Nutrient budgeting of shallot (Allium cepaL. Aggregatum group) in Central and East Java, Indonesia

Abstract

Indonesia has several shallot production centers along with varieties of shallot which have different productivities. NPK fertilization is one of the efforts to improve shallot yields. The purpose of this study was to determine the shallot yield and nutrient budgets in shallot field. The production centers chosen for this study were in Bantul, Central Java and Nganjuk, East Java, Indonesia. Biru variety is common variety of shallot planted in Bantul, while Thailand variety is planted in Nganjuk. The results showed that the yield of Biru variety was 10.43 t ha-1 and Thailand variety was 4.43 t ha-1. The total NPK of soil in Bantul and Nganjuk was very low. In Bantul N fertilizer was applied at average dose of 88.57 kg ha-1, whereas in Nganjuk at 107.73 kg ha-1. However N uptake both in Bantul and Nganjuk was low, so N fertilizer application efficiency was only 43.26 and 18.32%, respectively. In Bantul K fertilizer was applied at average dose of 168.27 kg ha-1 whereas in Nganjuk was 80 kg ha-1. However K uptake in both areas was low, so K fertilizer application efficiency was only 30.96 and 27.33%, respectively. In Bantul P fertilizer was applied at 162.17 kg ha-1, whereas in Nganjuk at 164 kg ha-1. However P uptake in both areas was very low, so that P fertilizer application efficiency was also very low, i.e., only 0.25 and 0.14%.