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• Change of mineral and organic nitrogen forms in a long term fertilization experiment (literature)

  43-47

  Judit Horváth

  János Kátai

  Views:

  112

  The research topic has timeliness, since the rational utilization and protection of the soil, besides the conservation of its diverse functions is part of the sustainable development. Research of the long-term experiments is esentially important, because it can model the term effects in the same place, under the same conditions. If we want to get accurate informations about the occured changes, way and danger of changes, we should track the resupply and effect of the mineral nutrients and the removed quantity of nutrients with the harvest. Nitrogen is an essential element for living organisms, it is present in the soil mainly in organic form. In general only only a low percentage of the total nitrogent content can be used directly by plants in the soil. This inorganic nitrogen is produced by the transformation of organic contents through mineralization processes and it get into the soil by the fertilization. The plants incorporote the mineral nitrogen into our bodies. This is how nitrogen turnover is realized when mineral forms become organic and organic forms become mineral.

  The purpose of our paper is to make a literature before our research.

• Nitrogen Content of Hungarian Soils and Nitrogen Fertilization

  51-61

  Tamás Németh

  Views:

  90

  For crop production and agricultural production, the most important natural resource is the soil that can optionally renew. Paralelly with this, soil plays a major role in the geological and biological cycle of elements. As a result of the big (geological) and small (biological) element cycles, the elements and combines neccessary for organisms can accumulate in the soil creating suitable living conditions for plants and other organisms. Soil is a heterogenous system both horizontally and vertically, and soil constituents show great variety in all the three dimensions, in addition, most of the parameters can also change between two examination dates. When talking about the factors influencing plant production, one should take into account this variation and heterogenity in time and space. When making fertilization recommendations, these factors should all be considered. In any consultation system, most of the mistakes and errors made are due to the unsatisfying soil testing and the negligence of soil heterogenity. In the practice of fertilization the biggest mistake is the improper soil sampling, then comes the methodical mistake of soil testing, which is followed by the inaccuracy of instrumental analysis and the subjectivity of result evaluation, but the latter two are negligible compared to the others. Under normal, i.e. production conditions, the quantity and distribution of nutrients in the soil are greatly dependent upon the applied technology, the amount and form of the applied natural and artificial fertilizers and the quality of fertilization.
  Fertilization recommendations are needed because in the layer which is accessible for plant roots only a part of the nutrient content is available for plants in a specific production cycle. An illustration of this is that though the upper 1 m layer of an average chernozem soil contains more than 5000 kg N, 12000 kg K2O and 1500 kg P2O5 (form of expression mostly used in Hungary), the application of fertilizer doses which are just fractions of these quantities is essential. This is due to the fact that the available amount of the total nutrient content depends from the quality of soil, the environmental factors (the physical and chemical qualities of the soil) and the specific nutrient’s qualities (solubility, adsorption). Knowledge of these processes and the examination of the factors influencing the actual nutrient content are vital for working out a fertilization practice, which does not put more strain on the environment than neccessary.

  All of the above mentioned should be considered when applying inputs in the fields. In a well-functioning practice that considers the economic and environmental conditions (unfortunately the present production and economic conditions do not enable an appropriate level and degree), three nutrients are supplemented generally (and were supplemented in the last decades): nitrogen, phosphorus, potassium.
  Studying the nutrient balance of the Hungarian field production’s last hundred years, we can draw some interesting conclusions.
  The nutrient balance became positive for nitrogen and potassium in the second half of the 1960’s, while for phosphorus it was positive from the first half of the 1960’s and this period lasted until the end of the 1980’s.
  Neither before the 1960’s, nor since the 1990’s has the amount of nutrients supplemented in a specific year reached the amount of the nutrient uptake of the same year.

• Effects of some herbicides on the microbiological characteristics of soil nitrogen cycle under maize plantation

  93-100

  Zsolt Sándor

  Magdolna Tállai

  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.

• Examination of CO2 emission of different stubbles on a chernozem soil

  53-59

  Györgyi Kovács

  Views:

  80

  Applying alternative soil cultivation methods based on reduced disturbance of the soil more favourable conditions can be created in order to increase the organic matter content of the soil and the availability of the nutrients for the crops. In complex soil tillage experiment – in 1997 was set on – at Karcag, as the element of the investigation of soil reduced and conventional tillage systems. There is close correlation between the degree and intensity of CO₂-emission from the soil and the structural state and organic matter content of the soil. In order to quantify the increased CO₂-emission from soil due to soil preserving cultivation systems, in situ CO₂-emission of soil was measured by means of an ANAGAS 98 infrared gas analyser. The soil type of the investigated plot is meadow chernozem solonetz in the deeper layers, a soil type that is characteristic
  for the Trans-Tisza Region of Hungary. In this paper the results gained from the measurement on different stubbles are published, as we consider stubbles the most suitable state when the effects of different soil cultivation systems on the microbiological activity of the soil can be compared. Experimental data provided information about the length of the time period when CO₂ emission increasing effects of soil cultivation are observable. Studying the effect of different soil cultivation methods on the CO₂ emission from chernozem soil is indisputably actual and needs more efforts as it can contribute to develop a more environmental friendly agricultural production. The main goal of these measurements was to determine the effect of soil cultivation technologies and certain agrotechnical elements on the factors of the soil carbon cycle.