B. Szabó, Emese2021-06-282021-06-282010-12-15Acta Agraria Debreceniensis, No. 41 (2010) , 7-112416-1640https://hdl.handle.net/2437/316310The 0.01 M CaCl 2 universal extractant is known all over Europe since the 90’s. During my research, I exam the phosphorus content determined in 0.01 M CaCl 2 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 CaCl 2 -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 CaCl 2 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 CaCl 2 -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 CaCl 2 was able to assess the deficiency and the excess of phosphorus causing negative impacts on environment as well.application/pdf0.01 M CaCl2-Pphosphorus fertilizationmeadow chernozem soilfolyóiratcikkOpen Accesshttps://doi.org/10.34101/actaagrar/41/2672Acta Agraria Debreceniensis41Acta agrar. Debr.