VIDACEK zeljko, BOGUNOVIC Matko, SRAKA Mario, HUSNJAK Stjepan, MIHALIC Aleksandra

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1 Scientific registration n o : 844 Symposium n o : Presentation: poster Triazine herbicides in drained soils and water in the part of river Drava catchment area Herbicides de type triazine dans les eaux et les sols drainés du bassin versant de la rivière Drava (Croatie) VIDACEK zeljko, BOGUNOVIC Matko, SRAKA Mario, HUSNJAK Stjepan, MIHALIC Aleksandra Soil Science Department of Faculty of Agriculture University of Zagreb, Svetoš imunska, Zagreb, Croatia Introduction Rational use and conservation of land and water resources is the national and strategic objective of sustainable development and the fundamental precondition of survival of humankind on Earth. Recently, intensive agricultural production has resulted in the growing human influence on agroecosystems through various agroamelioration and hydroamelioration measures such as drainage, irrigation, deeper and more frequent ploughing, and in particular ameliorative fertilization and intensive use of protective chemicals - pesticides. Triazine herbicides are chemical components used in the last thirty years as agrochemical agents in weed control. Due to their persistence and their frequent application they have become an important factor in pollution of the soil, as well as of surface, ground and drain water where they get after being applied on soil surface. They may also be detected in rainwater, where they get by evaporation during and immediately after application. In spite of their frequent application, no systematic observation nor monitoring of the level of these compounds in agroecosystems in Croatia had been carried out before 99. It was one of the reasons of initiating, in early 99, the stationary research of the impact of agroamelioration and hydroamelioration measures on the level of pollution in drained soils and water in the lowland area of the Drava river - the catchment areas of the Karaš ica and Vuèica rivers. Materials and methods During the five-year period (99-) triazine herbicides atrazine and simazine were analyzed in soil, as well as in ground, surface and drain water in the lowland area of the Drava river, in the part of the Karaš ica and Vuèica catchment area. The soils analyzed were drained amphigley (Gleysols, FAO 99) and drained nonsalinated alkaline soil (Solonetz, FAO 99).

2 On drained amphigley, the trial field Kapelna was organized with two variants of drain spacing, m on Variant A, and 4 m on Variant B. The drain diameter was 8 mm, the depth m, and the drain slope was.. Hydropedological piezometers were placed at depths from. to. m for control of shallow ground water. In the period from 99 to the following crops were grown on the Kapelna trial field: sunflower and soybean, winter barley, winter wheat and sugarbeet, with application of standard agrotechnical measures for each crop. With regard to the cropping pattern no triazine herbicides were used during the research period. However, in 99, treating of maize was carried out by the herbicide Radokor with simazin as the active substance, in the standard quantity of. l/ha. Close to the Kapelna trial field, hydrogeological piezometers were placed at the depth of. m for the control of deep ground water of the loess aquifer. On the nonsalinated alkaline soil the trial field Suvar was organized with two variants of drain spacing, m on Variant A, and m on Variant B, and the drain depth was about. m. Hydropedological piezometers were placed on the depth between. and. m. From 99 to the following crops were grown on the trial field Suvar: soybean, maize, winter wheat and sunflower, with application of standard agrotechnical measures for each crop. In 99, protection of maize was carried out with Radokor, with simazine as the active substance in the quantity of. l/ha, while in, protection of maize was carried out with Radazin using atrazine as the active substance in the quantity of. l/ha. Concentrations of atrazine and simazine in the arable layer were obtained by extraction with the mixture of acetone and hexan (:) in the ultrasonic bath. e and simazine in water were determined by the procedure involving pouring of octadecisillicondioxide over the sample, treating by acetone, evaporation and extraction of water precipitate by n-hexan. The quantitative gas-chromatography analysis of the prepared samples was carried out on the capillary coloumn Suplecowax TM,, mm x. mm with alkaline fameionic detector. The detection limits for triazine herbicides in soil were during the laboratory analysis lowered from to ng/g for atrazine, and from to 4 ng/g for simazine. The detection limits for triazine herbicides in water were also lowered from. to. µg/l for atrazine, and from. to. µg/l for simazine. Results and discussion In soils and water of the trial fields Kapelna and Suvar, during the five-year research period from 99 to concentrations of simazine and atrazine were monitored. Concentrations of atrazine in drained amphigley soil (Gleysols, 99) of the trial field Kapelna were up to 8 ng/g on Variant A with smaller drain spacing and up to ng/g on Variant B with larger drain spacing, while the simazine concentrations were up to 8 ng/g on Variant A and up to 6 ng/g on Variant B, Table.

