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THE EFFECT OF LONG TERM FERTILIZATION
ON GROWTH AND YIELD OF STRAWBERRY
K. Smolarz
Research Institute of Pomology and Floriculture, Poland
In the year of 1923 a permanent experiment with soil fertilization
w?as established at Skiemiewice on Experimental Field of Warsaw'
Agricultural University. One group of trials consist of plots on which
a pattern of different mineral fertilization and limmg, without ma
nure has been employed. Various crops excluding leguminous plants
were grown. It allows to study the influence of severe deficiency of
mineral nut- rients on growth and yield of chosen plants.
The soil, on which experiment was established, is podsolic, drained,
containing in the upper layer about 16 °
o
of clay and silt and about
l, 3 % of humus. The experimental field was divided into a few' parts
with six fertilizing treatments. The experiment was set in systematic
design with three replications of each plot. The plot size w'as 10 x 5
m. At the begining nutrient doses per ha amounted: 45 N, 30
PjOsjand 60 K
2
O, since 1975 they were raised to: 90 N, 60 P
1
O
5
, and
110 K
2
O kg/lia. Liming has been performed even fourth year with a
dose of 1,6 t CaO/ha.
Our experiment with strawberry fertilization was established on
tw'o stripes of this field: the one, with exception of CaNPK combi
nation, had acid soil (0,CaNPK, NPK, PK, PN and KN), and the
second stripe was slightly acid, with the exception of NPK combina
tion (Ca, CaNPK, NPK, CaPK, CaPN and CaKN).
Two strawberry cvs - Senga Sengana and Talisman were planted
at distance of 25 x 80 cm on each plot. The following measurements
were recorded: growlh, flowering, yield and leaf nutrient content.
It was found that only during first two years, after planting the
yield of both cultivars w'as highest on plots with full fertilization
(CaNPK) and lower on unlimed plots (NPK). It the following years
soil acidity did not influenced the growlh and yield of strawberries.
The lack of nitrogen limited yield to the greatest extend.
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