| dc.description.abstract | In the face of low and declining common bean yields in Uganda, past research has focused on crop
improvement and crop protection against pest and diseases. Little has been done to understand the
limitations from soil factors due to the widely held opinion that they are leguminous and can fix
their own nitrogen to overcome challenges from low soil fertility. A survey was conducted on 25
bean farmer gardens in Kitooke village, Gayaza sub county Kyankwanzi district. The specific
objectives of this study therefore were to assess the variation in soil chemical properties (available
P total N, exchangeable bases and soil pH) across bean field types and assess the variation in bean
yield across bean field types in Kitooke village, Kyankwanzi District. Soil samples were collected.
The soil samples were analyzed for total N, available P, exchangeable K, Na and Ca, OM, pH and
Texture using standard laboratory procedures. The bean fields were monitored to enumerate the
growing conditions of the crop. Four quadrats were established diagonally in each garden to
estimate the total plant population. The total number of plants were counted and recorded per
quadrant. In each quadrat, three plants were selected randomly during harvest and number of pods
and number of seeds per pod were counted, weighed on a sensitive digital scale and data recorded
separately. Soil analysis data were subjected to correlation analysis to identify uncorrelated soil
properties, which were then subjected to principal component analysis and hierarchical clustering
to generate a dendogram whose clusters were used to test the hypothesis about effect of soil
properties on bean yields in Kyankwanzi District. PC1 accounted for 36.7% while PC2 accounted
for 33.2% of the observed variation of the surveyed bean fields the loadings of the PC1 showed
that exchangeable potassium and total nitrogen were the most influential soil characteristics
explaining the variability in surveyed bean fields, which were grouped into 2 clusters in the
dendogram based on the selected soil characteristics. Cluster 1 had more fertile soils with respect
to K and N compared to Cluster 2. Cluster 1 had higher bean yield than cluster 2 by 170kg per ha.
This difference was due to higher number of pods per plant and higher seed yield per plant in
Cluster 1 compared to Cluster 2. It was concluded that higher soil fertility can enhance common
bean yield in Kitooke village, Kyankwanzi village, despite the common notion that being
leguminous, common beans can fix their own N and therefore perform well on low fertility soils. It
was recommended that nutrient omission trials be conducted in the study area to identify and
quantify the inherent soil supply of the most limiting nutrient to common bean production.
Keywords: Available phosphorus, Exchangeable potassium, Soil pH, Total nitrogen, Uganda. | en_US |
