Effect of fertilizer discount on fresh fruit bunches production and Nutrients in North Sumatra Indonesia

Abstract

The low price of fresh fruit bunches a couple of years ago forced oil palm companies to make some efficiencies in the whole business process, including discounting the fertilizer expenses, which consequence in the Fresh Fruit Bunches (FFB) production declining in the first and second years onward. Reviewing the effect of fertilizer reduction on FFB production in commercial fields was challenging due to being confounded with many factors, including estate condition, infrastructure, climate, social, and management. Therefore it was better to assess from trials that tested the application of N, P, K, and Mg fertilizers with different rates to oil palm in a different locations on mineral soil in North Sumatra. Those trials illustrated that fertilizer discount would correct the FFB production accordingly from 3 up to 84%. In addition to this, climate, leaf nutrient uptake, and palm age play an important role in the decreasing FFB. An adequate water supply from the rainfall would stimulate a better leaf nutrient uptake and, therefore, palm more tolerant to fertilizer discounts. On the other hand, palm planted on the terraces, which are at a high risk of fertilizer leaching out and poor soil cation of subsoil, would be more sensitive to fertilizer discounts. Fertilizer discount, of course, would reduce the nutrient supply to the palm accordingly and consequently to FFB production for two to three years forward, therefore it was suggested to cut off the less response of specific nutrients only if possible.