Nutrient dynamics and sustainability of short rotation Eucalyptus camaldulensis plantations in southern India

Though awareness of fertilizer application has increased over time, low nutrient use efficiency is still a major limiting factor for eucalyptus plantations in India. A study was carried out to understand the nutrient dynamics under different soil fertility conditions by omission of macro nutrients (alone or in combination) and its comparison with balanced nutrient application (NPK) in short rotation Eucalyptus camaldulensis in southern India. This study revealed two phases of nutrient accumulation. The juvenile phase was characterised by an increase in nutrient uptake till canopy closure followed by a phase when the nutrient demand declined. The nutrient partitioning in different tree components changed with age. The rate of accumulation of N and K decreased in the order: leaves > bark > branches > wood > underground parts. The rate of accumulation of P, Ca and Mg decreased in the order: bark > leaves > branches > underground parts > wood. Balanced nutrient application gave 79% higher wood yield than control (no nutrient supply). This study conceptually and quantitatively compares the soil fertility regimes and explores the effect of nutrient limitation at the plant and plant-soil-level. Study also highlights the role of efficient nutrient management for sustainability of plantations, and ways to maximize yield, and improve soil nutrient balance at harvest.