Investigations on the nutritional status of <em>Hevea brasiliensis</em> plantations in the humid forest zone of CameroonPart 1: Micronutrient status and distribution in soils

Abstract

Micronutrients are very essential for plant growth. To make statements about the optimum micronutrient supply for Hevea brasiliensis, the micronutrient concentrations of selected soils in Cameroon under Hevea brasiliensis cultivation were studied. A total of 130 soil samples from plantations were collected and analyzed for their AAAc-EDTA-extractable micronutrient concentrations, pH and soil organic carbon. 62% of the sampled sites were deficient in extractable Zn, 15% in extractable Fe and 10% in extractable Cu. This shows that one main focus should be on a sufficient Zn-nutrition. AAAC-EDTA-extractable concentrations of Mn, Fe, Cu and Zn in the soils varied from 0.3 to 128, 14 to 235, 0.49 to 24 and from 0.3 to 12 mg/kg. Considering their mean values, the order of abundance of the micronutrients was Fe > Mn > Cu > Zn. Simple correlation analysis revealed that the AAAc-EDTA-extractable Cu- and Fe-amounts are significantly and positively correlated with soil organic carbon. There also was a positive correlation between AAAc-EDTA-extractable Cu, Mn and Zn with the pH-value of the soil and between Zn and Cu and Fe.

Keywords

• Micronutrients
• Hevea brasiliensis
• organic carbon
• pH
• AAAc-EDTA-extraction
• plant nutrition