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 which was created by omission of macro nutrients (alone or in combination) and its comparison with balanced nutrient application (NPK). This study reveals two phases of nutrient accumulation. First, juvenile phase which 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 order of Leaves > Bark >Branches > Wood > Underground parts. For P, Ca & Mg the rate of accumulation decreased in the order - Bark > Leaves >Branch>Underground parts > Wood. Balanced application of nutrients produced 44 per cent higher wood yield than trees grown on indigenous soil nutrient (-NPK) supply. This study conceptually and quantitatively compares the wide range of soil fertility regimes and explore the limitation of nutrients on plant and plant-soil-level. It explains the importance of efficient nutrient management for sustainability of plantations and ways to maximizing yield and improving soil nutrient balances at harvest.