The effects of
fertilization, irrigation and crop rotation on the major soil parameters and
microbiological soil properties were studied at Debrecen-Látókép in the 16th
and 17th years of the fertilization experiment on calcareous
chernozem soil. The results can be summarized as follows: In the examination period the moisture
content of the experimental soil increased by 2-3% due to irrigation. With increasing fertilizer doses, the pH
value of soils reduced both in aqueous and
KCl suspension, but it did
not change considerably at medium and high fertilizer doses. The hydrolytic
acidity increased with decreasing pH values. The nitrate-N, AL-soluble phosphorus and
potassium contents increased gradually with increasing fertilizer doses. Among the soil microbial parameters, the
total number of germs increased slightly, while the amount of nitrifying
bacteria was significantly higher due to fertilization. As a result of
a significant increase was detected in the phosphatase and urease activityin
both crop rotations and irrigation treatments. The activity of saccharase and
catalase was reduced at medium and high fertilizer doses. In addition to
changing the moisture content of soils irrigationincreased the total
number of germs and the amount of nitrifying and cellulose decomposing
bacteria. Irrigation provided more favourable conditions for CO
increasing the microbial biomass C content and for the functioning of
phosphatase and urease enzymes.
In triculture the number of
nitrogen-fixing and cellulose decomposing bacteria was higher than in
monoculture, especially in the case of medium and high fertilizer doses. The
activity of phosphatase, saccharase and urease enzymes was significantly higher
in triculture than in monoculture.
Dirt level in sugar cane consignments delivered to the factory is dependent on soil type, in association with harvesting system and weather conditions. Efforts for reducing soil in harvested cane have been made by sugar cane millers, especially improving the washing system installed before crushing. Instrumental neutron activation analysis has shown its potential for assessing dirt reductions in the washed material. Knowledge of elemental concentrations in the different soil fractions highlights the reliability of such measurements especially when taking into account the soil characteristics.
Authors:Péter Sipos, Tibor Németh, Chung Choi, Zoltán Szalai and Réka Balázs
Knowledge of the distribution and sorption characteristics of trace metals in soils is essential because of their importance both from agricultural and environmental point of view. In this paper, an overview will be provided on the relationship between the behavior and sorption properties of Cu and Pb as well as major soil characteristics, based on the results obtained by several independent research projects carried out on this field at the Institute for Geological and Geochemical Research over the last 15 years. These projects were accomplished using methods with different approaches, e.g. studying metal characteristics by total metal content, selective chemical extractions and batch sorption experiments.Our results show that both metals can be found in soils, primarily in the form of phases highly resistant to weathering. However, if they are mobilized, they are easily and strongly immobilized by soils rich in organic matter, with higher affinity for Cu than for Pb. In acid soils, on the other hand, the leaching of Cu is expected to be higher from such horizons when compared to Pb, especially when iron oxides, which immobilize Pb preferentially, are also present in these horizons. In mineral horizons the close association of Pb and iron oxides can be still expected, whereas Cu prefers to be bound both by clay minerals and iron oxides. In alkaline soils, however, precipitation of both metals as carbonates is a general feature. Our results obtained through different approaches presented in this paper were found to be effectively complementary to each other, providing a much deeper insight into soil-metal interaction than when they are used independently.
Authors:János Jóvér, Elza Kovács, Péter Riczu, János Tamás and Lajos Blaskó
One option for adaptation to climate change is to grow a wider variety of plant species. Sorghum (Sorghum bicolor (L.) Moench) is known to tolerate unfavourable environmental conditions, so it may be feasible to grow it on areas with extreme conditions to replace other species such as maize. Nowadays, spatial decision supporting systems primarily support the crop production process rather than crop structure adjustment. In this study, potential sorghum production sites in the Great Hungarian Plain were selected based on soil characteristics including genetic soil type, parent material, physical soil type, clay composition, water management, pH, organic matter content, topsoil thickness and fertility, as well as climatic data, particularly precipitation. For all the parameters the aim was to find the extreme values at which sorghum, which is less sensitive than maize, may still give an acceptable yield. By combining map layers of soil characteristics, it could be concluded that although the soil is suitable for sorghum on 40.46% of the Great Hungarian Plain, maize is generally a better choice economically. On the other hand, the soil conditions on 0.65% of the land are still suitable for sorghum but unfavourable for maize. As regards the precipitation demand of sorghum, May is the critical period; on 698,968 ha the precipitation required for germination was only recorded once in the period 1991-2010, so these areas cannot be considererd for sorghum. As a consequence, in an alternative crop rotation system sorghum could be competitive with maize, but both the soil and climate conditions and the demands of the crop need to be assessed. The lack of precipitation in critical phenophases significantly decreases the area where maize can survive. Sorghum, however, may produce an acceptable yield, as it is a drought-resistant species.
