Pemodelan keseimbangan hara kaitannya dengan produksi tanaman kelapa sawit (Elaeis guineensis Jacq)

Abstract

Indonesia is the country which has the largest area of oil palm plantation in the world. Indonesia had only about 1.12 million hectares of oil palm plantation in 1990s, but greatly increased in 2000s which attain 4.15 million hectares and in 2012 had reached about 9.07 million hectares. Oil palm has many advantages compared to other oil crops such as higher production per unit area, long economic life, and its product, either edible or nonedible one can be used in variety industries. Oil palm productivity is highly affected by so many internal and external factors. Fertilization is one of the external factors which have a big effect on oil palm productivity. Nutritients addition through fertilization will lead of alter nutrient balance in the soil; which will affect nutrients availability and plant nutrient uptake. The aim of this study was to determine the nutrients balance for oil palm both of in the plant tissue and the soil. Hopefully, the results of the study could be use on of consideration in fertilizer recommendation practice related to determination of fertilizer requirements for oil palm thus will be more appropriate in order to achieve optimum oil palm productivity. Exploration survey method was used in this study by collecting data of oil palm production, foliar and soil analysis. The data were collected from several oil palm plantations in Indonesia such as North Sumatera, Jambi, Riau, West Sumatera, Lampung, South Sumatera, West Java, West Kalimantan, East Kalimantan, and South Kalimantan provinces. Diagnosis and Recommendation Integrated System (DRIS) was used for determined nutrients balance in the oil palm tissue whereas boundary line method was used for determining nutrients balance in the soil. The results showed that (1) the norms value for each nutrient ratio were 15.92 for N/P, 2.53 for N/K, 3.87 for N/Ca, 10.12 for N/Mg, 6.35 for K/P, 4.17 for Ca/P, 1.62 for Mg/P, 1.55 for K/Ca, 4.05 for K/Mg, and 2.65 for Ca/Mg; and (2) the optimum value of soil nutrient balance of Ca/K, Ca/Mg, and Mg/K were 6.4, 2.5, and 2.3 respectively.