Litterfall Productivity, Decomposition Rate, And Nutrient Release of Anthocephalus cadamba Miq

Abstract

Maintaining the nutrient supply in soil is crucial for sustaining productivity. Nutrient cycling in ecosystem provide available nutrient through inputs, storage pools, and outputs. In nutrient cycle, plant nutrient uptake from soil and return to soil from litterfall, coverground species, and remain harvest plant through decomposition process. Jabon putih (Anthocephalus cadamba Miq.) is one of Indonesia native species which has high prospect for plantation forest and revegetation in degraded ecosystem, such caused by mining operations. The soil of overburden dumps in coal mining are physically, nutritionally and biologically poor. This study was conducted to calculate productivity, decomposition rate, nutrient content and nutrient release to 4-year-old jabon plantation, also to test the application of jabon compost that applied to jabon seedling with soil from coal mine as planting media. Research was conducted at 4-year-old jabon plantation. Method of Litterfall productivity use litterfall collection traps every week during 12 weeks. Decomposition rate was used litter bag technique, with 120 of bags which placed above soil floor. Collecting data for use application of jabon compost was held during10 weeks. Total productivity during 12-week is 22.25 g m-2 week-1 or 11.57 ton ha-1 yr-1. Rate decay constant (k) is 0.09 week-1 and relative decomposition rate was 0.086 g g-1 week-1. Nutrient input from leaf litter, from highest to lowest, in the following order: Ca (238 kg ha-1 )> N (230 kg ha-1)> Mg (151 kg ha-1)> K (110 kg ha-1)> P (44 kg ha-1). Magnesium has the highest percentage of nutrient release that is 98.11 % during 12-week decomposition. Application of jabon compost to soil from coal mine has significant effects on height and diameter growth, total biomass, and shoot and root biomass, but it did not significantly effected on shoot-root ratio. Combination between media and 30 % jabon compost increased plant height by 69 %, diameter by 72 %, and biomass total by 193 % compared with control treatment.