Soil Biochemical Properties and Nutrient Leaching from Smallholder Oil Palm Plantations, Sumatra-Indonesia

The study aimed to assess soil biochemical properties and nutrient leaching in palm oil plantation. The research was conducted in smallholder oil palm plantations which were located in Jambi Province - Indonesia. Nutrient leaching was determined by measuring nutrient concentration in soil solution bi-weekly and monthly in the frond stacked and fertilized areas; soil water samples were collected by using suction cup lysimeter. The result showed that the application of mineral fertilizer (e.g. NPK) and dolomite resulted higher base saturation, exchangeable Ca, and available P in the fertilized than frond stacked and inter row areas (p ≤ 0.05). Stacking palm oil frond increased the soil macro-porosity, hence decreased leaching of K, Mg, Na, P, and total Al in the frond stacked than in the fertilized areas. The lower leaching losses and the higher soil macroporosity in the frond stacked than in the fertilized areas indicated that either the water did not dilute nutrient in the soil due to bypass flow, or the nutrient release from mineralization did not surpass nutrient demand which is quickly uptaken by palm root. Proper soil management through synchronizing rate of fertilizer application with nutrient output or frequency of fertilizer application may potentially minimize leaching losses.