Browse

You are looking at 121 - 130 of 1,515 items for :

  • Earth and Environmental Sciences x
  • Refine by Access: All Content x
Clear All

Tenyészedény-kísérletben vizsgáltuk, hogy a szárazságstressz és az arbuszkuláris mikorrhiza gomba (AMF) oltás milyen változást okoz a búza gyökérnövekedésében, és ez hogyan követhető nyomon a gyökér–talaj rendszer elektromos kapacitásának (CR) in situ mérésével.

A kísérletet randomizált blokk elrendezésben végeztük két búzafajtával (Mv. Hombár őszi és TC 33 tavaszi), kétféle öntözéssel (optimális és szárazságstressz) és kétféle oltással (oltatlan és AM-gombával oltott), 12 ismétlésben. A tenyészidőszakban monitoroztuk a CR-t, valamint mértük a sztómakonduktanciát és a levelek klorofilltartalmát (SPAD-értékben). A kísérlet végén TTC-teszttel vizsgáltuk a gyökerek életképességét, mikroszkópos vizsgálattal becsültük az AM gomba gyökérkolonizációját, valamint meghatároztuk a gyökér- és hajtástömeget.

A vízhiány szignifikánsan (9–35%-kal) csökkentette a búzafajták gyökértömegét, mely a mért CR-értékekben is tükröződött. A szárazság okozta CRés biomassza-csökkenés jelentősebb volt a TC 33, mint az Mv. Hombár esetében. A CR monitorozásával kimutattuk a növények stressz utáni regenerációját és a fajták eltérő gyökérnövekedési dinamikáját. Az AMF oltás csökkentette a CR-t és a biomassza-produkciót (29–42%-kal), vélhetően az intenzív (84–87%-os) gyökérkolonizáció és a növénynevelés körülményei (erős szárazságstressz) következtében. Az oltás optimális öntözés mellett növelte a sztómakonduktanciát és a gyökér vitalitását. A vízhiány azonban csökkentette a gyökér életképességét. A klorofilltartalom leginkább a búzafajták között mutatott eltérést az Mv. Hombár nagyobb SPAD-értékével. A gyökértömeg és -kapacitás között szoros lineáris korrelációt (R2 = 0,792–0,865) találtunk. A TC 33 fajta regressziós egyenesének nagyobb meredeksége a nagyobb hajtástömegből eredő nagyobb fajlagos vízfelvételre vezethető vissza.

Eredményeink alapján a CR-mérés alkalmas a gyökérnövekedési dinamika monitorozására és a környezeti hatások detektálására. A roncsolásmentes eljárás egyéb növénymorfológiai és -élettani vizsgálómódszerek hasznos kiegészítője lehet.

Restricted access
Agrokémia és Talajtan
Authors:
M. Jolánkai
,
Á. Tarnawa
,
H. F. Nyárai
,
Z. Szentpétery
, and
M. K. Kassai

Long-term trials are established in order to explore and observe plant and soil interrelationships in situ. Long-term trials can be described as live instruments providing ceteris paribus conditions in temporal sequences.

This review provides an introduction to major long-term trials in Hungary and in other parts of the world. It gives a brief summary of the origins of plant nutritional research, beginning with some data from Homer and the willow tree experiment of van Helmont, as well as the discovery of physiological processes by von Liebig, Lawes and Boussingault. The most profound long-term trials, like the Orto Botanico in Padova, the Linné Garden in Uppsala and the Broadbalk in Rothamsted are presented in the paper.

The agronomic, educational and scientific benefits of the major Hungarian long-term trials are also discussed, from Westsik (1929) to Martonvásár and the National Plant Nutrition Trials (OMTK) set up in 1963. There is a list of experimental sites giving information on the most important recent long-term trial locations and their activities.

