414 Barbara Wiśniowska-Kielian and Kazimierz Klima It has been a common conviction that organic farming is more environment-friendly than the conventi

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1 ECOLOGICAL CHEMISTRY AND ENGINEERING Vol. 14, No Barbara WIŚNIOWSKA-KIELIAN* and Kazimierz KLIMA** COMPARISON OF CADMIUM AND LEAD CONTENTS IN SOIL AND GRAIN OF WINTER WHEAT FROM ORGANIC AND CONVENTIONAL FARMS PORÓWNANIE ZAWARTOŚCI KADMU I OŁOWIU W GLEBIE I ZIARNIE PSZENICY OZIMEJ Z GOSPODARSTW EKOLOGICZNYCH I KONWENCJONALNYCH Summary: : Quality of s and winter wheat from organic and conventional farms from the Małopol- ska district were compared on the basis of their cadmium and lead contents. It was stated that cadmium and lead contents in arable layer and in winter wheat from both farm groups oscilated in similar ranges. Lead contents fulfilled the criteria of admissible contents in, whereas a majority of the s contained excessive quantities of cadmium. The content of both metals fulfilled the criteria their admissible contents in for consumption (to 0.20 mg Pb or Cd kg 1 d.m.). Cad- mium and lead contents in depended on acidification and cadmium content also on organic C content. Close significant correlations were found between the contents of soluble Pb and Cd forms in the s from both types of farms. Metal contents in winter wheat revealed weak relationships with properties. Lead content in from conventional farms was correlated with its contents and from organic farms with organic C content. Cadmium content in from organic farms depended on acidification. Conducted research did not confirm better quality of winter wheat originating from organic farms than that produced on conventional farms. Keywords: : organic farms, conventional farms, winter wheat,, Cd, Pb, quality assessment The problem of natural environment pollution, particularly and plant contami- nation with heavy metals has been widely discussed during last years with regard to necessity of adjustment of domestic agricultural product quality to the European Union standards. * Department of Agricultural Chemistry, Agricultural University of Krakow, Kraków, al. A. Mic- kiewicza 21, tel , fax , rrkielia@cyf-kr.edu.pl ** Department of General Plant and Soil Cultivation, Agricultural University of Krakow, Kraków, al. A. Mickiewicza 21, tel , rrklima@cyf-kr.edu.pl

2 414 Barbara Wiśniowska-Kielian and Kazimierz Klima It has been a common conviction that organic farming is more environment-friendly than the conventional system [1] and obtained products are of better quality [2]. It results from the necessarily limited use of chemical synthesis products, such as mineral fertilizers or plant protection chemicals which might supply harmful substances to the [3, 4]. It has been regulated by the Act on organic agriculture [5] adjusted to the European Union regulations. However, there are no proofs to testify a better quality of plant products from organic farms in comparison with the analogous products from traditional farms. In some opinions such differences do not actually exist [6, 7]. The number of organic farms in Poland has been growing systematically: from 27 in 1990 to 2286 in 2003; 3760 in 2004 and 7182 in So, over thrice increase in the number of organic farms in comparison with 2003 was registered by The farm area increased from ha in 2002 to ha in Arable land acreage of these farms grew from ha in 2003 to ha in 2004 and ha in 2005, which denoted over threefold growth in relation to 2003 [8, 9]. In over four- fold increase in the number of certified farms and those in the process of changing to this system of farming was registered in the Małopolska province, ie from 263 to 466 and It is connected with the system of subsidies for farms switching to this system of production. In the scale of the whole country grasslands make up about half of these farms agricultural lands, whereas in the Małopolska province they constitute over 70%. Cereals cover about 25% of the AL acreage with rye and wheat prevailing in this group [9]. The aim of the paper was to compare the quality of s and of winter wheat cultivated on organic and coventional farms in the Małopolska province area on the basis of their cadmium and lead contents and selected properties. Material and methods The object of investigations conducted in 2004 was winter wheat collected at harvest maturity stage and samples taken from the 0 15 cm layer at neighbouring organic and traditional farms, run under comparable climatic and conditions. Wheat was dried, ground, dry mineralized and the ash was dissolved in HNO 3 (1 : 2). Soil samples were dried, sifted through a plastic sieve with 1 mm mesh. Basic properties were determined with commonly used methods and trace metal concentrations af- ter extraction with 1 mol dm 3 HCl solution. Cadmium and lead were assessed in plant extracts and extracts using ICP-AES method in JY 238 Ultrace Jobin Yvon Emis- sion apparatus. Their contents in wheat were assessed according to the Minister of Health Decree [10] and following the IUNG guidelines [11]. Cd and Pb contents in were evaluated on the basis of Decree of the Ministry of the Environment on quality standards [12]. Statistical parameters were determined and relationships were assessed between cadmium and lead contents in wheat and in tested s, and with some properties using MS Office Excel 2003 calculation sheet. Significance of Pearson s correlation co- efficient was assessed on the basis of test t student function [13].

