface and ground waters with nitrates and ammonia were carried out during the 1992-1998 research period in a part of the Drava-Danube catchment area in the Republic of Croatia. The participation of the nitrate form of nitrogen in waters is higher than that of ammonia due to its greater motility in soil, and lesser possibility of its being adsorpted to the solid soil phase. Numerous studies have confirmed the dependence of nitrate leaching from soil on the soil texture, plant uptake, nitrification and denitrification processes, rainfall amount and fluctuation, evapotranspiration, fertilization and drainage of soil (Ercoli et al., 1989; Ange et al., 1993; Campbell et al., 1994; Vidaček et al., 1999). Quality of ground, drainage and surface water was studied on five locations (Kapelna, Suvar, Lila, Topolak and Petrovac) during period 1992-1996, and during period 1997-1998 only on one location - Kapelna. Soils involved in investigations were: hydroameliorated eugley (Gleysols, FAO 1990) - Kapelna, Lila and Topolak, non saline-alkali soil (Solonetz, FAO 1990) - Suvar, hydroameliorated pseudogley-gley (Gleyic Podzoluvisols, FAO 1990) - Petrovac. Standard agrotechnical measures were applied on all locations including nitrogen fertilization from 87 to 198 kg N/ha. Different rates and kinds of nitrogen fertilization (nitrate, ammonium and amid form of nitrogen) were applied depended on field crops - sunflower, soybean, winter barley, winter wheat, sugarbeet and corn.Nitrates and ammonia in waters were determined according to methods of Chapman and Pratt. Measuring of concentrations of nitrate and ammonia were conducted by spectrophotometric method on PYE UNICAM 8600 UV/VIS. Nitrate concentrations determined in ground waters ranged from 0.6 to 91.6 mg NO3-/l, from 31.0 to 171.1 mg NO3-/l in drainage waters, from 1.2 to 74.2 mg NO3-/l in surface waters of canals, and from 0.4 to 39.8 mg NO3-/l in the rivers Karašica and Vučica. The highest concentrations of nitrate in waters were determined in cold, non-vegetative period with larger rainfall amount and after fertilization. The ammonium form of nitrogen ranged from 0.03 to 14.4 mg NH4+/l in ground waters, from 0.02 to 5.84 mg NH4+/l in drainage waters, from 0.02 to 8.91 mg NH4+/l in canal waters, and from 0.01 to 3.0 mg NH4+/l in the rivers Karašica and Vučica. Ammonia concentrations in waters were much more lower than that of nitrate due to its smaller motility in soil and better posibility of its being adsorpted on solid soil phase. Nitrate concentrations in ground, drainage and surface waters occasionally surpassed the maximum allowed concentrations (MAC) for all water classes in the non-growing, wet and cold period, while ammonia concentrations in all waters were higher than MAC in waters of classes I and II, but did not exceed MAC in waters of classes III-V according to Croatian Regulatory Act, N.N. 78/98. According to the research results, water pollution by nitrates appears especially in the wet winter-spring period, when the conditions favour nitrogen leaching. Correction and adjustment of nitrogen application especially to winter crops is recommended, taking account of the rates and kinds of nitrogen fertilizers, as well as of their application time.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA