Efek Aplikasi Pupuk NPK cair terhadap P-tersedia, Serapan P, dan Bobot Umbi Bawang Merah (Allium ascalonicum L.) di Tanah Inceptisol Jatinangor

Abstrak

Shallots are a high-value horticultural commodity that requires optimal phosphorus (P) availability to
support growth and bulb production. However, Inceptisol soils have limitations in providing phosphorus
due to their high fixation capacity and low organic matter content. This study aimed to examine the effect
of liquid NPK fertilizer application on soil phosphorus availability, plant phosphorus uptake, and shallot
bulb yield in Inceptisol soil. The experiment was conducted using a randomized complete block design
(RCBD) with six treatments: control, recommended NPK fertilizer, and four doses of liquid NPK fertilizer
(½, 1, 1 ½, and 2 doses), each with four replications. The results showed that liquid NPK fertilizer
application significantly increased soil phosphorus availability, plant phosphorus uptake, and both fresh
and dry bulb weights compared to the control. The 1 ½-dose liquid NPK fertilizer treatment resulted in an
available P content of 12.72 ppm, a phosphorus uptake of 3.28 mg plant⁻¹, a fresh bulb weight of 78.63 g
clump⁻¹, and a dry bulb weight of 63.86 g clump⁻¹, which were not significantly different from the
recommended NPK treatment. This indicates that applying 1 ½ doses of liquid NPK fertilizer can serve as
an equivalent alternative to conventional granular NPK fertilizer in providing phosphorus for shallot
cultivation. Thus, the application of liquid NPK fertilizer at 1 ½ times the recommended dose can be
proposed as an effective and efficient fertilization strategy to improve shallot productivity in Inceptisol soil.