Soil texture and its characteristics besides water
characteristics can play an eminent role in potato (
Solanum tuberosum
L.) production. Therefore, a soil and water quality
index (SWQI, %) was derived to investigate the effect
of combination of soil and water characteristics (sodium
adsorption ratio for water and soil, electric conductivity
of water and soil, pH for water and soil, organic matter in
the soil, and soil texture index) on yield and properties of
‘Spunta’ potatoes produced under center pivot irrigation
system. This index was formed studying separately the
effect of irrigation water quality and soil texture on yield,
water use efficiency, tuber modulus of elasticity, and tuber
shape index of ‘Spunta’ potatoes. Field results demonstrated
that the lowest potato yield was approximately 34.12 t ha
-1 at
SWQI 79.63%, and the highest potato yield was 37.79 t ha
-1
at SWQI of 30.93%. The lowest water use efficiency was
approximately 6.09 kg m
-3 at SWQI 30.93%, and the highest
water use efficiency was 6.83 kg m
-3 at SWQI 79.63%. The
lowest tuber modulus of elasticity was approximately 3.98
N mm
-1 at SWQI 21.7%, and the highest tuber modulus
of elasticity was 4.74 N mm
-1 at SWQI 79.63%. Finally,
the tuber shape index was approximately 342% at SWQI
79.63%, 418% at SWQI 21.72%, and 403% at SWQI
30.93%, which belongs to long and very long shapes. The
soil and water quality index could be a useful tool to get
relationships among water and soil characteristics, yield,
and other properties of the potato crop.
