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The antagonistic effect of thirteen Pseudomonas aeruginosa and thirteen strains of other Pseudomonas species was studied on the soil-borne phytopathogenic Rhizoctonia solani and Fusarium solani fungi.  The inhibition of pathogen colony growth was tested with two different in vitro techniques using the same type of culture media. In case of the spread slant technique the antagonists induced a significantly stronger inhibition on the growth of pathogens than in case of spot transfer. Among the 26 investigated Pseudomonas strains, P. aeruginosa strains were generally more effective against the fungal pathogens. Rhizoctonia solani proved to be affected to a greater extent by the bacterial strains studied than the Fusarium solani representative. The possibility of in vitro strain selection of biocontrol microbes is being further discussed .

The primary (1 ^st year) and the after-effects (2 ^nd , 3 ^rd year) of N fertilizers (KNO ₃ , NH ₄ Cl) on the soil-plant-atmosphere system were studied in a three-year greenhouse pot experiment with and without maize plants. The two- and three-year balances of the fertilizer N uptake and gaseous N losses were also analyzed. The cumulative values of the gaseous losses showed a similar trend in all years, significant differences were not obtained. On the basis of the three-year balance, the gaseous loss in the planted and unplanted pots was 18-22% and about 37-39%, respectively. Consequently, there was a 50% decrease in denitrificated gaseous losses of fertilizer N due to plant N uptake. The cumulative gaseous loss, calculated by the difference method, was significantly higher in cases of KNO ₃ applications than in NH ₄ Cl treatments, as an assumed  consequence of the intensive denitrification. It was found that the gaseous loss was not influenced by soil moisture.  In contrast to the gaseous losses, the values of plant N uptake and soil mineral N content showed significant differences in the years studied, as a result of the quick transformation of mineral N to organic N, the non-complete homogenization of the total soil amount, the seasonal climatic differences in the greenhouse during the years studied, and consequently the different microbiological activity. The plant N uptake was found to depend significantly on the fertilizer N form. Results obtained by the difference method and the ¹⁵ N-tracer technique were very similar. In the case of KNO ₃ treatment and higher soil moisture (WHC = 80%) plant N uptake was more intensive, ranging between 48-57% (calculated by the difference method), and 35-51% (calculated by the ¹⁵ N- tracer method) in the first year (1993). It can be concluded that 60-100% of the fertilizer N was used from the soil by plant uptake and gaseous losses, which depends mainly on the treatments and the soil moisture during the first year. These values changed between 7-17% in the 1 ^st year after-effect and between 1-5% in the 2 ^nd year after-effect.

Five soil P-test methods were compared on the soils of the network of unified Hungarian P fertilization long-term field trials. The effect of P application on the soil P-test values was significant on the different P levels and sites. The average effect of the sites varied between 1.5-fold (H ₂ O method) and 3.7- fold (AL-method). The amounts of extracted P increased in the order of H ₂ O-P < Olsen-P < Pi-P < AERM-P < AL-P < Corrected AL-P. For studying the relationships between the P values extracted by the different methods, acidic, calcareous and all soils groups were taken into account as a basis. A good correlation was found between the Pi- and AERM-methods in each soil group. Within the acidic soil group, pH has a much less expressed effect on AL-P values, presumably this was the reason why the strongest correlation in this soil group was found between the AL- and the Corr. AL-P methods  The next step in our research will be to calibrate these soil-P tests with plant P uptake and yield responses.

Authors studied the effect of copper nutrition on the yield, kernel weight and raw protein content of winter wheat. Copper was applied in the form of copper tetramine hydroxide that was produced from a clean copper containing waste originating from microelectronical industry. After suitable chemical transformation this waste can be used as an excellent secondary raw material for the preparation of copper fertilizer. The foliar application of copper tetramine hydroxide complex at the phenological phase of tillering significantly increased the yield, kernel weight and raw protein content of winter wheat. The calculated copper doses that gave the maximum yield, raw protein content and kernel weight were 1.04, 1.12 and 0.77 kg ha ^-1 respectively.