3 Table. Concentrations of triazine herbicides in soil on Kapelna trial field VARIANT A VARIANT B Year Date Depth Concentration in soil, ng/g Concentration in soil, ng/g cm e e e e < < < < <. - < < < < < < 4 < < < < 4 < < 4 Maximum atrazine concentrations recorded in drained nonsalinated alkaline soil (Solonetz, 99) on the trial field Suvar were 47 ng/g on Variant A with smaller drain spacing and 9 ng/g on Variant B with larger drain spacing, while the simazine concentrations were 7 ng/g on Variant A, and 9 ng/g on Variant B, Table. Table. Concentrations of triazine herbicides in soil on Suvar trial field VARIANT A VARIANT B Year Date Depth Concentration in soil, ng/g Concentration in soil, ng/g cm e e e e < 9 <. - 6 < < < < 4 < < < < 4 < < < < 4 < < < < 4 < < 4 Higher concentrations of simazine in soil, recorded only in on both trial fields may be the effect of crop treating by simazine-based herbicide in 99, (. l/ha and. l/ha, respectively), air spraying of herbicide over the surrounding fields, or may be introduced by rainwater. Higher concentrations of atrazine in soil on the trial field Suvar, detected on both variants on July,, are the effect of regular maize treatment by herbicide Radazin in the previous year. Concentrations of atrazine detected on the same variants on October,, indicate considerable reduction of atrazine content in soil due to decomposition and/or migration of atrazine from soil. In surface waters of the Karaš ica and the Vuèica rivers simazine concentrations are most frequently below detection limits, with maximum values of, µg/l. Maximum atrazine concentrations detected in surface water of the same rivers are.79 µg/l for the Karaš ica, and.86 µg/l for the Vuèica, Graphs and. Higher concentrations of analyzed herbicides in separate years are the result of intensive application of protective chemicals on 4,8 ha of agricultural land in the Karaš ica and Vuèica catchment area.

4 Graph : Concentrations of triazine herbicides in water of river Karaica,8,7,6,,4,,, Graph : Concentrations of triazine hebicides in water of river VuŁica,,, Concentrations of atrazine and simazine in deep ground water from hydrogeological piezometers near the trial field Kapelna are shown in Graph. 4, 4 Graph : Concentrations of triazine herbicides in ground water of hidrogeological piezometers near trial field Kapelna,,,, The maximum atrazine content in deep ground water from hydrogeological piezometers in the vicinity of the trial field Kapelna is 4.97 µg/l, while the simazine content does not exceed. µg/l. In drain water of the trial field Kapelna the recorded atrazine concentrations are slightly above detection limits, while simazine has not been detected, Table. Table. Concentrations of triazine herbicides in drain water on trial field Kapelna Year Date Concentration in water, µg/l e e 99.. <. <... <. < <... <. < <. 4

5 In shallow ground water of the trial field Kapelna the highest concentrations of simazine of.77 µg/l were recorded in late September 99, while in the other samples they are below detection limits. Concentrations of atrazine vary within the range from.7 µg/l to 6.4 µg/l, Graph 4. During the research period triazine herbicides were not applied, and considerable concentrations of atrazine and simazine were recorded only in 99 as the result of their regular application in the previous years. In the rest of the research period there is evident reduction below detection limits. Graph 4: Concentrations of triazine herbicides in ground water of hidropedological piezometers on trial field Kapelna During the research period on the trial field Suvar ground and drain water analysis was carried out. With respect to application of Radazine in spring, its maximum concentration in shallow ground water of 8.7 µg/l in June is understandable. However, already in winter of the same year its concentration was reduced below. µg/l due to its degradation. In the remaining part of the research period minimum concentrations of atrazine were recorded in shallow ground water. Concentrations of simazine in shallow ground water on the trial field Suvar show a similar falling trend during the research period, like simazine concentrations in shallow ground water of the trial field Kapelna, Graph. Graph : Concentrations of triazine herbicides in ground water of hidropedological piezometers on trial field Suvar In drain water of the trial field Suvar the recorded concentrations of atrazine are slightly above detection limits, while simazine has not been detected, Table 4. Table 4. Concentrations of triazine herbicides in drain water of the trial field Suvar Year Date Concentration in water, µg/l e e 99.. <. <....8 <.... <. 9.. <. <.

