Zachowanie fosforu w glebie jest istotnym zagadnieniem zarówno ze względów produkcyjnych, jak i środowiskowych. Zminimalizowanie presji na środowisko ze strony rolnictwa wymaga między innymi rozpoznania czynników decydujących o procesach sorpcji biogenów w glebie. Celem pracy była analiza zdolności retencyjnych oraz parametrów sorpcji fosforu w glebach płowych i czarnych ziemiach w układzie katenalnym moreny dennej. Korzystając z analizy regresji wstecznej opracowano równania umożliwiające oszacowanie parametrów sorpcji Langmuira w oparciu o podstawowe właściwości gleby. Wykazano, że parametr a (maksymalną ilość fosforu, jaką może zatrzymać faza stała gleby) oszacować można w oparciu o zawartość węgla organicznego, amorficznych tlenków glinu, wapnia wymiennego i fosforu przyswajalnego. Natomiast parametr sorpcji Langmuira „b” kształtowany był przez zawartość frakcji iłowej, tlenków glinu i żelaza oraz amorficznych form żelaza.
Three oxide-bearing amendments – steel shots, spodic horizon and Portland cement – were evaluated by sequential extraction procedure and leaching test to determine their ability to reduce heavy metal mobility in metal-spiked soil. The incubation experiment was conducted on surface soil horizon that was contaminated with Cu, Pb and Zn as Cu(NO3)2⋅6H2O, Pb(NO3)2, and Zn(NO3)2⋅6 H2O. Each metal was introduced at the rate of 5,000 mg·kg-1. As soil pH strongly influences heavy metal mobility, especially Zn, in this experiment two levels of soil reaction were tested – pH 4 and pH 6. The rise of pH up to pH 6 was undertaken by the addition of calcium carbonate to contaminated soil after 4 weeks of pre-incubation. Next, oxide-bearing amendments were added at the rate: 0, 1 and 3% (on dry weight basis) and the incubation proceeded further for 12 weeks. When the incubation process was finished leaching test was started. During leaching test, additional pH of leachate was analyzed. Result from leaching test showed that metal mobility changed with soil reaction. When reaction of soil solution was below pH 4.6, metal leaching decreased for Zn < Cu < Pb, but between pH 4.6 and the 8.2 the sequence was Zn < Pb < Cu. Above pH 8.2 of soil solution metals showed completely different mobility pattern, the quantity of metals washed out in the order Cu < Pb < Zn. Among tested amendments, the highest efficiency of stabilization process was obtained with cement, independently of soil pH and the dose of the stabilizer. In the case of steel shot, immobilization of trace elements depended on pH and the dose of amendment, higher reduction of metal mobility was obtained in the soil with 3% of stabilizer dose in CaCO3-treated soils.
W pracy przedstawiono wyniki sezonowych zmian stężeń ortofosforanów (V) w zlewni Jeziora Gorzuchowskiego w latach hydrologicznych 2005–2006. W celu określenia potencjalnego ryzyka transportu fosforanów ze źródeł rolniczych opracowano numeryczny model terenu, mapę zagrożenia erozją wodną powierzchniową oraz opisano i zanalizowano pokrywę glebową zlewni. Próbki wód do badań pobierano raz w miesiącu w dwóch punktach pomiarowo-kontrolnych na rzece Małej Wełnie, powyżej i poniżej Jeziora Gorzuchowskiego, oraz z samego jeziora. Określano temperaturę, pH oraz stężenia O2, Ca2+, Mg2+, Cl-, SO4 2-, PO4 3- i mineralnych form azotu. Analizę specjacyjną przeprowadzono za pomocą programu Visual Minteq, bazującego na najnowszych stałych reakcji chemicznych. Na podstawie wielkości stężeń fosforanów (V) stan ekologiczny wód rzeki Małej Wełny (ppk Kłecko i Zakrzewo) określono jako poniżej dobrego. Dominującą formą fosforanów (V) w wodach zlewni był aniony HPO4 2-, co związane było z odczynem badanych wód. Warunki środowiska panujące w okresie badawczym, z wyjątkiem maja i czerwca, sprzyjały wytrącaniu hydroksyapatytu i akumulacji fosforu w osadach dennych.
Our paper presents the results of determining temporal variability in the water table depth in topohydrosequence of Retisols/Luvisols and Phaeozems/Gleysols. Assessing temporal variability in the water table was done using geostatistical and statistical methods. The mean annual water table depth in soils occupying higher locations in the relief were determined by precipitation in the given and previous years, but in soils of footslope only by precipitation in a given year. Water table fluctuations were characterized by a clearly visible temporal structure and low values of random variability. The range of time correlation of water table was dependent on the relief and was shorter in soils located in lower parts of the topohydrosequence and longer in wells in the higher part. The contribution of the nugget effect in variance was also dependent on the location of wells on the slope. The obtained values of the fractal dimension (D) show a distinct relationship between D and the location of soil in the topohydrosequence. The values of multivariate analysis indicated that the statistical and geostatistical parameters applied to assess temporal variability of water table depth were dependent on the soil (well) location in the relief.
Most of the processes occurring in soil are catalysed by enzymes. As a result of their sensitivity towards heavy metals, enzymes in contaminated soils are usually less active. The purpose of this paper was to assess the influence of bioavailable forms of Cd, Cu, Pb and Zn on the activity of dehydrogenases, urease, acid and alkaline phosphatase, and to compare the results obtained from naturally and artificially contaminated soils. A pot experiment was carried out on two loamy sand soils, naturally and artificially contaminated with Cd, Cu, Pb and Zn. The total content of heavy metals classified these soils as very heavily contaminated with Cu, heavily contaminated with Pb and contaminated with Cd and Zn, all according to the IUNG system (1995). One of the following organic materials: swine manure or triticale straw, was added to the soil batches. The experiment was carried out in three replications, in two pH ranges: slightly acid and acid. Soil samples for analyses were taken after 14, 28, 165 and 450 days of incubation. The results of the experiment showed that the activity of soil enzymes depended on the content of bioavailable heavy metals; the total concentration of trace elements and H+ were less important. However, considerable differences were found in enzyme activity between naturally and artificially contaminated soils. This indicates that results obtained from other research conducted on freshly contaminated soils cannot be easily transferred to field conditions. The analysed enzymes responded differently to the concentration of bioavailable forms of heavy metals. Alkaline phosphatase was the least tolerant to bioavailable forms of heavy metals, unlike urease, which was the most tolerant soil enzyme. A similar pattern of sensitivity toward trace elements, which could be ordered as Zn > Cd > Cu > Pb, was noticed for dehydrogenases, acid and alkaline phosphatases. Urease was found to be more tolerant to Zn.