Application of Na and Partial Substitution of K-Na in Differrent Varieties of Sugarcane Planted on Inceptisol Soil

Indonesian Sugar Research Institute

ISRO ISMAIL

Senior researcher at Indonesian Sugar Res. Institute,
Jln. Pahlawan 25 Pasuruan, Indonesia.

ABSTRACT

Green house and field experiments have been conducted to evaluate the effects of Na and partial
substitution of K-Na on nutrient status of soil, growth and yield of sugarcane, juice quality, and sugar yield.
Three factors (varieties: PS 82-3605 and PS 78-2274-P4B; KCl dosages: 0, 40, 60, 80, 100% of standard
dosage; and NaCl dosages: 0, 20, 40, 60 % equivalent to standard KCl dosage) have been combined in a
randomized block design (green house experiment) and a split plot design (field experiment) with three
replications. In the green house experiment, a certain level of Na resulted in a positive effect on the sugar
yield. Dealing with NaCl dosage, the result showed that the highest sugar yield (229 g/pot) was reached by
the addition of 125 kg NaCl/ha. This beneficial effect of Na was due to the increase of sugarcane weight and
juice quality. There was an indication that Na was required by sugarcane and could inhibit the accumulation
of K in juice. Substitution of KCl (20-40 % of its dosage) by NaCl showed no negative effect on sugarcane
growth. The treatment of 60% KCl (240 kg/ha) + 40% NaCl (125 kg/ha) gave the highest sugar yield (243 g/
pot), while the yield of the standard K treatment (400 kg KCl/ha) was only 187 g/pot. Results from the field
experiment showed that partial substitution of K-Na did not influence the sugarcane weight, rendement, and
sugar yield. PS 82-3605 was superior than that of PS 78-2274-P4B and there is no difference in substitution
capacity of K-Na for both varieties.

Key Words: Potassium, sodium, sugarcane, substitution, varieties, soil properties