The aim of this paper was to provide further information about the nitrogen mineralization processes of soil. A modified incubation technique was applied to establish the amount of easily soluble mineral and organic N forms during the incubation period. An acidic sandy soil was used for incubation, which was sampled from the „Westsik” long-term field experiment. The incubation was carried out on fifteen selected soil samples which were received different treatments since the experiment was set up.
From the obtained results, the amount of potentially mineralizable N and the mineralization rate constant were determined. Results of chemical analysis and biological interpretation of results are discussed.
The cultivation technology for those plant, that play a key role in arable land production need to be renewed in order to reduce production costs and to protect arable land. The modernisation of technologies can only be achieved by applying appropriate tillage systems. Our measurements were carried out on chernozem soil with lime deposits at the Látókép Experimental Station of the Center for Agricultural Sciences, Debrecen University, in long term tillage experiments set up in 1989. We examined the typical physical parameters, the albedo, field capacity, the bulk density of the soil, organic carbon content (humus %) and the measured pH-values in the water solution within the two tillage variations. We have also modelled nitrogen cycle formation in different treatments.
A significant difference occured between the albedos of the two soils, which may be the result of significant amounts of stem remaining on the surface in the case of the reduced tillage method. The yellow, waxy stem of maize reflects 21% of the sun’s rays, especially at the beginning of the vegetation period, when its decomposition has only just started. This delys the warming up in early spring, which delays the sowing time of maize and reduces evaporation. In the two tillage variations, the water management characteristics do not differ practically, the wilting point field capacity are in accordance. In reduced tillage methods, the so-called „plough-pan” can be well measured at 15-20 cm, while in winter ploughing it is at 30 cm. The humus % of the soil does not differ in the two tillage variations, but due to the difference in bulk density this means a different humus and organic nitrogen content. The organic nitrogen content is greater in the reduced tillage method. On the basis of pH value evaluations, we could not detect significant differences in the two tillage variations. The organic nitrogen content of areas where reduced tillage method was applied is higher than in areas where conventional winter ploughing was applied.
In Hungary, there are 57 LTFEs included 13360 plots of them 51 trials elder than 20 years, more than 50 years are 32 trials and 6 less than 20 years old. Compared to the 2003 statistical data, some 26 LTFEs ceased to operate in the course of the last 15 years. All research workers and scientist have to do the best to preserve the recently still existing LTFE’s. This paper presents the list of the currently active LTFEs with some comments including the locations, year of setting and the number of plots.