Restricted access

Energy and metals are essential resources in the 21st century and with the economic and technical development are more and more required. The fulfilling of these requirements leads to the need to produce both more ore and energy. Considering these goals, the project CHPM2030 (“Combined Heat, Power and Metal extraction”) was launched in January 2016, focused on the characterization of European mining regions that can be linked to both metal extraction and renewable energy production. The aim of this project is to convert ultra-deep metallic mineral formations into an “orebody-enhanced geothermal system” to co-produce energy and metals. This study will focus on two mining areas (Recsk in Hungary and Neves-Corvo in Portugal), considered CHPM2030 case studies, comparing them regarding mineral (ore) and geothermal potential in terms of heat-flow density values and their implication in temperatures in depth estimations. Especially, when it concerns geothermal energy, the surface demand is an important factor to consider, so wider studies are required.

Open access
Agrokémia és Talajtan
Authors:
R. K. Gangwar
,
M. Makádi
,
M. Fuchs
,
Á. Csorba
,
E. Michéli
,
I. Demeter
, and
T. Szegi

Soil samples were collected from salt-affected soils (Solonetz) under different land uses, namely arable (SnA) and pasture (SnP), to investigate the effects of land use on microbiological [basal soil respiration (BSR), microbial biomass carbon (MBC), dehydrogenase activity (DHA) and phosphatase activity] and chemical properties [organic carbon (OC), humic ratio (E4/E6), pH, electrical conductivity (EC), ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), available forms of phosphorus (P2O5), potassium (K2O), calcium (Ca2+), magnesium (Mg2+), sodium (Na+)] and on the moisture content.

The results showed that the two sites, SnA and SnP, were statistically different from each other for all the microbiological and chemical parameters investigated except Na+ and moisture content. Higher values of MBC (575.67 μg g-1), BSR (9.71 μg CO2 g-1 soil h-1), DHA (332.76 μg formazan g-1 day-1) and phosphatase activity (0.161 μmol PNP g-1 hr-1) were observed for the SnP soil. Great heterogeneity was found in SnP in terms of microbiological properties, whereas the SnA plots showed more homogeneous microbiological activity due to ploughing. 75.34% of variance was explained by principal component one (PC1), which significantly separated SnA and SnP, especially on the basis of soil MBC and P2O5. Moreover, it was concluded that the pasture land (SnP) was microbiologically more active than arable land (SnA) among the Hungarian salt-affected soils investigated.

Restricted access

Willow was cultivated as an energy crop in a field experiment. The brown forest soil was treated with an inorganic fertilizer (ammonium nitrate−AN: 100 kg ha -1) or with various organic or mineral soil amendments (municipal biocompost–MBC: 20 t ha −1; municipal sewage sludge compost–MSSC: 15 t ha −1; rhyolite tuff–RT: 30 t ha −1; willow ash−WA: 600 kg ha −1), or their combinations (AN+MBC; AN+RT; AN+WA, MSSC+WA) in four replications. Nineteen months after the soil treatments the macroelement-rich amendments (MBC, MSSC) enhanced the harvested fresh shoot yield most significantly (up to 41% as compared to the untreated control), and also the shoot diameter and shoot height of the willow plants. Most of the treatments enhanced the uptake of N (9.8-23.5%) and K in willow leaves, but the concentrations of P, Mg, Ca, Fe and Zn in the leaves were reduced. The toxic element (As, Cd, Pb) accumulation of willow shoots was negligible.

In a 4-year field experiment the effects of the mineral fertilizers AN and AN+calcium-magnesium carbonate (CMC) were studied on the mineral nutrition of the leaves and wood yield of black locust trees cultivated as an energy crop. The brown forest soil was treated with 300 kg ha −1 annual doses of these fertilizers as top-dressing in June 2009, May 2010 and May 2011. Both fertilizers caused a three to four times increase in the nitrate content of the upper soil soon after their application in June. By the end of the vegetation period (in December) the nitrate concentration in the soil was similar to that in the control plots. The nitrogen content of the leaf stalks (petioles) and leaves, however, was only slightly higher in the treated plots. As a trend, fertilization increased the phosphorus and reduced the calcium uptake in the leaf stalks and leaves, while the magnesium content was not influenced. In March 2012, when the whole trees were harvested, 22% or 28% higher aboveground fresh shoot weight was detected in the AN or AN+CMC treatments than in the control.

