Joint International Conference on Long-term Experiments ...

MATERIALS AND METHODS
An organic and mineral fertilization field experiment was established with a randomized
block design, four replications, and two crop rotations on Keszthely in 1963. The initial
soil (Eutric Cambisol) parameters of the long-term experiment were as follows: (KA =
37; pHH2O = 7.3, TOC = 0.87; AL-P2O5 = 27; AL-K2O = 135 mg kg -1 ). The plot size was
98 m 2 . In the present study, only the results of crop rotation potato - maize - maize -
winter wheat - winter wheat and 11 of the 15 treatments of the experiment (35, 70, 105 t
ha -1 FYM or mineral fertilizer with equivalent NPK doses or FYM+NPK combinations
as shown in Table 1) are discussed. In case of simple, double and triple doses, FYM was
distributed before sowing of the potato for 5 years, timed half-and-half to the potato for
5 years, and to the maize (in the autumn of the previous year) in the 3 rd year,
respectively. Grain yields in cereal units [CU] (potato tuber yields were multiplied by
0.3.) in 1998-2006, pHH2O, organic carbon (TOC), P, K and mineral N-content of the 0-
300 cm soil layer (in increments of 30 cm, 4 sample per plot), as attributes of changes in
soil fertility were evaluated.
Composite soil samples were taken from the 0-20 cm soil layer after harvest, 10
samples for each plot. P and K content of the soil was determined applying ammonium
lactate extractant, which is used in Hungary for routine soil tests (Egner-Rhiem-
Domingo, 1960). TOC contents in the ploughed soil layer were measured by the
classical methods of Turin. Mineral-N was extracted with 1% KCl then NH4-N and
NO3-N were analysed by steam distillation and titration procedure.
Treatment
No.
Table 1. Selected treatments of the experiment
Codes of treatments kg NPK ha -1 yr -1
1. Control -
2. 1 FYM N44P38K49
3. 2 FYM N88P76K98
4. 3 FYM N132P114K147
5. 1 eqv N44P38K49
6. 2 eqv N88P76K98
7. 3 eqv N132P114K147
8. 1 FYM + 3 eqv N176P152K196
9. 4 eqv N176P152K196
10. 1 FYM + NPK N172P110K181
11. 1 eqv + NPK N172P110K181
Legends: 1 FYM= 35 t ha -1 farmyard manure in 5 years
1 eqv = mineral NPK equivalent to 35 t ha -1 FYM in 5 years
NPK = N640P360K660 in 5 years
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