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Most of the tuff cones in the North Tanzanian region have not been studied in depth. Therefore, the range of known rock types is limited, and the relationships between these cones are unknown. Our study focused on the Black Belly tuff cone located close to Oldoinyo Lengai. Petrographically, the studied Black Belly samples are alkaline basalts with microcrystalline groundmass and phenocrysts. The groundmass consists of plagioclase, clinopyroxene, Ti-magnetite, apatite, and the phenocrysts are predominantly clinopyroxene, altered (to calcite and serpentinite) olivine, and carbonate minerals. While Oldoinyo Lengai and Black Belly rocks are not similar or directly related, the mineralogy and mineral chemistry of the studied Black Belly samples are similar to those representing the Crater Highlands' volcanoes. Based on their compositions, the Black Belly clinopyroxenes define one end-member, and Oldoinyo Lengai clinopyroxenes represent the other end-member, while the Crater Highlands' samples are of a transitional composition. The compositions of the other minerals (olivine, feldspar, and magnetite) confirm this theory. According to mineral chemical data, the Black Belly samples crystallised in several steps under high pressures (5.6 to 6.6 kbar) and temperatures (750 to 900°C) from an alkali basaltic melt. Considering the new chemical and thermobarometry mineral data presented here and the structural evolution of the region, Black Belly cannot be petrologically part of Oldoinyo Lengai. Instead, it defines an end-member of a series, with Oldoinyo Lengai representing the other extreme and the Crater Highlands volcanoes in a transitional position. [ABSTRACT FROM AUTHOR]

A survey of entomopathogenic nematodes was conducted in Croatia between 2016 and 2017. The steinernematids were recovered in two out of 100 soil samples from agricultural land characterized as loamy soils with acidic reaction. Molecular and morphological identification was used to distinguish the nematodes. The isolates were identified as two different strains conspecific with Steinernema feltiae. The variations in morphometrical characteristics of infective juveniles (IJs) and males were observed among Croatian strains and with the original description. The analysis of ITS region revealed the greatest similarity of Croatian strains with Slovenian B30 and English A2 strains, which together comprised a monophyletic group in evolutionary analysis. This is the first record of steinernematids, namely S. feltiae in Croatia.

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Our data verified the relationship between meteorological factors and the fluctuation of the groundwater level. The rate of evaporation dominantly affected the rise and depth of the groundwater level. It is characteristic for the study site that there is an inverse relationship between the elevation of the groundwater observation wells and the depth of groundwater, and the difference between the levels of groundwater in the separate wells reflected the differences in the elevation between the wells. Our observations refuted our previous assumptions, as in the wells not only the concentration of salts changed but also the chemical type of the water. This can be attributed with great probability to the lateral flow of the groundwater, which is caused by the vertical fluctuation, but can be caused by other geological factors as well. We reached the conclusion that the vertical and sometimes lateral movement of the groundwater affects the development of soils in a given area. It means that the reason behind the mosaic-like appearance of the soil cover of a given area can be searched in the local differences of the chemical composition of the groundwater, which is a major factor of the spatial variability of the salt accumulation of soils. The observations and analytical results point to that the soils of the study site have developed under the effect of fluctuating groundwater and the elevation is a dominant factor of the spatial variability of the soil salt accumulation. The level of groundwater, the flow of groundwater and its composition show relationship with the surface elevation, and their effect is modified by the geological stratification, which results in a variable appearance of soil salt accumulation and native vegetation. [ABSTRACT FROM AUTHOR]

Within a 300 x 600 m complex heterogeneous sodic grassland two techniques were compared for assessing soil salinity. The standard technique is based on repeated field instrumental measurements at 420 points. The alternative technique was performed with the use of numerical simulation of salt accumulation carried out on 3 profiles. These profiles have been selected as representatives of the distinct classes, or map strata of salt accumulation, distinguished with preliminary statistical clustering of the instrumental measuring points. Simulated values were extrapolated for the 3 strata distinguished. The maps obtained with the two techniques were statistically correlated. The use of numerical simulation is cost-effective. Further improvements are expected from a combination of improved numerical simulation and utilization of more strata. Research and publication was supported by the EU Program No. PL970598, (Contract No. ENV4-CT97-0681) and the Hungarian Scientific Research Fund (OTKA) (Project Nos. T 023271, T025623, T 030738, T 037731). [ABSTRACT FROM AUTHOR]