Restricted access

The estimation of environmental risk caused by pollution with potentially toxic elements (PTE) is usually carried out using the (3+1) step sequential extraction procedure suggested in 1993 by the Community Bureau of Reference (BCR). In the 1st step the water-soluble, exchangeable and carbonate-bound element content is extracted with acetic acid. In 2002 a fractionation procedure based on the application of supercritical CO2, subcritical H2O and of a mixture of subcritical H2O/CO2 was proposed, which allowed the water-soluble and carbonatebound element contents to be extracted separately from sediment or soil samples weighed into the preparative column of a supercritical fluid extractor and diluted with quartz sand in a mass ratio of 1:20. The aim of the present study was to develop a new reduced-size column construction with which this dilution rate could be decreased to 1:2. A kinetic study was performed to determine the extraction time necessary for samples with different carbonate contents and the extracted element contents were compared to the results of the BCR sequential procedure on the same samples. It was established that fractionation using the reduced-size column may be a rapid way to obtain more reliable information on the easily mobilizable (watersoluble and carbonate-bound) PTE content of soils and sediments than was previously available to supplement BCR fractionation.

Restricted access
Agrokémia és Talajtan
Authors:
János Kátai
,
Thomas Döring
,
Magdolna Tállai
,
Andrea Balla-Kovács
,
István Henzsel
,
Marianna Makádi
,
Zsolt Sándor
, and
Imre Vágó

The size of the arable land is constantly decreasing all over the world due to severe anthropogenic disorders. Plant production therefore has to be adapted to changing environmental conditions along with the proper selection of crop varieties and the application of sustainable environmental technologies which also consider economic aspects. The investigations were carried out in the Westsik long-term fertilization experiment near Nyíregyháza, East Hungary, which was set up in 1929 (89 years ago). Alternative forms of nutrient supplies (A) (green manure, straw with and without fermentation, organic fertilizer with and without inorganic fertilizer supplements) were used in different crop rotations. The test plant was potato (Solanum tuberosum L.) and the soil type sand with a low humus content (Arenosols). A further long-term experiment is located on calcareous chernozem soil (Chernozems) in Debrecen (set up in 1983, 35 years ago). In one part of this experiment, organic farming (OF) has been carried out with a pea, winter wheat and maize crop rotation for over 15 years with no inorganic fertilization. In another block in this experiment, changes in soil properties as a result of the medium and high doses of fertilizers applied in intensive farming (I) were evaluated with a maize (Zea mays L.) monoculture as the test plant.

The results obtained with alternative nutrient supplies (green manure, fermented and unfermented straw, farmyard manure, fertilization) proved that the soil organic carbon content increased to varying degrees in humus-poor, acidic sand soil. The organic matter content of the soils increased in response to the treatments, contributing to a significant enhancement in soil microbial parameters (MBC, saccharase, dehydrogenase and phosphatase enzyme activities).

The carbon dioxide production and saccharase enzyme activity in organic plots (OF) were significantly lower than in intensively farmed (I) soils. At the same time, in the case of organic farming (OF) the microbial biomass carbon, phosphatase and dehydrogenase activity were significantly higher in OF plots than in I plots. Compared to the control soil, MBC was 7-8 times higher in organic plots and 1.3-3.8 times higher in intensive plots.

Organic farming on chernozem soil generally resulted in higher microbial activity (MBC, phosphatase, saccharase and dehydrogenase enzyme activity) than in either intensively farmed chernozem or in the case of alternative farming (A) on sandy soil.

Restricted access
Agrokémia és Talajtan
Authors:
László Simon
,
Marianna Makádi
,
György Vincze
,
Zsuzsanna Uri
,
Katalin Irinyiné Oláh
,
László Zsombik
,
Szabolcs Vígh
, and
Béla Szabó