3 Comparison of Cadmium and Lead Contents in Soil and Grain of Winter Wheat Results and discussion Properties of s from both farm groups were greatly diversified. Soils from organic farms revealed lower acidification but higher content of organic carbon than the s from conventional farms. On the basis of ph KCl 10% of organic farm s were classi- fied as very acid, 8% as acid, 20% as weakly acid, 32% as neutral and 30% as alkaline, whereas 24, 20, 20, 14 and 22% traditional farm s were assigned to the respective classes [14]. Mean values of hydrolytic acidity (Hh) of s from organic and conventional farms were respectively and mmol H + kg 1 whereas organic carbon contents amount and g C kg 1 d.m., respectively. Organic farm s had lower sorption capacity but higher degree of alkaline cation saturation than conventional farm s and the values were respectively: and mmol (+) kg 1 and 85.2 and 82.9%. Acidity and degree of base cation saturation were slightly more diversified in s of organic farms, whereas ph and organic carbon content in s of traditional farms. Despite considerable diversity of farm properties within one farming system, mean values of these parameters for organic and traditional farm s from individual districts (gminas)) differed only slightly. Lead and cadmium contents in s of both farms types ranged quite widely. Soils of organic farms contained mg Pb while traditional farm s had mg Pb kg 1 d.m. (Table 1). Mean arithmetic contents were very similar whereas geometric means and medians differed slightly more and were, and mg Pb kg 1 d.m. respectively for organic farms and and mg Pb kg 1 d.m. for traditional farms. Cadmium contents in organic and conventional farm s ranged between and mg Cd kg 1 d.m., respectively (Table 1). Mean contents of cadmium were similar, but their geometric means differed more, reaching and Cd kg 1, respectively for organic and traditional farm s. Also medians differed, in their case an opposite relationship was found for both farm groups: and mg Cd kg 1. Contents of lead and cadmium in organic farm s revealed lesser variability than in conventional farms, as has been pointed by respective values of standard deviations and relative standard deviations (Table 1). Mean contents of both metals in s from individual districts did not reveal a clear- ly directed relationship but a significant correlation was found between the contents of soluble Pb and Cd forms for s from both farm groups in general (for Pb r = 0.44 and for Cd r = 0.68). Lead content in organic farm s was essentially dependant on ph KCl (r = 0.49), whereas in s from organic and conventional farms was significantly correlated with hydrolytic acidity (respectively r 0.05 = 0.33 and r = 0.49), while cadmium contents were correlated with hydrolytic acidity (r = 0.45 and r = 0.51) and organic carbon content (r 0.01 = 0.37 and r 0.05 = 0.27), and with ph KCl (r 0.05 = 0.33 and r = 0.46). In his investigations Lipiński [15] pointed to an existing relationship ip between the content of mobile forms of trace elements and properties.

