Joint International Conference on Long-term Experiments ...

proves that the highest yield can be achieved by 75 % water supply on calcareous
chernozem and marshy meadow soil and by 50 % water supply level on brown forest
soil. It can also be stated that the effect of nitrogen fertilization was not modified by the
different water supply. The positive effect of nitrogen treatments was detectable in the
dry matter production of plants at each cuts (significant at P = 0.1 % level).
The nitrogen content of plants is the highest (2.81 %) on marshy meadow soil
(P = 0.1 %), while on brown forest soil and calcareous chernozem the nitrogen content
of ryegrass was lower, 1.34 % and 1.91 %, respectively (Table 4). The tendency is in
accordance with the original total nitrogen contents of the experiment soils (Table 1).
The higher water supply decreased the nitrogen content of plants in almost every
treatment and soil combination (P = 1.0 % or 5.0 %).
In the mean of the experiment, the amount of nitrogen extracted per pot reduced with
time (1st cut: 87.7; 2 nd cut 42.8 and 3 rd cut: 37.2 mg N per pot). The total amount of
nitrogen extracted by the three cuts is also considerable with 167.7 mg per pot. The
decrease in the amount of nitrogen extracted can be explained by the gradually
decreasing yield.
Table 4: Nitrogen content (%) of the ryegrass 1 st cut
W.c. (%) Soil site N supply (mg kg -1 ) (A)
(C) (B) 0 40 80 Average
Pallag 1.13 1.27 1.83 1.41
50 Látókép 1.38 2.00 2.52 1.97
Dombos 1.85 2.90 3.72 2.83
Average 1.45 2.06 2.69 2.07
Pallag 1.00 1.27 1.52 1.27
75 Látókép 1.35 1.78 2.45 1.86
Dombos 2.10 2.75 3.55 2.80
Average 1.48 1.93 2.51 1.98
Pallag 1.06 1.27 1.67 1.34
Average Látókép 1.36 1.89 2.49 1.91
Dombos 1.97 2.83 3.64 2.81
Average 1.47 2.00 2.60 2.02
Table of variance
Factor FG MQ F SD 5%
A 2 7.72 291.5 *** 0.09
B 2 13.27 501.0 *** 0.09
A*B 4 0.56 21.1 *** 0.16
C 1 0.15 5.71 * 0.08
A*C 2 0.08 2.85 + 0.13
B*C 2 0.02 0.82 0.13
A*B*C 4 0.05 1.99 0.23
Error 51 0.03
*** Significant at P=0.1 % level; * Significant at P=5.0 % level
+ Significant at P=10.0 % level
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