A small-plot long-term field fertilization experiment was set up in 2011 with willow (Salix triandra x Salix viminalis ’Inger’) grown as an energy crop in Nyíregyháza, Hungary. The brown forest soil was treated three times (in June 2011, May 2013, May 2016) with municipal biocompost (MBC), municipal sewage sludge compost (MSSC) or willow ash (WA), and twice (June 2011, May 2013) with rhyolite tuff (RT). In late May – early June 2016 urea (U) and sulphuric urea (SU) fertilizers were also applied to the soil as top-dressing (TD). These fertilizers and amendments were also applied to the soil in 2016 in the combinations; MBC+SU, RT+SU, WA+SU and MSSC+WA. All the treatments were repeated four times. In July 2016 the highest nitrogen concentrations in willow leaves were measured in the U (3.47 m/m%) and SU (3.01 m/m%) treatments, and these values were significantly higher than the control (2.46 m/m%). An excess of nitrogen considerably reduced the Zn uptake of the leaves, with values of 39.5 μg g-1 in the U treatment, 53.4 μg g-1 in the SU treatment, and 63.5 μg g-1 in the control. All other amendments or TDs, except for WA, enhanced the specific potassium concentrations in willow leaves compared to the control. No significant quantities of toxic elements (As, Ba, Cd, Pb) were transported from soil amendments or TDs to the willow leaves. In July 2016 the most intensive leaf chlorophyll fluorescence was observed in the MSSC and MSSC+WA treatments.

Restricted access

The Mecsekalja Zone is a strike-slip fault zone that plays an essential role in the structural framework of South Transdanubia. The metamorphic and deformation history of the crystalline basement of the Mecsekalja Zone has been determined thus far based exclusively on a few surface outcrops and near-surface samples. The Szentlőrinc-1 (Sztl-1) well penetrated the shear zone at a depth of approximately 2 km and brought drilling chips from a 220-m-long section of the basement to the surface. The aim of this study is to reconstruct the metamorphic and deformation history of the Mecsekalja Zone along the Sztl-1 well using these tiny samples. These drilling chips consist of single mineral and rock pieces that are dominated by quartz grains. This study concentrates on the detailed analysis of quartz grains utilizing the physical conditions of metamorphic evolution as well as ductile and brittle deformation to determine the chemical composition and rheology of quartz. The evolution of the studied area can be determined by evaluating analytical data measured by Raman spectroscopy, LA-ICP-MS, and FTIR spectroscopy. These data suggest that the maximum temperature of the early regional metamorphism was 500–575 °C, the temperature of the subsequent ductile deformation was below 500 °C including recrystallization occurred between 400 and 475 °C. During the structural evolution of the study area, two independent, single deformation events occurred. The earlier ductile deformation event was followed by a brittle event through the reactivation of the former ductile shear zone. Our model is in accordance with previous results concerning the evolution of the Mecsekalja Zone, thus, the shear zone, with an identical evolution, can be extended toward the southwest at least to the Sztl-1 well.

Open access

The Late Valanginian–Early Hauterivian iron ore deposit and related formations at Zengővárkony (Mecsek Mts., South Hungary) provided a relatively rich microfauna of foraminifera, crustacean microcoprolites, and sponge spicules. Benthic foraminifera are recognized in decreasing abundance: Glomospira cf. gordialis (Jones and Parker 1860), Lenticulina sp., Spirillina sp., Nodosaria sp., Epistomina sp., and Trocholina sp. A Hedbergella sp. indicates the presence of planktonic foraminifera around the ore deposit. Besides this microfauna, sponge spicules (diactine-type criccorhabds and anactine-type rhax forms) are first recorded from this environment. Rock-forming quantities of various ichnospecies of crustacean microcoprolites are recorded. Favreina hexaochetarius, Palaxius tetraochetarius, and Palaxius decaochetarius isp. provided statistically evaluated quantities in thin sections, which point to a complete crustacean ichnofauna from juveniles to adults. Four different microfossil assemblages are recognized from the Apátvarasd Limestone Fm: (a) Glomospira-dominated foraminifer assemblage, (b) diverse crustacean microcoprolite assemblage dominated by Palaxius, (c) monotypic Favreina assemblage, and (d) diverse sponge-dominated assemblage. These assemblages are similar to that of the Recent Aegean Sea hydrothermal field communities. The remains of an undetermined crinoid from dissolved rock sample may indicate a vivid sea-bottom environment.

Open access