Joint International Conference on Long-term Experiments ...

agrochemicals as fertilizers and pesticides, the probability of contamination or
accumulation was considerable.
The group of organochlorines are widely used pesticides and are important in the
aspects of food safety (Kan and Meijer, 2007). The peak of their application was in the
’50ies and ‘60ies. Many of them were banned later in the most countries in Europe and
North America, but in developing countries large amounts have been applied in the
‘90ies (Kannan et al., 1997) and are still in use nowadays in several countries. The
information about organochlorine contamination is mostly limited to DDTs and lindane,
but it is easy to accept that other dangerous pesticide remains are still in our soils
(Shegunova, 2007). It may be also proved by the fact that both Hungarian and European
Union soil and water quality standards contain target and intervention values for DDTs,
drins as aldrin and endrin, and HCH and HCB (Oldal et al., 2006). Besides, earlier
studies on Hungarian surface water monitoring reports that 8 out of the examined 21
pesticide residues exceeded the 0,1 μg/l limit concentration required by EU directives
(Kárpáti et al., 1998).
From the aspect of food safety another important soil property is its element
content, primarily the heavy metal content. Excessive amounts of metals originated
from agricultural or industrial production often cause human actions (Biehl and Buck,
1987). It is important to monitor the cadmium, lead, mercury and arsenic contents in
both soils and the products from different locations, although the latter is not heavy
metal by original definition, but in several cases it poses similar risk. Besides limit
values in different national and international standards, the Ministry of Agriculture in
Netherlands published the so-called LAC values, which define the limit values that are
“the lowest level in soil that, when exceeded, may give rise to the emergence of
negative impacts on the yield and the quality of agricultural products, and with the
health of human beings and animals” (Brus et al., 2005). This recommendation gives
different limit values according to both soil type (as sand or clay) and grown plant (as
grassland, arable land with flowers or arable land with food for human consumption). In
Hungary the current limits are declared in 10/2000. (VI.2.) KöM-EüM-FVM-KHVM
ministry order in which the background (A) levels, contamination limit (B) levels and
environmental remediation contamination limit (D) levels are determined. Naturally, the
aim of production often raises a claim to decrease the maximum heavy metal level in
soils, e.g. in the case of producing drug or medicine raw materials.
In our case study we had an opportunity to evaluate and estimate three kinds of
cropping sites in the aspects of food safety; an intensively used (for wheat and maize
production), an extensively used (for meadow) and one used in bio production.
MATERIALS AND METHODS
Soil samples: Examined sites were the followings: two winter wheat production sites
near to Szentes and Sárrétudvari, two maize production sites by Nádudvar and
Hajdúböszörmény, a meadow near to Bakonszeg and a bio production area at the
Látókép Experimental Station of University of Debrecen, Centre of Agricultural
Sciences. Site samplings were made in the summer of 2005 from the upper 20
centimetres of soil and from the 100-130 cm depth and 200-235 depth as well. In 2006
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