Authors:Petya Kovacheva, Desislava Yovkova, Boian Todorov and Rumyana Djingova
Extreme changes of environmental conditions can alter the soil properties and influence the migration ability and bioavailability of pollutants. Elucidation of the effects of the extreme weather conditions, such as sharp temperature change, drought and floods, on the fractionation of radionuclides in different soil types is especially important for adequate risk assessment after radioactive contamination. The effects of short-term and prolonged freezing and soil drought on the geochemical fractionation of americium in two soil types (Fluvisol and Cambisol, classified according to the World Reference Base for Soil Resources/FAO) from Bulgaria were studied. The changes of the physico-chemical forms of 241Am after storage under different conditions were determined by the sequential extraction procedure and gamma-spectrometric measurements. The impact of the sharp temperature decrease and drought on the association of the radionuclide with the various soil phases was considered in terms of the soil characteristics. The results showed that the risk of increased mobility and bioavailability of americium in the loamy-sand soil with acidic pH and very low cation exchange capacity (CEC) exists under the examined extreme environmental conditions. The soil with sand-loam texture tended to immobilize americium after freeze and drought storage.
Authors:N. Filipović-Vinceković, D. Barišić, N. Mašić and S. Lulić
The distribution of137Cs through soil layers has been investigated by field sampling. The investigation deals with137Cs concentration found after the Chernobyl accident. The relationship between important soil characteristics, total precipitation and cesium distribution are analyzed. Cesium is strongly sorbed in the top soil layer and its migration downward is limited. Measurements performed over a 3-year period revealed that approximately 20–38 per cent of total137Cs is located in the upper soil layer.
Authors:M. Koyama, M. Shirakawa, J. Takada, Y. Katayama and T. Matsubara
More than 2000 samales of land plant leaves, mostly of tree, have been analyzed by neutron activation analysis in order to find out macroscopic relations between distributions of chemical elements in plants and soil characteristics. The distributions of the elements in plants were also examined from the view point of botanical taxonomy or phylogeny. New species which accumulate Co, rare earths, Ba, Ra, heavy halogens and some other elements have been found. Capability or potentiality for accumulating elements could be related to higher ranks of taxonomy, that is, genus or family. The nature of soil is also found to have profound effects on the extent of accumulation of elements in plants.
Depth profiles of the long-lived radionuclides, 137Cs, 90Sr, Pu isotopes and 241Am were examined in undisturbed sandy, peaty and Podsol soils in the Chernobyl 30 km exclusion zone sampled around 10 years after the accident. Two Podsol soils, which have different radioactive deposition characteristics, have also been examined. Activity ratios of 239,240Pu/137Cs, 90Sr/137Cs, and 241Am/137Cs in the 0-1 cm layer of the two Podsol soils differed very much. Speciation of the radionuclides by sequential selective extraction was examined in the soils. Depth profiles of the soils have been analyzed according to the speciation results and soil characteristics.
The national soil-mapping project initiated and led by Kreybig was unique being a national, large-scale survey based on field and laboratory soil analysis and in the meantime serving practical purposes. By its completion, in the early 1950s, Hungary was the first country in the world having such detailed soil information for the whole country. The Kreybig maps are still timely, because the temporal changes in the mapped soil characteristics are not significant. The GIS adaptation of information originating from this survey is under construction, but there is more utilizable information originating from this survey, than it was published in the map series and in reports, and what is provided by simply archiving them digitally. Compilation of the Digital Kreybig Soil Information System as a national spatial soil information system involves both its integration within appropriate spatial data infrastructure and updating with efficient field correlation, which make an inherent refinement and upgrading of the system possible. The field-based updating of DKSIS using field GIS technology by the implication of recent data collected at revisited sites makes the comparison of archived and newly surveyed soil state possible. This, in one hand, should be recorded in the database by updating it. On the other hand, trends can be identified in soil characteristics, thus processes can be realized and/or forecasted. Based on the upgraded database we produce soil maps (i) displaying recent state of soils (ii) with increased accuracy and (iii) according to the soil-mapping concept elaborated by Kreybig et al.