4 416 Barbara Wiśniowska-Kielian and Kazimierz Klima Table 1 Cadmium and lead contents in s and of winter wheat from organic and conventional farms of Małopolska province No. Locality 1 Wola Batorska 2 Lipnica Górna Lipnica Górna Lipnica Górna Podłopień Podłopień Podłopień Tymbark Zamieście Zamieście Zamieście Zawadka Piekiełko Piekiełko Buczyna Grabina Krzeczów Krzeczów Biesiadki Biesiadki 21 Olchawa 22 Rozdziele 23 Grajów Radgoszcz Radgoszcz Radgoszcz 27 Gruszów Maniów Laskówka 30 Hubenice 31 Przybysławice District Cd Organic farms Pb [mg kg 1 ] Conventional farms Cd Pb Niepołomice Lipnica Murowana Tymbark Bochnia Gnojnik Nowy Wiśnicz Żegocina Wieliczka Radgoszcz Dąbrowa Tarnowska Szczucin Gręboszów Nowe Brzesko

5 Comparison of Cadmium and Lead Contents in Soil and Grain of Winter Wheat No Locality 32 Szczyżyc 33 Rączna Zagórzyce Michałowice 36 Sobiesęki 37 Radziszów Sąspów Sąspów 40 Maszkienice Mościce Chyszów Świerczków Lubcza Lubcza 46 Uszew Czyrna Czyrna Czyrna 50 Lubomierz District Cd Organic farms Pb [mg kg 1 ] Table 1 contd. Conventional farms Cd Pb Szczyżyc Liszki Michałowice Skała Radziszów Jerzmanowice Biadoliny Tarnów Ryglice Brzesko Krynica Nowy Targ Arithmetic mean Standard deviation Relative standard deviation [%] Soils under wheat cultivation in the area of Tymbark and Przemyśl [16] districts contained similar amounts of lead and cadmium forms soluble in 1 mol HCl dm 3 solution, however more acidified s in the Tymbark municipality contained bigger quantities of lead (6 25 mg Pb kg 1 d.m.) than less acidified s in the Przemyśl municipality ( mg Pb kg 1 d.m.). The amount of cadmium did not reveal such strong dependency on reaction and ranged respectively between and mg Cd kg 1 d.m. Natural total content of lead in s of Poland does not exceed 20 mg kg 1, on average 13.7 mg Pb kg 1 d.m. [17]. Szymona [18] found much smaller quantities of lead in s of organic and conventional farms in the Lublin province, respectively and mg Pb kg 1 d.m. According to the Decree of the Ministry of the Environment total content of studied metals in agricultural s should not exceed 200 mg Pb and 1 mg Cd kg 1 d.m. [12].

6 418 Barbara Wiśniowska-Kielian and Kazimierz Klima On the other hand, no limit numbers were definite for their forms soluble in 1 mol HCl dm 3 solution. They can be estimated on the basis of these forms share in total contents found by other authors, which is 22 99% for Pb and % for Cd [19 21]. Considering a stricter assessment criterion (lower range values) it may be estimated that total lead content in all s did not exceed 130 mg Pb kg 1 d.m., therefore it should not pose any hazard for the quality of cultivated crops. However, such danger exists in the case of cadmium because in 86% of organic farm s and 74% of conventional farm s its level may reach between > 1 and 2 mg Cd kg 1 d.m. Lead contents in wheat from organic and traditional farms ranged between and and between and mg Pb kg 1 d.m., respectively (Table 1). Despite a small difference in lead content in wheat from both types of farms, from organic farms contained on average by 10% less of this metal than from conventional farms, revealing twice or thrice greater diversification than in s, as has been pointed by dispersion measures (standard deviations and relative standard deviations) (Table 1). Geometric means amounting and mg Pb kg 1 and medians equaling and mg Pb kg 1, respectively for organic and traditional farms revealed similar dependencies. Wheat from organic farms contained between and mg Cd kg 1 and from traditional farms between 0.06 and mg Cd kg 1 d.m. (Table 1). Mean Cd content in from both types of farms was medium and revealed similar variability, slightly smaller than in case of cadmium concentrations in. Even more similar were values of geometric means, which were and mg Cd kg 1 and values of medians, which were and mg Cd kg 1 d.m., respectively for organic and conventional farms. Mean contents of Cd and Pb in winter wheat from individual districts differed slightly and no unambiguous tendencies in this respect were found, despite a clear relationships between the contents of their soluble forms in s of both farm groups. Lead content in wheat from traditional farms revealed a weak correlation with its content in (r 0.05 = 0.29) and in organic farms