6 During the research period in the soils of the trial fields Kapelna and Suvar minimum concentrations of atrazine and simazine were detected. Larger deviations occur on the trial field Suvar in after application of the herbicide Radazin. However, even in that year concentrations of atrazine in soil do not exceed µg/l which is considered the upper limit of tolerance for sensitive crops in the cropping pattern (Šilješ, 977). Concentrations of atrazine and simazine in analyzed samples of surface and ground water reach 8,7 µg/l for atrazine, and.77 µg/l for simazine, which is considerably above the maximum allowable concentrations of single pesticides in drinking water, i.e.. µg/l according to the Croatian legislation (8) and European Union Guidelines (). Even compared to the more liberal criteria of the US Environmental Protection Agency, these concentrations of atrazine and simazine in surface and ground water exceed the allowed concentrations in drinking water of µg/l for atrazine (4) and µg/l for simazine (). Conclusions During the five-year stationary research from 99 to in the Drava river basin in the Republic of Croatia the authors analyzed the impact of triazine herbicides, atrazine and simazine, on the quality of ameliorated soils and water during regular crop production. On drained amphigley (Gleysols, FAO 99) and on nonsalinated alkaline soil (Solonetz, FAO 99) the detected concentrations of atrazine and simazine are generally slightly above detection limits, i.e. - ng/g for atrazine, and -4 ng/g for simazine. The highest concentrations of atrazine in soil of 9 ng/g were determined on nonsalinated alkaline soil (Solonetz) in after application of atrazine-based herbicide. In the water of the Karaš ica and the Vuèica rivers, as well as in ground water on both trial fields, the determined concentrations of atrazine and smazine were often above the maximum allowable concentrations for drinking water of. µg/l according to the Croatian and EU legislation. Maximum determined concentrations of atrazine in surface water of the Karaš ica and Vuèica rivers are.86 µg/l, and simazine. µg/l. In deep ground water in the vicinity of the trial field Kapelna, maximum atrazine content is 4.97 µg/l, and simazine content is. µg/l. In shallow ground water of the trial field Kapelna, maximum concentrations recorded were 6.4 µg/l for atrazine and.77 µg/l for simazine, while the maximum concentrations of atrazine in shallow ground water of the trial field Suvar were 8.7 µg/l. The triazine herbicide content in drain water on both trial fields was generally below detection limits, <. -. µg/l for atrazine, and. -. µg/l for simazine. On the basis of the obtained results the authors conclude and recommend rational use of herbicides on intensively cultivated agricultural land in order to protect soil and water from this kind of pollution. Bibliography. Šilješ, I.: Residual herbicides as the limiting factor in production of sensitive crops on soils of IPK Osijek, Tla Slavonije i Baranje, Zagreb, 977. Vidaèek Ž., Drevenkar Vlasta, Husnjak S., Sraka M., Karavidoviæ P.: Nitrates, pesticides and heavy metals in drained solis and water in the Karaš ica and Vuèica 6

7 catchment area, scientific workshop Agriculture and Water Managment, Bizovaèke Toplice, Proceedings 79-9,. xxx EEC Drinking Water Guideline, 8/778/EEC, EEC No L 9--9 August, xxx US Environmental Protection Agency, National Pesticide Survey, e, Office of Pesticides and Toxic Substances: Washington, USA, 99.. xxx US Environmental Protection Agency, National Pesticide Survey, e, Office of Pesticides and Toxic Substances: Washington, USA, FAO Unesco Soil Map of the World, Revised Legend, Rome, Italy, xxx Regulations on protection of agricultural land from pollution by harmful substances, N. N. /9, 74-76, xxx Regulations on sanitary acceptability of drinking water, N. N. 64/94, 69-7, Key words: triazine herbicides, drained soil, water, monitoring Mots clés : herbicides, triazine, sols drainés, eaux, surveillance, pollution, bassin versant, Croatie 7