Nitrogen effect on production, nutrients uptake and nitrogen-use efficiency of shallot (Allium cepa var aggregatum)

Certainly nitrogen it is one of the most essential mineral for the plant. Shallot (Allium cepa var aggregatum L.) was grown under fully irrigated conditions in a field experiment in the Central Java Indonesia to study and determine (i) optimum nitrogen dosage for bulb yield, (ii) nutrients uptake and (iii) nitrogen use efficiency. The field experiment was performed as a randomized complete block design with five nitrogen levels (100, 200, 300, 400, 500 kg/ha-1) with six replicates. Our results showed that increased nitrogen rate enhanced shallot production. It was shown that the optimum dosage is 265 kg/ha-1. The highest nutrients uptake was reached by 300 kg N/ha-1. But, increasing the applied nitrogen rate decrease the NUE. The range of NUE values recorded was between 0.24 and 1.20 g bulb per g nitrogen.