with organic carbon contents (r 0.05 = 0.28). Cadmium content in wheat from organic farms was correlated with hydrolytic acidity (r 0.01 = 0.38) and ph (r 0.01 = 0.40). It confirms the observations that with increasing ph cadmium sorption weakens in result of its being dislodged from sorption complex by alkaline cations [17]. The other properties had no significant effect on metal accumulation in. It confirms other authors observations, who generally did not find significant relationships or demonstrated weak dependencies between trace element content in / solution and their contents in wheat [22, 23]. Information about apparent influence of heavy metals in on their content in plants usually come from pot experiments [24] or from areas strongly polluted with these elements [25]. Winter wheat in Poland contains between 0.2 and 0.8 mg Pb kg 1, on ave rage 0.32 mg Pb kg 1 and between 0.05 and 0.07 mg Cd kg 1 d.m., on average 0.05 mg kg 1 d.m. [17]. Mean contents of lead in wheat from both farm groups were over 5 times lower than these or values stated by Kucharzewski and Dębowski [26], but twice or thrice lower than observed in the area of Tymbark and Przemyśl districts. On

7 Comparison of Cadmium and Lead Contents in Soil and Grain of Winter Wheat the other hand, mean contents of cadmium in the tested were twice higher, like in the Przemyśl district but by half lower than in from the Tymbark district [16]. High quality food products should contain the least possible amounts of harmful substances, among others heavy metals. Permissible content of lead and cadmium in cereal s for consumption is 1.0 mg Pb kg 1 and 0.15 mg Cd kg 1 [11]. According to the Decree of the Minister of Health [10] lead contents in for consumption should not exceed 0.20 mg kg 1 d.m. whereas cadmium content 0.20 mg kg 1 d.m. (before joining the EU it was 0.10 mg Cd kg 1 d.m.). Therefore, the tested winter wheat from both farm groups meets the stricter requirements of the Decree [10] for lead, whereas respectively 46 and 48% of samples from organic and conventional farms contained over 0.10 mg Cd kg 1 but less than 0.20 mg Cd kg 1 d.m. Relatively low content of trace metals in may result from plant defensive ca- pacities against excessive translocation of harmful substances to the aboveground parts, particularly generative ones through their fixation in the form of phytochelatines in roots and vegetative organs [27 29]. Obtained results do not allow for an unambiguous conclusion that organic system of production ensures better health quality of obtained plant material than the traditional system because of small differences in trace element content in compared. Jorhem and Slanina [30] obtained similar results in their two-year studies on heavy metals in wheat and rye s from farms in Sweden using organic and conventional cultivation methods. It may be said that the way of cultivation does not markedly influence trace metal contents in field crops. A lack of such dependence may be caused by other factors. Organic agriculture guarantees that no means whose use has been prohibited in this system of farming were applied, but does not guarantee that the products are free from impurities from, water or air [31]. In the Małopolska province heavy metal pollution does not pose any grave hazard and there are excellent conditions for organic production [32]. High contents of zinc, lead and cadmium in are mainly connected with exploitation and processing of these metals [32], still in submontane areas s, which developed from Carpathian flysch may reveal naturally elevated contents of heavy metals or show weak pollution with them [33], therefore there is a possibility of excessive trace metals acquisition by crops. Conclusions 1. Content of lead and cadmium in the surface and winter wheat from organic and conventional farms ranged similarly. 2. Lead contents met the criteria of permissible level in, whereas a majority of s contained excessive amounts of cadmium. 3. Contents of both metals fulfilled the criteria of permissible amounts in for consumption. 4. Cadmium and lead contents in depended on acidification, moreover cadmium content depended on organic C content. Significant correlations were found between the contents of soluble Pb and Cd forms in s from both farm groups in general.

