Soil properties under baobab trees (Adansonia digitata L.) and their influence on fruit nutrient contents

B.Sc. Makuei Joseph Magai Awuol

Master's thesis

Abstract:

Baobab (Adansonia digitata L.) is a multipurpose tree whose leafs and fruit pulps are eaten by rural population in Africa to benefit from higher level of vitamin C than in orange and calcium than in cow milk. Several studies however reported high variation in concentration of chemical elements of the pulp, but the cause is not well attributed. The aim of this study was to determine the influence of soil properties on fruit nutrient content in Eastern and Coast provinces of Kenya. Data of baobab pulp nutrients were obtained from previous study of ICRAF, where 64 baobab trees were sampled using transect lines along Mombasa highway to collect socioeconomic data from baobab farmers in which major nutrients of the pulp were determined. In this study, soil samples under 63 baobabs were collected and analysed. The collected soil samples were analysed for pH using pH meter, C and N using NCS analyser flash 2000, plant available P using Olsen method, CEC using ISO 11260 titration of BaCl2 by NaOH and major cations (Al, Mn, Na, K, Mg, Zn etc.) were extracted from BaCl2 solution using ICP method. Principle component analysis (PCA) was used to determine correlation of pulp nutrient with soil chemical elements at different soil levels and also to correlate pulp nutrients for baobab from different geographic locations and to determine soil chemical composition and distribution across geographic location and within profile. The results from PCA showed that there was high correlation at all aspects explained at p<0.05 coefficient of correlation. Major soil chemical elements that were correlated to most pulp nutrients include soil pH, plant available P and P. This indicates that these elements were the limiting factors for baobab distribution and nutrient composition of its pulp.

Keywords

Baobab, nutrition, pH, pulp composition, soil properties

Language used: English

Date on which the thesis was submitted / produced: 24. 8. 2016

Thesis defence

• Supervisor: doc. Ing. Bohdan Lojka, Ph.D.
• Reader: Jan Hladký, externi

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme / field:
Tropical Agriculture / Tropical Crop Management and Ecology