BITÖK
Bayreuther Institut für Terrestrische Ökosystemforschung
  Home Printable form Search fulltext Seite in deutsch Uni-Bayreuth
|  | Organisation |  | Research Publications |

Publications


>> internal Site (SSL)

Search:



 

Bergmann, C; Stuhrmann, M; Zech, W: Site factors, foliar nutrient levels and growth of Cordia alliodora plantations in the humid lowlands of Northern Costa Rica, Plant and Soil, 166, 193-202 (1994)
Abstract:
Within the perhumid, Atlantic lowlands of northern Costa Rica, Cordia alliodora plantations were studied in order to explain the observed pattern of growth irregularities. The soils, that were partly used as pastures over long periods, could be classified roughly into two units: (i) red, deeply weathered, slightly acidic soils from Mg-enriched parent material and (ii) brown, strongly acidic soils with high saturation of exchangeable A1 (up to 80%). Leaf analysis revealed that Cordia is a highly demanding species in respect to macronutrients. Poorly growing trees in slope position suffered from an insufficient supply of N and P. K/Mg ratios of chlorotic leaves are very low. Soil analysis showed that nutrient deficiencies were related to (i) insufficient soil nutrient reserves of the poor, tropical soils or (ii) to an inhibition of nutrient uptake by soil physical or chemical factors. All sites are characterized by very low K reserves and losses of nutrients that are organically bound (N, P) caused by erosion. In the Mg-rich red soils, low amounts of K lead to K/Mg imbalances. Soil compaction caused by cattle grazing occurs on both soil units. It negatively influences the root development of Cordia, and hence nutrient uptake. In the brown soils, high amounts of exchangeable A1 hinder a sufficient supply of nutrients (e.g. P) to the assimilation organs.
This site makes use of cookies More information