Abstract: Aim of this research is to determine spatial
variability of soils, nutrients in soil and yield for sunflower production to
assess variable rate fertilisation. Materials were sunflower field, and GNSS.
Seed variety was Limagrain 5542. Total size of the research field was 35.8
ha. Soil samples were taken from 0-30 cm and 30-60 cm depths. Soil texture, saturation point (%), pH at
saturated soil, Lime (%), total salinity (%), CaCO3, organic
matter, useful P (P2O5), useful K (K2O),
field capacity (%) and wilting point (%) were determined. Soil texture was
found mostly clay but clay loam and a sandy clay loam texture was also
determined. Mean values and standard deviations for saturation point 57.35%
and 7.44%, pH 7.30 and 0.66, salt 0.07 and 0.01, lime 7.63 and 0.68, organic
material 1.29% and 0.17%, P2O5 18.22 and 2.52, K2O
146.05% and 30.82, field capacity 30.34% and 4.07%, and for wilting point
19.18% and 2.72. Mean yield was 2100 kg/ha. Required fertilisers will be 285
kg/ha Ammonium Sulphate (21%N) and 115 kg/ha Calcium Ammonium Nitrate (26%N)
for constant rate fertiliser application as conventional application. If this
fertiliser is applied as variable rate; amount of fertilisers will be 115
kg/ha Calcium Ammonium Nitrate (26%N) for whole field and 285 kg/ha Ammonium
Sulphate (21%N) should be applied for 250 ha. field size. Urea (46%N)
suggested as 130 kg/ha for 100 ha. According to the results, fertiliser
requirement of the sunflower field is not constant. Fertilisation necessity
is spatially determined. Fertiliser application with spatial variable rate
will increase yield, quality and decrease fertilisation cost and
environmental effects.
Key words: Sunflower, Precision agriculture, Spatial variability, Variable rate
fertilisation
|