Dominant halophytes, such as Plantago maritima, Aster tripolium, Artemisia santonicum, Puccinellia limosa, Festuca pseudovina and Lepidium crassifolium were monitored for their colonization by arbuscular mycorrhizal fungi (AMF) for two vegetation periods, sampled by monthly frequency. Two saline sites (A: Apajpuszta and Z: Zabszék) were selected for the survey due to their similar physical and chemical soil characteristics (including the salt level and salt specific anions) and the distinct site use (pasturing or not) or water regime (as drought or temporally flooded at the vicinity of the Zabszék lake). Colonization of arbuscular mycorrhizal fungi greatly depended on the plant species and their physiological status, such as the mycotroph or non-mycotroph character. In this respect the highest mycorrhizal intensity (M%) and arbusculum richness (A%) was found on the Plantago maritima, while Puccinellia limosa was the less dependent species on mycorrhiza fungi. A characteristic seasonal dynamism was found at both saline sites, for all sampled halophytes. A maximum mycorrhizal colonization was recorded in late spring and early summer, when there was an increased plant-physiological initiative for the helpful symbiosis (i.e. intensive vegetative and/or generative phases of the hosts). The rate of fungal intensity in the root system (M%), and especially the arbusculum richness (A%) on the other hand was found to be dependent on the site use and the water fluctuation in the soils. A more versatile dynamism of the mycorrhizal colonization was found therefore at the vicinity of the Zabszek lake with the permanent water fluctuations. Under more drought stressed conditions an increased mycorrhizal colonization and functioning (arbusculum richness) was found, generally preceeding the high environmental stress, which was deleterious for both symbiont partners. Such mycorrhizal dynamism in the rhizosphere, however, seems to be a common strategy between the hosts and the microsymbionts in the "struggle for life" process in the Hungarian steppe. The present work was supported by the Hungarian National Scientific Research Fund (OTKA) (Grants T0 46610 and T 37731) and the EU Framework-5 MYCOREM project. [ABSTRACT FROM AUTHOR]

An internet-based land valuation system is being developed to replace the scientifically obsolete Hungarian land valuation system, the so-called AK ("Gold Crown") ratings. The new system is supported by a GIS and it is unique in its capability of providing an up-to-date index of soil quality and land value. The geographical information is provided by national map databases on genetic soil maps and soil attributes at the scale of 1:10.000, combined with cadastral maps, digital terrain model, topographic map, orthophotos of aerial photographs and agronomic field records. The automated algorithms are easy to update, can be made legally binding and can provide a transparent system for land taxation, calculation of subsidies, appropriation. Given that detailed (1:10,000 or finer) soil map coverage will be completed for all lands of Hungary (at date only 60% of the croplands have soil maps), this way a multifunctional system will be available that promotes an optimum use of land resources. The presented work was supported financially by the National Research and Development Programme (OM-4/015/2004 NKFP and GVOP (AKF) - 2004 - 3.1.1 grants). [ABSTRACT FROM AUTHOR]

The statistical analysis of salinity data from samples collected yearly from genetic soil horizons of 69 points of the Hungarian Soil Information and Monitoring System between 1992 and 2000 showed changes in time. There is a strong atmospheric control over the groundwater level and the resulting soil salinity. Weak statistical association was established between either the pattern of yearly soil salinity changes in the second (10-20 cm) and third (30-40 cm) genetic horizon and the groundwater observation stations or the soil types. In the area of Kecskemét there was a tendency of decreasing soil salinity patterns, while around Békéscsaba a tendency of increasing soil salinity patterns, as illustrated by the correspondence biplot. Regarding soil types, the solonetzic meadow soil showed a tendency of increasing salinity. It was concluded that the statistical analyses of the monitored data must be carefully planned in order to provide the optimal background data as independent data from all those available to accompany the monitored soil data as dependent variable. The presented work was supported by the Hungarian National Scientific Research Fund (OTKA, T37731) and by the National Research and Development Programme under OM-4/015/2004 NKFP and GVOP (AKF) - 2004 - 3.1.1 grants. [ABSTRACT FROM AUTHOR]