bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing Methods Affecting the Antagonistic Ability of Pseudomonas Biocontrol Strains
Authors: Jevcsák I. , Oldal Bálint , Ködöböcz L. ,   et al.
Published: August 2004

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
.
Transformation of Nitrogen Fertilizers in Greenhouse Experiments
Authors: Nótás Erika , Debreczeni K. , Fischl K. ,   et al.
Published: August 2004

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.
Correlations Among Different P-Test Methods Studied in a Network of Hungarian P Fertilization Long-term Field Trials
Authors: Magyar Marianna , Csathó P. , Debreczeni K. ,   et al.
Published: August 2004

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.
Effect of P, Zn and Cu Fertilization on Crops on a Calcareous Chernozem Soil
Authors: Kádár Imre 
Published: August 2004

Both deficiency and
excess of P, Zn and Cu are common in soils and crops of Hungary. The excess and
deficiency of P occurring in agricultural soils and crops is a consequence of
previous fertilization practice. Zn deficiency occurs mainly on calcareous
soils well fertilized with P under maize, while Cu deficiency is often detected
on poor sandy soils and on organic soils under other crops. Zn and Cu excess
has been measured in city soils, in soils near highways and industrial areas. In the present paper the effect of P supply
is shown on yield and P/Zn ratios of crops, presenting the phenomena of the
P-induced Zn deficiency on a calcareous loamy chernozem soil. In an other
long-term field trial on the same soil, the effect of Cu and Zn loads was
studied on soil and crop. The main conclusions drawn from these long-term field
experiments are as follows: 1. An excess of available P in the plough layer of
this soil might be detected by the ammonium lactate (AL) method when the soil
analysis shows concentrations higher than 150-200 mg/kg P
2
O
5
.
The P/Zn ratios of 6-leaf stage shoots and harvested straw of maize grown on
these plots might be higher than 200, while that of grain 150-200. 2. In the
frame of a fertilization program, P-induced Zn deficiency can be counterbalanced
effectively on such calcareous chernozem soils with the application of P and Zn
fertilizers in a ratio around 10:1. 3. The Cu content of crops could not be
markedly raised by using CuSO
4
fertilizer, even with rates as high
as 270 or 810 kg/ha Cu. However, as an effect of increased NxP fertilization,
the Cu content of maize grain doubled, or that of maize straw was 4-times
higher. This is an important tool for the Cu enrichment of animal diet, when
maize straw is also used for animal feeding. 4. The soil and plant analysis
data are proper means of controlling soil fertility and crop nutritional status
when the soil and plant data are previously calibrated in long-term field
experiments.
Cadmium and Lead Uptake by Ryegrass, Lettuce and White Mustard Plants on Different Soils
Authors: Lehoczky Éva , Németh T. , Kiss Zs. ,   et al.
Published: August 2004

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).
Pedological Features of Red Clays in Northern Hungary
Authors: Fekete József , Stefanovits P. 
Published: August 2004

On the basis of the samples studied, which were gathered over the past
year, we were able to summarize the characteristics of red clays in Northern
Hungary. From the large selection of samples we chose 16 representative soil
profiles for our assessment. In order to characterize red clays we used data on
mechanical composition, cation exchange capacity and adsorption capacity as
well as the mineral composition identified by X-ray diffraction and
thermoanalytical studies. Following observations and conclusions drawn from our
study we were able to identify the categories of red clay in Northern Hungary:
1. Red clay of the Hegyalja region (Tokaj foothills); 2. Red soils of the
Cserhát and Szalonna Hills; 3. Red clays of the Aggtelek karst, the Torna Hills
and the Bódva Valley; 4. Red soils of the Bükk mountain range. 5. Red clays of
the Northern periphery of the Great Hungarian Plain. The following conclusions can be drawn from
the studies on the water permeability of the soils: Water permeability is
correlated with the pore space and the ratio of coarse pores. The bigger the
total pore space and the ratio of coarse pores, the better the water
permeability of the soil. If the clay content is higher the water permeability
is generally lower. In soils that contain montmorillonite the speed of water
permeability is lower than in soils containing kaolinite. Within the porous
system of bauxitic red clays containing kaolinite the volume of medium size and
coarse pores increases, resulting in better water permeability. In the upper
layers of soils covered with vegetation water permeability is much better. The
high amount of roots and root residues provides better soil structure and
porosity, thus improving water permeability.
Analysis of Soil Hydraulic Conductivity in Palm Plantations in the Saline Soils of the Oued Rhir
Authors: Cserni Imre 
Published: August 2004

