Root turnover may contribute a significant proportion of recycled nutrients in agroforestry systems and competition between trees and crops for nutrients and water may depend on temporal fine root regrowth patterns. Fine root biomass (≤ 2 mm) and fine root productivity were measured during one year in plantations of cacao (Theobroma cacao) shaded by Erythrina poeppigiana or Cordia alliodora planted on a deep alluvial soil in Turrialba, Costa Rica. Fine root biomass of approximately 1.0 Mg ha− 1 varied little during the year with
