Correlation of plant nutrients uptake with shallot production in alluvial soils

Plant analysis can be used as a guide to diagnose status and as a fertilizer recommendation tool for shallot. This study aims to determine the nutrient requirements of shallot based uptake of N, P and K on alluvial soil, to understand the correlation between nutrients uptake and bulb yield, and also to know the nutrients status of shallot varieties. Research activities had been carried out at two locations: Cirebon (West Java) and Brebes (Central Java) with alluvial soil types, from May to August 2010. The experimental design at each location was a Split Plot Design with three replications. The main plots were varieties, viz Bima and Bangkok. The subplots were doses of N, P and K fertilizer, consisting of six combinations of fertilizer N, P and K fertilizer dosage range is 85-255 kg N/ha, 0-150 kg P2O5/ha and 0-180 kg K2O/ha. The results showed that the alluvial soil has low N, very high P and K status. The response of plant growth, bulb yield and nutrients uptake (N, P and K) of Bima and Bangkok were relatively similar to the application of N, P and K fertilizer. Bima has plant growth, bulb yield, nutrients uptake, and efficiency of fertilizers lower than Bangkok. Application of N, P and K fertilizer in the dose range 85-255 kg N/ha, 0-150 kg P2O5/ha and 0-180 kg K2O/ha had no significantly difference on growth and bulb yield. Fertilizer requirements for Bima was 160 kg N/ha, 90 kg P2O5/ha and 121 kg K2O/ha, meanwhile Brebes was 170 kg N/ha, 83 kg P2O5/ha and 138 kg K2O/ha. Correlation of N, P uptake on Bima and Bangkok production were quadratic. Meanwhile, P uptake was quadratic for Bima and linier for Bangkok. The nutrient status of Bima was sufficient for N, P2O5 and very high for K2O. Meanwhile the nutrient status of Bangkok was very high for N and P2O5.