The aim of the study was to determine K-factors of homogeneous zones in
palm-groves in order to make possible the interpolation of these values to
other similar areas, and by this way to help the calculation of draining
parameters. Another goal was to interpret the agronomical aspects of the
results. Investigations for the determination of conductivity factors
(K-factors) were carried out in the palm-groves of the Oued Rhir Valley. The
measurements - conducted three times -
were made by the auger-hole method. After boring the hole, a perforated
cylinder was placed into it to prevent falling in. K-factor values were
calculated after van Beers. The mean of the three calculations was given as the
end result for the K-factors. Our results show that K-factor values are
influenced by the porosity, type, bulk density and texture of soils, their salt
content and the form of gypsum. The K-factor was extremely high in case of
sandy soils and soils containing crystallized gypsum. Water conductivity was
moderate in case gley and pseudogley were located in deeper layers. The lowest
values occurred when gypsum was found in cemented coherent particles.
Salinization in deeper layers influenced hydraulic conductivity only in case it
was associated with finer texture and airless layers. Besides date production, the traditional growing of
nitrogen-fixing perennial legumes (alfalfa, Egyptian clover, melilot, etc.) in
palm-groves is essential. Systemic
flooding irrigation decreases the salt content of soils, increases date and
legumes yields. Legumes - by their root-system - improve the nitrogen balance,
structure and water drainage of soils. The green parts of the cultivated
legumes serve as fodder for animals (goats, sheep, cows), which turn it to
manure. This manure increases the nutrient supply of the soils for palm-trees
and vegetables. The positive results of stubble and root manuring (green
manuring) of legumes is also confirmed by experiments on sandy soils. The
elaboration of a good plant rotation is possible. At last, date and vegetables
produced in this way could be sold better on the world market as bioproducts.
An Equipment and Software for Improved Estimation of Soil Acidity
Authors: Czinkota Imre , Filep Gy. , Rékási M. ,   et al.
Published: August 2004

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.
Algateszt a foszfor felvehetőségének a vizsgálatára
Authors: Ördög Vince , Máté Ferenc 
Published: August 2004

A talajfelszínen a csapadékvízzel elmozduló és algásodást okozó foszfor mérésére, bár számos módszer áll rendelkezésre, értelemszerűen mégis az algatesztek a legalkalmasabbak. Kérdés az, hogy van-e összefüggés a talajtanban használatos kémiai és biológiai módszerekkel mért mobilizálható/hozzáférhető foszfor és az algateszttel nyert BAP (BioAvailable Phosphorus) értékek között? Helyettesíthetők-e a hosszadalmas algatesztek valamely eddig használt eljárással? A kérdés eldöntésére különböző P-tartalmú, 20 talaj- és 3 balatoni mederüledék- mintán végeztünk összehasonlító vizsgálatokat. A minták alapvizsgálati adatait és összes-P koncentrációját az 1. táblázatban foglaltuk össze. Mértük a minták összes-P és ammónium-laktát oldható P-tartalmát (DI GLÉRIA, 1962), a forró vízzel mobilizálható P-koncentrációt (FÜLEKY & CZINKOTA, 1998), valamint a vas-oxid-papírral kimutatható foszfort (SHARPLEY, 1993a). Elvégeztük a Neubauer- és az Aspergillus-tesztet (BALLENEGGER, 1944), az Olsen-féle Pvizsgálatot (OLSEN & DEAN, 1965), továbbá két szervezettel háromféle algatesztet (ÖRDÖG & DOBOLYI, 1997).
Az 1. ábrán a talajminták ammónium-laktáttal (AL), a NaHCO3-tal (Ols.), vas-oxid-papírral (V.ox.) és forró vízzel mobilizálható foszfor koncentrációját mutatjuk be, ill. ugyanezen P formák arányát az összes foszforon belül. A 2. ábra a Neubauer módszerrel (Neub.), a N-mentes (C.-N) és N-tartalmú (C.+N) BG-11 tápoldatban Cylindrospermopsis raciborskii-val, valamint a Scenedesmus subspicatus-szal (Sc.) mérhető hozzáférhető foszfor koncentrációját mutatja, ill. ugyanezen P formák összes foszforon belüli arányát. A 3. ábrán a „C.-N” algateszt és az Aspergillus niger teszt, a 4. ábrán pedig a „C.-N” algateszt és az AL-P eredményeit hasonlítjuk össze.
Az eredményekből megállapítható, hogy az ammónium-laktátos és az Olsenféle módszerrel mért értékek között statisztikailag szoros összefüggés állapítható meg, tehát egymással helyettesíthetők.
A talajtanban használatos kémiai és biológiai módszerekkel mérhető hozzáférhető/mobilizálható foszfor egyike sem mutat statisztikailag igazolható összefüggést az algatesztekkel. Talajtani módszerekkel tehát nem helyettesíthetők az algatesztek, másrészről azoknak a jelen dolgozatban bemutatott módszerei és teszt szervezetei nem alkalmasak a címben jelzett klasszikus talajtani kérdés megválaszolására.
Rhizobaktérium törzsek szaporodásának és vasmegkötő képességének nehézfém-érzékenysége
Authors: Várady György , Biró Borbála , Kucsma Nóra , Bayoumi H. E. A. F. , Kecskés Mihály 
Published: August 2004

