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The use of Enriched organic fertilizer to Reduce organic and Inorganic Fertilizer Application and Increase the Potato Yields in the Highlands of Indonesia. Experiment was conducted at Experimental Station of Indonesian Vegetable Research Institute (the elevation of this site is 1250 meters above sea level) from June to November 2017. The objective of the experiment is to obtain an efficient technology of nutrient management in terms of organics and biological fertilizers and to obtain appropriate technology of potato tuber. The implementation of the research was preceded by making compost manure using Bio-decomposer for one month and enriched by using Bio-Phosphate and beneficial Micro-organism, dolomite, ash husk and rock phosphate, then continued with its application in the field with potato as an indicator plant. The treatments were arrange in a randomized complete block design (RCBD) with four replications. The treatments included the use of organic fertilizer in terms of horse manure enrichment at a rate of 20 and 40 t/ha and inorganic fertilizer at a rate of 0, 500 and 1000 kg NPK and horse manure 40 t/ha + 1000 kg NPK/ha as control plants (farmer’s practice). Results of the experiments indicated that the use of horse manure enriched by microorganism can reduce a rate of horse manure from 40 ton/ha to 20 t/ha to produce growth and yield of potato. Enriched horse manure can also reduce the use of inorganic fertilizers by half rate (500 kg NPK / ha). Combination of enriched horse manure 20 t / ha + 500 kg NPK / ha is more efficient to increase yield of potato tubers. The use of enriched horse manure does not seem to affect the improvement of soil fertility, especially for the availability of soil P and soil biological activity.
Keywords: Solanum tuberosum, horse manure, decomposer microbes, inorganic fertilizers, tuber yields.