Efektivitas Pupuk Majemuk Dan Asam Humat Pada Budidaya Kentang Di Kabupaten Gowa Sulawesi Selatanfadjry Djufry

Effectiveness of Compond Fertilizer and Humid Acid in Potato Cultivation in the Gowa District, South Sulawesi. The organic fertilizer recommendation for potato cultivation ranged 10-30 t/ha. This dose is too high, because the farmers has to bear high cost for other agroinput and labor. Application of humic acid (HA) is one alternative that can replace the function of organic fertilizer. When it is compared to organic manure, HA is faster in fertilizing the soil 10 times or 200 times more efficient than that of manure (50 kg of HA is equivalent to 10 t ha of manure). The use of HA is expected to increase the efficiency use of NPK 25-50%. This study aimed to determine proper doses of Super NPK fertilizer and HA that gave the highest growth and yield of potatoes. The experiment was conducted in the Village Pattapang, District Tinggi Moncong, Gowa regency, South Sulawesi, at an altitude of 1,100 m above sea level on June through December 2011. The research used split plot design with three replications. The main plot consisted three levels of NPK Super, i.e. 300 kg/ha, 450 kg/ha and 600 kg/ha. Subplot HA comprised three levels that were 0, 0.75%, and 1.5%. The results showed that the application of various doses and percentages of Super NPK and HA had no effect on plant height, but it did with the width of the canopy and the production of potato plants. Highest potato production obtained in Super NPK fertilization 300 kg / ha and HA 1.5% (16.47 t/ha). Application of HA on the potato crop fertilization was able to save of NPK fertilizer up to 50%. Application of Super NPK at 300 kg/ha + 1.5% HA was able to give a profit of Rp73.481.339/ha with the RC ratio of 2.75