8 420 Barbara Wiśniowska-Kielian and Kazimierz Klima 5. Both metals content in winter wheat revealed weak relationship with properties. Lead content in from conventional farms was correlated with its content in, while from organic farms with organic carbon content. Cadmium contents in from organic farms depended on acidification. 6. The conducted investigations did not confirm a better quality of wheat from organic farms than produced on conventional ones. References [1] Trewavas A.: Nature, 2001, 410,, [2] Worthington V.: J. Alt. Complem. Med., 2001, 7,, [3] Beharrel B. and MacFie J.H.: Brit. Food J., 1991, 93,, [4] Hansen B., Alroe H.F. and Kristensen E.S.: Agric. Ecosys. Environ., 2001, 83,, [5] Ustawa o rolnictwie ekologicznym z dnia 20 kwietnia 2004 r. Dz.U. 2004, Nr 93, poz. 898, [6] Horubała A.: Przem. Spoż., 1993, 6,, [7] Romanowska M.: Skład jakościowy roślin uprawnych w gospodarstwach ekologicznych. Praca doktorska (maszynopis), Akad. Roln. Wrocław 2004, 155 p. [8] GUS Ochrona Środowiska Informacje i opracowania statystyczne. Warszawa 2005, 540 ss. [9] Grzesiak M. and Domańska W. (Eds.): Ochrona Środowiska Informacje i opracowania statystyczne. GUS, Warszawa 2006, 522 p. [10] Rozporządzenie Ministra Zdrowia z dnia 13 stycznia 2003 r. w sprawie maksymalnych poziomów zanie - czyszczeń chemicznych i biologicznych, które mogą znajdować się w żywności, składnikach żywnoś- ciowych, dozwolonych substancjach dodatkowych, substancjach pomagających w przetwarzaniu albo na powierzchni żywności. Dz. U. 2003, Nr 37, poz. 326, [11] Kabata-Pendias A., Motowicka-Terelak T., Piotrowska M., Terelak H. and Witek T.: Ocena stopnia zanieczyszczenia gleb metalami ciężkimi i siarką. Ramowe wytyczne dla rolnictwa. Wyd. IUNG Puławy 1993, Seria P(53), 20 p. [12] Rozporządzenie Ministra Środowiska z dnia 9 września 2002 r. w sprawie standardów jakości gleby oraz standardów jakości ziemi. Dz. U. 2002, Nr 165, poz. 1359, [13] Trętowski J. and Wójcik A.R.: Metodyka doświadczeń rolniczych. Wyd. WSR-P Siedlce 1991, 538 p. [14] Obojski J. and Strączyński S.: Odczyn i zasobność gleb Polski w makro i mikroelementy. IUNG, Puławy 1995, 40 p. [15] Lipiński W.: Oddziaływanie niektórych właściwości gleby na zawartość metali ciężkich w ziarnie pszenicy, żyta oraz bulwach ziemniaka. Rozpr. Nauk. Akad. Roln. Lublin 2001, 249,, 78 p. [16] Wiśniowska-Kielian B.: Ecol. Chem. Eng.., 2003, 10(9), [17] Kabata-Pendias A. and Pendias H.: Biogeochemia pierwiastków śladowych. Wyd. Nauk. PWN, Warszawa 1999, 398 p. [18] Szymona J.: Ecol. Chem. Eng.., 2005, 12(3), [19] Khdri Y., Karczewska A. and Szerszeń L.: Mat. VII Symp. Mikroelementy w rolnictwie, 1992, [20] Karczewska A.: Zesz. Probl. Post. Nauk Rol., 1998, 456,, [21] Jackowska I. and Bojanowska M.: Badania nad formami i rozpuszczalnością metali ciężkich w glebie lessowej. Roczn. Glebozn., 2000, LI(1/2), [22] Kabata-Pendias A.: Roczn. Glebozn., 