| dc.description.abstract | Micronutrients are essential for growth of
plants and although they are required in
small quantities, inadequate supply of one
or more of these results in reduced yields
and quality of crop products. Micronutrients
are transferred through the food
chain to human beings and are important
for health, growth and development. Deficiency
of these poses a threat to the social-economic
development of a nation due
to the associated effects which include increased
mortality rate, impaired physical
and cognitive development and reduced
labor productivity. In the 2011 national
food and nutrition security policy, it was
reported that due to inadequacy of food
quality and diversity in the regular diet
among Kenyans, over 10 million people
suffer from chronic food insecurity and
poor nutrition. There is therefore need to
carry out research on the levels of micronutrients
in food crops and this would be
helpful in the establishment of plant quality
monitoring systems as well as micronutrient
bank and management systems
in Kenya so as to monitor plant health
and thus come up with possible interventions.
The study was aimed at finding out
crop response to micronutrients available
in the soils on which they were grown and
comparing the micronutrient levels among
different food crop species. Leaves/whole
plant of beans (Phaseolus vulgaris), potatoes
(Solanum tuberosum) and maize (Zea
mays) were sampled from Muguga, Kenya,
following an offset grid sampling pattern
in which plots of 100*100 m were
marked out and samples randomly collected
within a radius of 3 meters from
the grid intersection and composited. All
the samples were analyzed for micronutrients
(Mn, Fe, Ni, Cu and Zn) by Total reflection
X-ray Fluorescence (TXRF). The
mean concentration for Mn in beans, potatoes
and maize were 215.594, 168.876 and
177.756 respectively. For Fe, the means
were 750.262, 553.318 and 917.031 respectively.
The means for Ni were 2.354,
1.342 and 0.788 respectively while Cu had
means of 9.374, 11.914 and 10.082 respectively.
Zn showed means of 65.852,
40.045 and 67.393 respectively (all concentration
levels are in units of mg/kg).
The results did not show deficiency among
the micronutrients in all the food crops analyzed.
However, following the coefficients
of variation (CVs) the concentrations of
Mn and Fe varied significantly between the
crops while Ni, Cu and Zn showed no significant
variation. Each plant takes up the
available nutrients differently and this research
showed that beans had the best response
to available nutrients with a correlation
of 0.9424. More research is to be
conducted in other parts of the country
for sufficient and conclusive micronutrient
mapping. | en_US |
