Root biomass in a mature cacao (Theobroma cacao L.) plantation. In: Theobroma v. 11 p. 77-85, 1981.

Abstract

A quantitative analysis of the root biomass of an 11-yr cacao plantation is presented. Root biomass values are based on extraction of 100 soil samples of 120 cm3 each, from sail depths of 0 - 15 em. Root data from greater depths were interpolated from literature. AlI the samples were colIected and analyzed in November, 1980. The total cacao root biomass was estimated with 1038g m2 dry weight, or about 10 t ha. The rootlets had a mean dia meter of 0.22 mm and were localized to about 90% in the upper 10 cm of the soil. Calculation of the rootlet extension resulted in a value of 1200 m m- 2 , i.e. 12 x 10' km h. This rootlet extension represents about 1 m2 of absorbing root surface per m2 of soil surface. The high rootlet concentration in the upper 3 em of the soil indicates a mean distance of 2 - 3 mm between rootlets.