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well. The effect of these treatments can be interpreted by the decreasing soil pH. While
improving soil pH (limed group) the conditions of mineralization would be better and
the amount of Nmin was higher than the control (Table 3).
The cumulated Norg was varied between 39.02 and 55.60 mg/kg according to
treatments. The lowest value was obtained in N2P2K2Ca2Mg2 treatment. It can be
explained by the better circumstances of mineralization. Results of applying one sided
N treatments pointed out that the rate of mineralization was lower compared to the
control and especially the limed treatments. Furthermore, it was found that the
treatments of NPK group had not effect on the amount of Norg.
The amount of sum of N forms was the highest in the case of treatments of limed group.
Treatments of NPK group have a negative effect on the amount of sum of N forms
compared to the control. It can be established that increasingly applied N not improved
the rate of mineralization remarkably.
Furthermore, the 0.01 M CaCl2 soluble N-fractions are in mainly inorganic forms
under incubation period but the content of organic forms also significant (Table 3.).
The relationship between the Nmin and time could be studied from the periodical data of
incubation (Table 4 and Figure 1).
According to results typical relationship was established N mineralization vs. time
(Figure 1). In spite of the different treatments the shapes of the obtained curves were
analogous. Logarithmic rate equation was founded in the case of all treatments.
Difference was established between coefficients of correlations and intercepts (Table
4.). Differences were explained the above mentioned effects of treatments. Liming
increased, one-sided N treatments decreased the amount of Nmin.
Cumulated Nmin (mg/kg
250
200
150
100
50
0
0 4 8 12 16
Time (weeks)
Figure 1: Relationship Nmin vs. Time
230
Control
N1
N2
N3
NPK
Limed