Authors:B.Mohankumar and B.N.Divakara
Abstract:Root distribution pattern and competitiveness of bamboo (Bambusa arundinacea (Retz.)Willd.) for below ground resources in mixed speciessystems were evaluated using logarithmic spiral trenching and 32P soil injection techniques respectively. Excavation studies indicated that rooting intensityin differentsoil horizonsdeclined either exponentiallyor quadraticallywith increasing lateral distance from the bamboo clump. Surface horizon (0–10 cm) of the soil pro le showed the least bamboo rooting intensity. It was highest in the 10–20 cm soil layer with nearly 27% of the total roots. Clump size is another important determinant of bamboo rooting intensity. Smaller bamboo crowns/ clumpsshowed the lowest rooting intensity,when measured at 5 m and 7.5 m lateral distances and increased linearly with increasing crown radius. Implicit in this is the potential for anagement practices to regulate competition in mixed species systems through controlling clump size/ crown expansion. Our results also showed that 32P uptake by bamboo in binary combinationsinvolving teak (Tectona grandis) and vateria (Vateria indica) was proportional to bamboo rooting intensity, when the 32P label was applied to the dicot trees. Root competitiveness in polyculturalsystems involving bamboo, therefore, is a function of the proximity of bamboo to the associated tree/crop, which in turn, decidesthe bamboo rooting intensity.
Keywords:Rooting intensity; Tectona grandis