Land productivity evaluation systems are developed to predict the crop growing potential of lands on the basis of their attributes. The Hungarian land evaluation system presently in use, known as the gold crown system, was developed in the 19 th century and its rating is based on profitability. This system does not give an exact description of the productivity potential of the land and includes no information on the environmental characteristics of the soils. In recent decades most European countries have adopted land evaluation methods based on land and soil parameters. In the 1980s a quantitative land evaluation method of this type was introduced in Hungary as well. In this system the effect of soil attributes on the level of fertility was expressed in numerical terms by soil mapping units. This system was again replaced by the gold crown system during the political changes in the early 90s. However, using a soil evaluation system (where the relative production potential of the land is expressed in a quantitative manner) together with measurements of soil degradation or amelioration an integrated method could be developed to express various land quality/land productivity relationships. This approach could help decision makers – along with land users and environmental scientists – to choose profitable and sustainable land use types and methods at local and regional levels. In this context, sustainable land use means biomass production with the highest efficiency without harmful environmental side effects. This paper introduces a soil evaluation methodology based on the Hungarian genetic soil classification. The productivity evaluation system was worked out on the basis of long-term (6 years) yield data collected from 1019 fields in the Balaton Upland region (Central Western Hungary) and large-scale genetic soil maps of the study region.
The separation of low molecular weight compounds labelled with125I has gained importance with the advent of radioimmunoassay (RIA) in which overwhelmingly125I-labelled analytes are used as tracers. The chloramine T labelling method proved to be the most suitable procedure to introduce radioiodine atom via aromatic electrophilic substitution either in the thyronine molecule or in the tyrosine methyl ester (TME) side chain coupled as a prosthetic group to different compounds which do not possess phenolic hydroxyl groups.
3,3′-diiodothyronine, 3,3′,5-triiodothyronine, 3,3′,5′-triiodothyronine and thyroxine was labelled with125I and/or131I by the use of the chloramine T method.1.2 The labelled products were separated by adsorption chromatography using Sephadex LH-20 dextrangel as adsorbent and aqueous
solution of ethanol as eluent.
It was shown that the desorption kinetics of chemisorbed iodine in electron donor solvents obeys an equation obtained by solving
a set of first order rate laws expressing the energetic non-uniformity of the solid surface. Reference desorption activation
energies were calculated and compared with the CT complex formation free energies.