Alternative Methods for Handling Iron (Fe) Deficiency of Oil Palms (Elaeis guineensis Jacq.) Grown in Sandy Soil

Abstract

Iron (Fe) deficiency is one of the general problems that occur in Oil Palms (Elaeis guineensis Jacq.) which are planted on sandy soil. Fe is an important micronutrient in enzyme activities, including cytochromes in the process of electron transfer, chlorophyll synthesis, and in maintaining the chloroplast structure. The research was conducted in 2 series of field observations. The first observation was conducted on the application of clay mineral soils (Plinthic Kanhapludults and Lithic Dystrudepts) in a silt pit, while the second observation was on the application of liquid nano-sized Fe fertilizer through root infusion and trunk injection methods, in addition, Fe chelated fertilizer application were also observed. The observation variable was the level of Fe in leaves 17th. The results showed all treatments significantly increased levels of Fe in leaves with different plant response rates. Root infusion treatment shows a faster response than clay mineral soil treatment, namely at 2 - 4 months after application (50.3 ppm and 38.2 ppm). Meanwhile, clay mineral soil treatment has a slower plant response rate on increasing Fe level in the leaves with a significant difference against the control, precisely at 24 months after application. Normally, regular Fe fertilization is enough to fulfill plant nutrient needs. Application of Fe through trunk injection or root infusion can be an alternative treatment for short-term use, whereas the application of clay mineral (iron-rich) soil can be optional for long-term needs.