A növények oltására is felhasználható Pseudomonasok, azaz a PGPR (növényi növekedést serkentő) rhizobaktériumok sziderofor- (vaskelát) képző tulajdonságuk miatt, a talajeredetű kórokozók távoltartásával, a növénytermesztésben is hasznosuló tevékenységet fejthetnek ki. A szideroforok képződésére ható tényezők ily módon hatással vannak a törzsek antagonista jellegének a kialakulására, és ezáltal az irányított biológiai védekezés hatásosságára is.
Laboratóriumi körülmények között ezért hazai talajokban nőtt különböző mezőgazdasági növények rizoszférájából származó, BIOLOG gyorsteszttel azonosított 11 Pseudomonas rhizobaktérium törzs nehézfém-érzékenységét tanulmányoztuk. A szaporodási képesség mellett a PGPR hatásban szerepet játszó sziderofor-termelő képesség ellenőrzése is megtörtént AgNO3, CoSO4∙7H2O és CrK(SO4)∙12H2O vegyületek 10, 40, 160 és 640 μM mennyiségeinek a hatására folyékony és táplemezes eljárásokkal.
Megállapítást nyert, hogy az alkalmazott nehézfémek nemcsak a törzsek szaporodási képességét, hanem a kórokozok távoltartásában fontos sziderofortermelő képességet is befolyásolták. Ezek mértéke és tendenciája ugyanakkor különbözőképpen nyilvánult meg a fémek típusától és az alkalmazott dózisoktól függően. A növekvő koncentrációk fokozatos toxikussága mellett a fémszennyezettségnek serkentő, szinergista módon kedvező tulajdonságai is előfordultak. A vizsgált, különböző élettani funkciók, azaz a Pseudomonasok szaporodása és vaskelátképző tulajdonságai a nehézfémekkel szemben eltérő érzékenységet mutattak. Az alkalmazott laboratóriumi technikák a rhizobiológiai monitoring alkalmas eszközeinek bizonyultak a nehézfémek károsító hatásainak megfelelő színtű detektálására is.
A talajlakó állatok és az endomikorrhiza-gombák közötti kapcsolatok szerepe a növények tápanyagellátásában
Authors: Seres Anikó , Bakonyi Gábor 
Published: August 2004

A dolgozatban áttekintjük a talajban élő állatok és az arbuszkuláris mikorrhizagombák (AM-gomba) közötti sokféle kapcsolatrendszert. Várható, hogy a klímaváltozások következtében növekszik a száraz időszakok gyakorisága. Ilyen körülmények között a mikorrhiza-gombák jelentősége a növények tápanyag- és vízfelvételében a jelenlegi állapothoz képest növekedni fog.
Célunk, hogy bemutassuk az állatok hatását az AM-gombákra és ezen keresztül a növényi tápanyagfelvételre, valamint a növények növekedésére.
A különböző talajlakó állatfajok hatása az AM-gombákra egyidejűleg lehet pozitív és negatív is, ezért a hatások eredőjeként tapasztalt jelenségek magyarázata sokszor igen bonyolult.
P—Zn kölcsönhatás mészlepedékes csernozjom talajon kukorica monokultúrában
Authors: Kádár Imre , Turán Tamás 
Published: August 2004

