TY  - JOUR
T1  - Lunnyu Soils in the Lake Victoria Basin of Uganda:Link to Toposequence and Soil Type
AU - , P. Nkedi-Kizza AU - , B. Vanlauwe AU - , M.M. Tenywa AU - , S. Grunwald AU - Fungo, B. 
JO  - Online Journal of Earth Sciences
VL  - 4
IS  - 2
SP  - 63
EP  - 71
PY  - 2010
DA  - 2001/08/19
SN  - 1991-7708
DO  - ojesci.2010.63.71
UR  - https://makhillpublications.co/view-article.php?doi=ojesci.2010.63.71
KW  - pedological properties
KW  -soil type
KW  -toposequence
KW  -Lunnyu soil
KW  -remedy
KW  -Uganda
AB  - Lunnyu as described by farmers is a rare form of soil infertility, especially in the lake Victoria Basin of Uganda. Neither the cause nor the remedy to this soil type is not known. We compared the physical-chemical characteristics of Lunnyu soils using soil type and slope position in order to explain their variability in the lake Victoria Basin of Uganda. At landscape level, 6 existing Lunnyu patches located on 4 different soil types (<I>Chromic lixisol</I>, <I>Mollic gleysols</I> and <I>Plinthic Ferralsols</I>) were identified at a scale of 1:250,000. At each Lunnyu patch, the slope was divided into 3 parts; shoulder, back-slope and foot-slope. About 5 locations along the contour of each landscape position and at distance of between 20-30 m were located and soil samples taken at 2 depths (0-20 and 20-40 cm). The soil samples were analysed for pH, available P, texture and exchangeable bases. Results show that Lunnyu patches on <I>Chromic lixisol</I> and <I>Mollic gleysols</I> had higher pH, P, sand, clay and silt compared to those on <I>Plinthic ferralsols</I> and <I>Petrifferic lixisol</I>. Neither of the soil properties was influenced by landscape position. Soil pH, Ca, Mg and K were higher in topsoil compared to subsoil. Neither slope position nor the type of Lunnyu has showed consistent differences in all the soil properties. Thus, the hypothesis that Lunnyu soils are an erosional phase, occurring characteristically at the backsolpe positions of the toposequence, according to this study does not hold. However, results suggest a pedological explanation in which pH and texture could influence occurrence of the Lunnyu soils. We recommend further studies of the pedological properties of the soils and other trace elements that this study has not investigated.
ER  -