SERAPAN N DAN P TANAMAN TEBU VARlETAS R 579 DAN PS 864 SEBAGAI LANDASAN UNTUK MENENTUKAN SAAT TEPAT PEMUPUKAN N DAN P

Abstract

The objective of this research are 1) to determine when N should be supplied based on uptake curve of nitrogen, 2) to determine when P should be supplied based on uptake curve of phosphorus, 3) to study correlation between N uptake and P uptake, and 4) to study correlation between N uptake and diameter and hight of stem. Two sugar can varieties (R 579 and PS 864) were cultivated on field and supplied with 800 kg ZA as nitrogen source and 100 kg SP36 as P source. Samples were taken after 30 days after planting (DAP) with interval of 15 days. The last sample were taken at 18 DAP. No experimental design were applied in this experimental, 3 samples were taken each variety and total of N was analized by using titration methid and P using wett destruction method with HNO, and HCLO. According to uptake curve of N and P, the first N supplay to both varieties (R 579 adn PS 864) should be excuted at 80 days after planting (DAP) and the second termin should at 135 DAP to R 579, but 120 DAP to PS 864. P should be applied at 70 DAP to both of varieties. N uptake of both varieties of sugar cane showed a positive correlation to P uptake and diamater, hight of stem as well