The pot experiment - carried out in 2000 under greenhouse conditions - was set up with seven soils differing in Cd and Pb contents and three test plants ( Lolium perenne L. cv. Georgikon), lettuce ( Lactuca sativa L. cv. Balatonzöld) and white mustard ( Sinapis alba L. cv. Sirola) with four replicates. From the seven experimental soils five samples (S1-S5) were collected from agricultural areas (arable sites) and two (S6-S7) from spoil-earth, with extremely high Cd and Pb contents.  The pots, each containing 1 kg air-dry soil, were kept at constant soil moisture (60% of maximum water capacity of the experimental soils) by daily watering, while pots were watered to weight once weekly. Before sowing the test plants: 50-50-50 mg N, P ₂ O ₅ and K ₂ O was applied to the experimental soils to maintain the same nutrient supply. The above-soil plant parts were cut after four weeks. Fresh and dry weights of plants were determined after harvest. The aim of the experiment was to obtain results of Cd and Pb uptake by different plant species in relation to the heavy metal content and different characteristics of soils. The following conclusions were drawn: No definite correlation was found between the biomass production of the three test plants and the heavy metal content of the soils at early growth stage. The heavy metal concentration range in the soils and plants differed. In the case of Pb the soil concentration interval was broader than that of the plants'. The opposite was observed for Cd, where the plants had a wider concentration interval. Comparing the Pb and Cd concentrations of above-ground plant parts, Pb concentrations varied in a narrower interval. The maximum values of Pb content exceeded the Cd content levels, although the mobility of Pb in the soil-plant system is significantly lower. The comparison of Cd and Pb concentrations of plants and soils proved these differences. The Cd concentration of plants was 8-231% of the total Cd content of soils. The Pb concentration of plants was the 0.8-28% of the total Pb content of the soils, respectively. Comparing the three plants in respect of Cd concentrations the order found was as follows: ryegrass < white mustard < lettuce. In case of Pb, the order depended on the Pb content level (lower or higher) of the experimental soil. Symptoms of phytotoxicity were observed only on lettuce plants grown on the contaminated soils (S6, S7).

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.

New, quantitative methods and data sources for characterizing small scale soil resources have been demonstrated. AVHRR and coarse spatial resolution DEM were designed for mapping large areas of the world quickly and cost effectively. The method combines digital elevation data, “ground truth” information, including the soil taxonomic class for measured soil locations, and a time series of satellite images to form a digital soil database. The results show that using ancillary information such as AVHRR data and DEM derivatives from the national to continental level surveys is among the most promising tools for geographers and soil surveyors. The AVHRR data is often used for land cover studies but its usefulness in soil studies has not yet been proven. This study is a representative example of the usefulness of AVHRR data in characterizing the soil-forming environment and delineating soil patterns, particularly when integrated with other data for describing the soil landscape, such as the DEM, slope, curvature and PDD. The predictive power of AVHRR and similar low spatial resolution satellite data sources could be further improved with the development of soil sensitive filters. Mention should be made of the potential improvement of the products derived from these data sources with the use of better quality data provided by satellites that have been launched recently. Neither the AVHRR nor the DEM-derivatives show high correlation with the soil classes, but both represent a great portion of the environmental variability. In general, the more uncorrelated information is extracted from DEM and AVHRR, the better explanation of the spatial soil variability is achieved with an integrated use of them. The images of AVHRR time series show a relatively low correlation, thus each of the new dates adds much potential information on the soils. The studies also highlighted the great help of surface vegetation in soil remote sensing, as indicated by the high R² value of Band 1 and NDVI. The importance of the short-term weather history of the study area was also demonstrated.  Terrain information and terrain variables were primarily developed for large scale local studies. Small scale mapping of large regions presents different issues, like over-generalization and over-smoothing of the soil information. The terrain features with smaller extents are dissolved into a larger neighborhood. As a smoother terrain map is created, a lot of detail is lost and less variability is observable. Many of the terrain attributes are useless with this approach. Elevation, slope, relief intensity, potential drainage density and the curvature variables are the most informative digital variables for characterizing the soil-landscape in small scale inventories.  The resulting soil databases will have all the advantages of quantitatively derived databases, including consistency, homogeneity, and reduced data generalization and edge-matching problems. Although the results from the above procedures are believed to be accurate enough to serve as a basis for global and regional studies, they should be checked and further revised by local and regional experts to ensure quality. Research should continue on improving the procedures, augmenting the pedon data with new field sampling, and incorporating new image and DEM data sources. One of the most important results of these studies is the demonstration of the usefulness of these data sources for small scale soil mapping and the overall validity and representatitivity of the AVHRR-terrain/soil correlation within the temperate region of the world. Further studies will need to be performed to test the use of AVHRR and terrain data for other climate zones of the World, where potential problems, like continuous cloud cover, may occur.

