engleski

Ameliorative PK-fertilization and liming impacts on soil status

Five steps of PK-fertilization were applied in spring of 2004 on Pavlovac acid (pHKCl = 3.99) soil(Bjelovar-Bilogora County) moderately supplied with phosphorus (available P2O5 according AL-method: 9.40 mg/100g) in amounts as follows: a = ordinary fertilization (kg/ha: 125 P2O5 + 82 K2O), b=a + NPK-1, c=a + NPK-2, d=a + NPK-3 and e=a + NPK-4. The fertilizer NPK 10:30:20 was source of P and K (using in amounts 416, 1249, 2082, 2916 and 3748 kg/ha, for the treatments a, b, c, d and e, respectively). Nitrogen amount (375 kgN/ha) was equilized for all five treatments by addition of correspondingle quantities of CAN(calcium ammonium nitrate: 27% N). The experiment was conducted in four replicates (basic plot 77 m2). Subsequent intervention in the experiment was liming (10 tones/ha) of half of the area with granulated fertdolomite containing 24.0% Ca + 16.0% MgO + 3.0% N + 2.5% P2O5 + 3.0% K2O. Remaining two replicates have been used as control. At third soil sampling two soil samples were taken from each basic plot. Soil sampling (0-30 cm) were made in three terms as follows: at start of the trial (April 3, 2004), November 15, 2005 and September 3, 2009. According to the results of AL-method, the five steps of PK fertilization significantly increased the average content of soluble phosphorus and potassium in soil. The liming had a similar significant effect on the available phosphorus but liming caused insignificant decrease in available potassium. Hence, mineral fertilization and liming simultaneously increased available phosphorus, but effects on the potassium were opposite. Also, mineral fertilization and liming had a different impact on soil pH since mineral fertilization significantly decreased and liming significantly increased soil pH.

fertilization ; liming ; pH ; phosphorus ; potassium

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