ABSTRACT
xii
The aim of the present study is to contribute to the
elaboration of a plan for sustainable land management of PHP, through the
mapping of actual and potential suitability for the cultivation of pineapple
with the help of a GIS. The framework for land evaluation of the FAO (1976) was
used to determine the land suitability. A reference system was established
using the software MapInfo Professional 7.5 for the realization of thematic
maps.
Depending on to results obtained, total approximately area is
approximately 3,000 ha with ten land units determined in the form of
semi-detailed surveying level. Based on the French Classification system (CPCS,
1967), two soil classes where identified namely: Andosols and Brownish soils.
According to the parametric method, Climate characteristics of the PHP were
moderately suitable (S2) to marginally suitable (S3). The actual suitability
classes of the PHP land for the cultivation of pineapples are as follows: S3
(53.41 %) and S3/N (29.62 %) and N1 (4.91 %). While the potential suitability
classes are: S1-1 (48.18 %), S2 (32.03 %) and S3 (7.73 %). Unclassified land
(hills, shocks and buildings) represent 350.75 hectares or 12.06 % of the
entire study area.
Modelling allowed the mapping of actual and potential
suitability of the land in PHP, as well as the spatial distribution of yields
and decay of pineapple mainly due to attack by Phytophthora. These maps were
obtained by a combination of intrinsic and extrinsic characteristics of the
land required for evaluation and organized into independent thematic layers.
As a result, although the chemical fertility of Andosols is
recognized, some other land factors could strongly influence the global
suitability and can influence significantly crop yields. This is the case of
climate, topography (slope), handling (structure and texture), parasites and
diseases related to land (attack by Phytophthora) and appeared to be the main
factors controlling the variability and spatial distribution of crop yield.
Therefore, the study recommends among others to avoid using a single type of
fungicide, cultivate on sloping land along the contour.
Keywords: GIS, Land suitability
evaluation, thematic maps, pineapple, PHP, Andosols.
INTRODUCTION
1
1.1 Contexte et problématique
La culture de l'ananas à la PHP se pratique
essentiellement en rotation avec la banane. Cette culture a pour principal
objectif d'assainir les jachères des lots bananes. Le choix des terres
pour la culture de l'ananas se fait en fonction de la disponibilité et
de l'accessibilité des jachères des lots bananes. Cependant la
structure a observé des irrégularités et une
variabilité (baisse de rendements) des rendements de l'ananas sur les
différents lots déjà cultivés. Ces
irrégularités et cette variation qui se traduisent parfois par la
pourriture du coeur de l'ananas, peuvent être liées à
celles des conditions climatiques, pédologiques et ou à l'effet
des pratiques culturales. Or, la mise en valeur des terres de la P.H.P. pour
les cultures en général et pour la culture de l'ananas en
particulier se veut à la fois performante, durable et respectueuse de
l'environnement (ISO 14001 et Global Gap®).
La nécessité de connaître l'aptitude des
terres de la PHP pour la culture de l'ananas s'inscrit donc comme un outil
d'optimisation de la production qui tient compte de l'environnement et justifie
la conduite de la présente étude.
|