Search

Published After
Published Before

Search Results

  • Effects of Tillage Systems on Physical Status and Organic Matter Turnover of the Soil
    42-45
    Views:
    152

    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.

  • Effects of some herbicides on the microbiological characteristics of soil nitrogen cycle under maize plantation
    93-100
    Views:
    71

    Nitrogen is a key element for the living organisms and influence not only for the quantity but for the quality of the yield, considerable. Availability of nitrogen from the soil is influenced by several microbiological processes of the Nitrogen-cycle. Among the intensive agricultural production the herbicide application cannot be omitted more information needs therefore about the inhibitor effect of herbicides on the different microorganisms.
    An experiment was set up on calcareous chernozem soil under maize culture. Effect of four different herbicides (Acenit, Frontier, Merlin, and Wing) was investigated. The effect of herbicides was measured to four microbiological parameters of the Nitrogencycle (abundance of nitrifying bacteria, nitrate solubilisation, biomass nitrogen and urease enzyme activity). There were singledouble-  and five times of recommended doses of herbicides applied for two onsecutive vegetation periods.
    From the results of the different doses of herbicides, the following can be stated:
    – The Acenit has a stimulating effect on nitrifying bacteria in general. The Frontier and Merlin also influenced the quantity of nitrifyers, however in certain cases decreased in another cases increased the number of bacteria.
    – The double doses and five times doses of herbicides was found to be increasing the nitrate content of soil, -especially in 2006.
    – The quantity of microbial biomass nitrogen increased in the 60% of treatments and decreased in the 40% of the treatments.
    – Except of the result of Wing in 2006 and Merlin in 2005, the effect of simple dose herbicides was the smallest on the urease enzyme activity. According to the results the effect of Merlin was positive; the effect of Wing was negative on the soil enzyme’s activity.
    Regarding the application of four different herbicides in three  different doses on the microbiological parameters of soil (at two consecutive years-) in 39% of the treatments has resulted a significant inhibitory effect, 28% of the treatments, however have significant stimulating effect on the parameters measured. More than 50% of the inhibitory effect was measured in case of the Wing, at more than 50% of the Frontier the microbiological parameters have not changed.

  • Effect of agrotechnical factors on the activity of urease enzyme in a long term fertlization experiment
    43-48
    Views:
    126

    The soil is a natural resource, the fertility preservation is an important part of the sustainable development. We have to monitor the transformation dinamics of the organic nitrogen-containing substances, to get accurate information about the changes of the nitrogen cycle in the soil.

    Physical and chemical properties of the soil and the microorganism effect on the organic matter in the soil – in addition to the composition of organic matter. Wide variety of extracellular enzymes are present in this decomposition. These enzymes help in the transformation of the macromolecules to transforming low molecular weight compounds so they will be available during the assimilation.

    The urease enzyme, catalyzes the hydrolysis of urea to CO2 and NH3. The urease is widely spread in the nature, it is present in the microorganisms, plants and animals.

    We found that the soil moisture content, the rotation and the fertilization affect to the amount of urease in spring. Furthermore, we get significant difference between the irrigated and non irrigated samples in the second period of the year. Based on our results we can state that the activity of urease was higher in spring 2014.

    The objective of our study was to present how the different agronomic factors affect on the activity of urease in a long term fertilizationexperiment.