1975, XXVI,, [23] Właśniewski S.: Zawartość i fitoprzyswajalność wybranych metali ciężkich w glebach regionu Płaskowyżu Kolbuszowskiego i Pogórza Rzeszowskiego. Praca doktorska (maszynopis), Akad. Roln. w Kra- kowie, Kraków 1998, 130 p. [24] Kabata-Pendias A. and Wiącek K.: Roczn. Glebozn., 1985, XXXVI(4), [25] Kabata-Pendias A. and Tarłowski P.: Roczn. Glebozn., 1981, XXXII(3), [26] Kucharzewski A. and Dębowski M.: Zesz. Probl. Post. Nauk Rol., 1996, 434,, [27] Kinnersley A.M.: Plant Growth Regul., 1993, 12(3), [28] Tukendorf A.: Post. Biochem, 1993, 39(1), [29] Van Steveninck R.F.M., Babare A., Fernando D.R. and Van Steveninck M.E.: Plant Soil, 1994, 167(1), [30] Jorhem L. and Slanina P.: J. Sci. Food Agric., 2000, 80,,

9 Comparison of Cadmium and Lead Contents in Soil and Grain of Winter Wheat [31] Sołtysiak U. (red): [w:] Ekologiczne i integrowane rolnictwo w Polsce. Raport 1995, Wyd. Fun- dacja Rozwój SGGW, Warszawa [32] Tokarz M. and Turzański P.K.: Ocena stanu zanieczyszczenia gleb województwa małopolskiego metalami ciężkimi i siarką. Bibl. Monit. Środow., PIOŚ Kraków 1999, 117 p. [33] Terelak H., Motowicka-Terelak T., Słuczyńska T. and Pietruch Cz.: Pierwiastki śladowe (Cd, Cu, Ni, Pb, Zn) w glebach użytków rolnych Polski. Bibl. Monit. Środow., PIOŚ Warszawa 2000, 69 p. PORÓWNANIE ZAWARTOŚCI KADMU I OŁOWIU W GLEBIE I ZIARNIE PSZENICY OZIMEJ Z GOSPODARSTW EKOLOGICZNYCH I KONWENCJONALNYCH Streszczenie z e e Porównano jakość gleb i ziarna pszenicy ozimej uprawianej w gospodarstwach ekologicznych i konwencjonalnych z terenu województwa małopolskiego na podstawie zawartości kadmu i ołowiu. Zawartość ołowiu i kadmu w warstwie ornej gleb oraz ziarnie pszenicy ozimej z obydwu grup gospodarstw mieściła się w podobnych zakresach. Zawartość ołowiu spełniała kryteria dopuszczalnych zawartości w glebie, natomiast większość gleb zawierała nadmierne ilości kadmu. Zawartość obydwu metali spełnia- ła kryteria dopuszczalnych zawartości w ziarnie przeznaczonym na cele konsumpcyjne (do 0,20 mg Pb lub Cd kg 1 s.m.). Zawartość kadmu i ołowiu w glebie zależała od zakwaszenia, a kadmu ponadto od zawarto- ści C organicznego. Stwierdzono istotne korelacje między zawartościami rozpuszczalnych form Pb i Cd dla ogółu gleb z obydwu grup gospodarstw. Zawartość metali w ziarnie pszenicy wykazywała słabe zależności z właściwościami gleby. Zawartość ołowiu w ziarnie z gospodarstw konwencjonalnych była skorelowana z jego zawartością w glebie, a z gospodarstw ekologicznych z zawartością węgla organicznego. Zawartość kadmu w ziarnie z gospodarstw ekologicznych zależała od zakwaszenia gleby. Przeprowadzone badania nie potwierdziły lepszej jakości ziarna pszenicy pochodzącego z gospodarstw ekologicznych niż wyprodukowanego w gospodarstwach konwencjonalnym. Słowa kluczowe: : gospodarstwa ekologiczne, gospodarstwa konwencjonalne, ziarno pszenicy ozimej, gleba, Cd, Pb, ocena jakości