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• Long-term field experiments in the crop production and agroecology

  267-272

  Tamás Kismányoky

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  177

  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.

• The effect of long-term fertilization on phosphorus content determined in different soil extractants on meadow chernozem soil

  7-11

  Emese B. Szabó

  Views:

  76

  The 0.01 M CaCl₂ universal extractant is known all over Europe since the 90’s. During my research, I exam the phosphorus content determined in 0.01 M CaCl₂ of the samples originated from the B 17 National Uniformed Long Term Fertilisation Trials in the experimental site Karcag, in the 40^th year of the experiment. Relationships between the CaCl2-P and the AL-P content of the soil, the average yields, and the phosphorus balance of the
  2006/2007 year were studied. From the results of the study it was concluded as follows:
  – Correlation was close (r=0.68-0.7) between the AL-P and CaCl₂-P. This is in accordance with the results of previous experiments in Hungary and other countries.
  – My studies confirmed that the calcium-chloride method indicates well the deficiency and the surplus of plant available phosphorus. In case of different degrees of negative balance, the amount of CaCl₂ extractable phosphorus showed no changes, or decreased, and in case of positive balance it increased exponentially by the long-term effect of P rates.
  – The 120 and 180 kg ha^-1 rates resulted in significant increases in the amount of CaCl₂-P according to the control and treatments that are not fertilized with phosphorus. The 60 kg ha^-1 rate didn’t result any increase as it didn’t meet the phosphorus requirement of winter wheat, and presumably the P-balance was negative in the earlier years as well.
  – It can be stated that the 0.01 M CaCl₂ was able to assess the deficiency and the excess of phosphorus causing negative impacts on environment as well.