Accelerated nutrient cycling via leaf litter, and not root interaction, increases growth of Eucalyptus in mixed-species plantations with Leucaena

The admixed litter decomposition, rather than root interaction, is a primary contributor to E. camaldulensis growth in plantations with L. leucocephala in the valley-type savanna. The rocky soils in the savanna may block root overlapping by greatly inhibiting root extension of both tree species. The admixture of litters produces an increase in the supply and availability of soil nutrients that are returned to the E. camaldulensis rows via the admixed litters, due to the enhancement of the quantity, quality and decomposition rates of the leaf mixtures. These factors promote the growth of E. camaldulensis, and this effect may have implications for the necessity of litter management for Eucalyptus plantations in certain regions with arid climate and rocky soil.