Publication JTAFS Issues Archive 1992 Volume 20 No.1 Root activity patterns of two coffee species ( coffea liberica and coffea robusta ) grown under different soil environments: a study using 32P tracer technique* Root activity patterns of two coffee species ( coffea liberica and coffea robusta ) grown under different soil environments: a study using 32P tracer technique*
K. C. Tham1, B. Kadmin2, P . Y. Yau3, W . M. Wan Othman4, K . Ambak5, C . C.Ting6 and Y.Ahmad7
Abstract
The root activity distribution of two coffee species viz. C. liberica and C. robusta grown in four locations viz. Serdang, Kluang, Pontian and Parit Botak covering six soil series viz. Bungor, Munchong, Rengam, Parit Botak, shallow and moderately deep peat was studied in eight experiments using radioactive 32P soil injection tracer technique. Although Liberica coffee trees have a wider spread of active surface feeder roots than Robusta coffee, their respective active root disribution within the crown area were similar when measured in relation to the spread of the tree crown. In both species, the average activity close !o the trunk (25-50 cm radius from trunk) was 3-4 times higher than those at the dripline. The surface feeder roots of young Liberica coffee nees had high root activiry within the 50 cm radius from the trunk, which declined progressively with age resulting in a wider spread of active feeder roots. In spite of the decline, activity remained highest within the 50 cm radius irrespective of age. The results were similar on both the peat and inland soils. Girth size of Liberica coffee had no significant effect on the active surface (10 cm depth) feeder root distribution. On Munchong series, almost all the active feeder roots of Robusta (95%) and Liberica (83%) coffee were distributed near the soil surface (5 cm). About 15% of. the root activity of Liberica coffee were distributed at the 50 cm depth. On the acid sulphate soil viz. Parit Botak series, almost all (96%) the active feeder roots of Liberica coffee were confined to the soil surface (5 cm depth). On peat, a deeper disribution of the active feeder roots was observed. To achieve greater fertilizer use efficiency, fertilizer should be applied closer to the trunk below the canopy.
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