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Investigations were carried out by the means of leaching in laboratory columns. The significant correlation between pH-value of soil solution and activity of A1 wax found. Potassium fertilizers (KCl, K₂SO₄) and gypsum increased the activity of Al and acidified the soil solution. However, the intensity of decreasing of pH-value was markedly greater by the supplying of potassium chloride than of potassium sulphate. The addition of straw markedly buffered changes of pH, caused by the application of salts. The activities of straw were most effectively in the acid soil and more efficient than liming. Straw reduced the content of A1 in the soil solution too, but only in the interaction with sulphates (K₂SO₄, CaSO₄ · 2H₂O). In case of chloride-treatments, the addition of straw influenced on the increment of Al-activity. Results of investigations suggest that by using buffering system as organic matter and sulphates it is possible to prevent negatives effects of Al-influences on soil medium.
Role of some soil and fertilizer factors at the uptake of heavy metals by plants was characterized in the paper. The following factors were considered: kind and contents of heavy metals in soil, soil pH-value and liming, humus content in soil and applied organic matter fertilization, content of clay minerals in soil and application of different adsorbents, content of Al-, Fe-, Mn-oxides in soil and their application, soil redox potential, nitrogen and phosphorus fertilization, and content of salts in soil solution. It was highlighted, that some of these factors are really important in fertilization technology. They may be used to reduce the bioavailability of heavy metals to plant. To these fertilizer factors the liming, application of organic matter at high humification level, application of nitrogen fertilizers, which increase the soil pH-value (N-NO₃), and application of potassium fertilizers in form of sulphate are to be included.
Fertilization of plants with ammonium nitrogen form leads to the soil acidification. Leguminous plants with higher requirements of basic cations, acidify soil quicker than other plants such as, e.g., of the Gramineae family. These relationships were confirmed in the pot experiments with broad bean and maize. In the present experiment the effect of fertilization with different nitrogen forms on yield and pH value of soil was investigated. It has been found that the application of ammonium sulphate with a nitrification inhibitor results in a significant increase of the pH value of soil under broad bean. It can be presumed that this effect would be caused by physiologically basic reaction of ammonium sulphate due to the blockade of nitrification and to a more intensive utilization of sulphur ions by broad bean as compared to ammonium ions.
Changes in the mobility of Zn, Cd, Pb and Cu in medium sand soil depending on forms of salts: K₂SO₄ + MgSO₄ or KC1 + MgCl₂ were studied. Those salts were applied at varying soil pH-value (5,4; 6,2; 7,0). Studies were carried out in the leaching experiments using laboratory columns. Heavy metals were leached by simulation 600 mm of rainfall, over a 6 month periods. Leachates were collected and analysed every 200 mm portion of simulated rainfall. Concentrations of Zn, Cd, Pb and Cu in leachates showed that significant increment in the mobility of tested heavy metals took place during the first 200 mm portion of rainfall simulation. It was confirmed that applied salts caused increasing in the leachability of Cd about 35-100 times, Zn about 45-50 times, Pb about 5-10 times and Cu about 3-5 times, comparing to unfertilized soil at pH-value 5,4. Those ranges in the mobilization of heavy metals were significant lower in case of using sulphate salts than chloride salts. In case of Cd, Pb and Cu, the effect of sulphate treatments at lower pH-value (5,4) was compared to chloride-treated soil at higher pH-value (6,2). On the base of the electrical conductivity of leachates, it was concluded that changes in the mobility of heavy metals by the salts application were determinated through different dynamics of certain bases cations (particularly Ca²⁺ ) between soil solid and soil solution. The lower dynamics of Ca²⁺ ions, and consequently decreasing in heavy metals desorption by K₂SO₄ application was influenced through CaSCO₄-precipitation in soil solution.
Badania prowadzono metodą doświadczeń laboratoryjnych, wazonowych i polowych. W doświadczeniu laboratoryjnym badano, przy użyciu kolumn glebowych (6 x 40 cm), mobilność Zn, Cd, Pb i Cu w glebie w zależności od dodatku słomy jęczmiennej oraz zróżnicowanego pH gleby (5,4: 6,2; 7,0). W doświadczeniu wazonowym i polowym badano natomiast pobieranie Zn, Cd i Pb przez rośliny uprawne w zależności od zastosowania trzech rodzajów materii organicznej: słomy, torfu i węgla brunatnego. Badania prowadzono na glebie silnie zanieczyszczonej Zn, Cd i Pb oraz o podwyższonej zawartości tych pierwiastków. Roślinami testowymi w doświadczeniu wazonowym i polowym były: burak ćwikłowy, sałata, żyto, jęczmień jary, ziemniak oraz pszenżyto jare. W doświadczeniu modelowym stwierdzono, że dodatek słomy zmniejszał ruchliwość cynku i kadmu w glebie kwaśnej, natomiast zwiększał mobilność ołowiu i miedzi w glebie kwaśnej i lekko kwaśnej. Dodatek słomy do gleby zwiększał również bioakumulację Pb w doświadczeniu wazonowym. Spośród badanych trzech rodzajów substancji organicznej, węgiel brunatny wykazywał najlepszą skuteczność w ograniczaniu pobierania Zn, Cd i Pb przez rośliny.
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