Soil texture is an important input parameter for many soil hydraulic pedotransfer functions (PTFs) of the day. Common soil particle-size classes are required to be able to uniformly determine the texture of soils. However, it is not always possible - due to different national classification systems - and much valuable information is disregarded while either deriving or applying PTFs. One way to get common particle-size class information is to interpolate the particle-size distribution (PSD) curve. Advanced interpolation solutions are becoming available, but there is always uncertainty associated with these techniques. Another possibility is to measure all PSD curves in such a way that it is compatible to the commonly used classification systems. A new automated measurement technique is introduced that can easily provide PSD data compatible to any (and all) of the existing national and international classification systems at the same time, without the burden of extra labour. A computerized measurement system has been developed to record density changes in a settling-tube system in any discretional (small) time steps, which in turn allows the derivation of a quasi-continuous PSD curve. The measurement is based on areometry (Stokes-law), thus the system is compatible to the most commonly applied settling-tube measurements. The new evaluation method of measured values takes into consideration the density changes along the areometer-body so it avoids the problem of reference point determination. The theory and setup of the system are explained and measurement examples are given. The presented comparative measurements show good correspondence with conventional settling-tube results, and the reproducibility of the measurement shows to be very high. This technique does not require more sample preparation than past methods. The automated reading requires less manpower to perform the measurement - which also reduces human error sources. However, it provides very detailed PSD data that has advantages, like revealing multi-modality in the particle-size distribution or providing data that complies with any of the classification systems.

For estimating the lime requirement (LR) in some countries it is accepted to use hydrolytic acidity suggested by Kappen, which is based on a single time extraction of hydrogen- and aluminum ion with calcium acetate. More accurate results could be achieved if we measured the total surface acidity (TSA) of soils. For this reason it is an improvement to use a direct measurement method and equipment, which is suitable to estimate the results of long-term processes and TSA, via investigating the kinetic properties of desorption. The method of measurement: A pH electrode is dipped into continuously stirred soil suspension containing background salt (e.g. KCl), and it isconnected to a computer using an amplifier and A/D converter. A computer program has been developed that controls an automatic burette, which adds the base solution into the system if pH is less than the pre-adjusted value (e.g. pH 6.5 or pH 6.8) and stops adding when pH reaches this value. For evaluation, the amount of added base vs. time data series can be used. With increasing time the amount of added base keeps to a constant (asymptotic) value. The program fits an exponential associate function on measured data, and outputs the asymptotic value connected to infinite time, which can be used to calculate LR.  Supposing that there are two processes with different rates, in this case the function can be created as the addition of two first order kinetic sub-processes:  The faster process that takes place on the outer surfaces features easily removable acidity, and the slower process probably describes processes within the deeper pores. The fitting error of parameters is about 0.3-1%, which means that the TSA value, based on these measured data and method can be estimated with high accuracy.  The measurement is fully automated. The evaluation is based on extrapolation, so the precision of results increases with the number of measurement points and the length of measurement time. Depending on the application, a quick measurement with approximate results or a longer measurement with more precise results can be chosen.

Most of the factors initiating food or fluid intake have already been studied, but much less is known about those terminating ingestion. We have hypothetised that discomfort originating from the gastrointestinal system may be one of those factors. Gut distension cause pain if the intestinal volume changes but merely discomfort if only the tension of the gut wall increases. It seems that mild unpleasantness (i.e. discomfort) arising from the gut as a result of moderate (quasi-isometric) distension, among and in concordance with other factors, may significantly reduce intake and hence contribute to physiological satiety. The arising discomfort can be detected by measuring the amount and rate of the ingestion, by recording and analysing ingestive behavior by taste-aversivity and taste-reactivity tests, etc. Conclusions of all experiments point to the same direction: tension increase in the gut wall causes discomfort and results in decrease of intake, i.e. satiety.