ACTA AGRONOMICA VOLUME 43. (A MTA AGRÁRTUDOMÁNYI KÖZLEMÉNYEI, 1994-1995)

1994-1995 / 1-2. szám - SOIL SCIENCE AND AGROCHEMISTRY - I. KÁDÁR: Effect of heavy metal loadon soil and crop

4 I. KÁDÁR human organism is not evolutionally prepared for adapting itself to the chemical load of the environment. The accumulating elements are relatively stable and may cause irrever­sible changes. According to literary data (Purves, 1985; Fergusson, 1991; Kádár, 1991) in the blood, urine, hair, tissues of the urban population the concentrations of lead (Pb) and cadmium (Cd) have increased by orders of magnitude. The investigations were aimed at finding an answer to the question: to what extent can the major microelement contaminants accumulate in the nutrient chain? We attempt­ed to follow the movements of elements in the soil-plant-animal system. The points studied experimentally were: 1. The behaviour of the elements in the soil (fixation, availability, leaching, volatilization, transformation, etc.). 2. Their effect on the life of soil (biological activity, macro- and microorganisms in the soil, etc.). 3. Absorption of elements by plant roots, and their transport within the plant (their accumulation in shoots, leaves, stalks, grains). 4. Effect of elements on the quantity and quality of yield, on disease resistance and weediness. 5. Their effect on animals. The plant material obtained from the field experiment is used for feeding experiments at the Department for Animal Feeding of the University of Veterinary Science. The materials of the experiments (soil, plant and animal) were analysed by the ICP laboratory in the Agrochemical and Plant Nutrition Section of the TAKE Our inves­tigations are supported by the Ministry of Environment Protection and Regional Development. The small-plot loading experiment was set up in spring 1991 in Mezőföld (region in Transdanubia) at the Nagyhörcsök Experiment Station of the Institute. From the first year results, no far-reaching conclusions can be drawn, and the emphasis was laid on formulating the problem. Materials and methods The soil for the experiment was calcareous loamy chemozem formed on loess containing about 3% humus and 5% CaCOj in the ploughed layer. To ensure a satisfactory macroelement supply 100 kg/ha N, P2 05 and K20 were given yearly as basic fertilization in the whole experiment. The 13 selected microelements were followed up on 4 levels of loading (in 52 treatments) and in 2 replications. The size of plot was 21 m", and the experiment was arranged in split-plot design. In the first year, maize was sown with the usual cultural practices employed. Harvesting was carried out by means of a plot combine. The treatments of the experiment and the forms of the compounds applied are contained in Table 1. During the vegetation period, soil samples were taken twice. The average samples each represent 20 subsamples taken from the ploughed layer. The plant stand was also sampled several times, with 20 plants per plot taken from the net area: root + shoot at 4-6-leaf stage, leaves below the cob at the time of flowering, stalk and grains on harvesting. The preparation and the ICP analysis of the samples were made in the usual way. From the plant the total element content was determined after exposure in teflon bomb using cc HN03 + H202, while, in the soil samples, the available or mobile NH4acetate + EDTA soluble element content was measured after Lakanen and Erviö (1971). Acta Agronomic a Hungarica 43, 1994-95

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