Szabadföldi P—Zn műtrágyázási tartamkísérletünket 1978 őszén állítottuk be löszön képződött, mély humuszrétegű, vályog mechanikai összetételű karbonátos csernozjom talajon, Intézetünk nagyhörcsöki kísérleti telepén. A talaj szántott rétege 5 % CaCO3-ot, 3 % humuszt tartalmaz; Ca, Mg, Mn és Cu elemekkel kielégítően, N és K elemekkel közepesen, P és Zn elemekkel gyengén ellátott. A talajvíz 13–15 m mélyen helyezkedik el, a termőhely aszályra hajló, vízmérlege negatív.
A 4P × 3Zn = 12 kezelést 3 ismétlésben, split-plot elrendezésben állítottuk be. A parcellák mérete 4,9x15=73,5 m². Főparcellaként a 0, 100 kg/ha/év, 500 kg/ha/5 év, 1000 kg/ha/5 év P2O5-trágyázás, alparcellaként a 0, 20, 40 kg/ha/5 év Zn-trágyázás szolgált szuperfoszfát és ZnSO4 formájában. Alaptrágyaként az egész kísérletben egységesen 200 kg/ha N-és 200 kg/ha K2O-műtrágyát alkalmaztunk NH4NO3 és KCl formájában. A termesztett kukoricahibrid az Mv-SC 580 volt. Az első 4 év eredményei alapján levonható főbb következtetések:
Kísérleti körülményeink között, ezen a foszforral gyengén ellátott talajon, az évenként adott 100 kg/ha P2O5-trágyázás kielégítheti a kukorica P-igényét. Előretrágyázás formájában ez a mennyiségű foszfor 4–5 évre számolva egyszerre is kiadható. Az 1000 kg/ha feltöltő P2O5-trágyázás gazdaságtalan és Znhiányt indukálva terméscsökkenéshez vezethet. Az AL-oldható P2O5-tartalom optimumát a 100–150 mg/kg érték jelezheti a szántott rétegben.Az egyoldalú, 1000 kg P2O5/ha adaggal előidézett P-túlsúlyt és szemterméscsökkenést a 40 kg/ha Zn-trágyázással lehetett ellensúlyozni. A KCl+EDTA módszerrel meghatározott Zn-tartalom optimumát 2–3 mg/kg talajbani koncentráció mutatta.Irodalmi adagokkal összhangban a kukorica kiegyensúlyozott tápláltsági állapotát a 4–6 leveles légszáraz hajtásban mért 0,3–0,5 % P és 30–60 mg/kg Zn, míg a címerhányáskori levél optimális összetételét 0,25–0,40 % P és 25 mg/kg feletti Zn-koncentráció-tartomány jellemezheti. A P/Zn arányának ideális értéke a vegetatív növényi részekben 50–150 közöttire tehető. Amennyiben ez a P/Zn arány jelentősen 200 fölé emelkedik, a Zn-trágyázás hatékony lehet.A P-túlsúly növelte a meddő tövek előfordulását 1978-ban, amikor szemtelítődés idején (augusztusban) aszály uralkodott. Ebben az évben a termő tövek 13–20 %-a bizonyult terméketlennek.
Stress related changes of cell surface hydrophilicity in Bacillussubtilis
Authors: Kovács T. , Bihari Z. , Hargitai A. , Mécs I. , Kovács K. L. 
Published: August 2004

The changes of cell surface hydrophilicity in Bacillus subtilis were analyzed in response to oxygen-limitation, heat shock, salt stress, pH-shock, phosphate- and carbon-limitation. Although cell surface hydrophilicity varied during growth phases, an increase of surface hydrophilicity was observed under several of these stress conditions. An observed drop in intracellular GTP and/or ATP may be an element of the signal transduction pathway leading to an increase in surface hydrophilicity in response to environmental stresses. Attachment of cells to soil particles under salt stress conditions is strongly influenced by the degS/degU two-component system, which thereby provides a mechanism for the bacteria to escape from the hostile environment.