| dc.description.abstract | The total copper content was determined in river
water, sediments, soil, potato shoots and tubers,
weeds, coach grass, coffee leaves and coffee berries
using atomic absorption spectrophotometry (AAS).
Plant available copper in the soil was also determined
using AAS and the values obtained compared with the
copper content in coach grass. coffee leaves and
coffee berries. Also compared was the total copper
and the EDTA extractable copper (plantavailable Cu)
content in the soil.
The variation oftotal copper content in the
soil with time. depth and rainfall was studied. This
study was done in a garden where a known quantity of a
copper based fungicide had been sprayed on the soil
surface.
The values obtained in river water showed no
significant poLlut.Lon and the same was true of the
potatoes analysed.
AAS was chosen for all analysis due to its
convenience both "timewiseand economically. Analysis
of certified samples proved the AAS technique to be
accurate.
Soils from Kirinyaga District had ahigher copper content than those from Kiambu District. Soils
from Kirinyaga had copper levels ranging between 25
ppm and 527 ppm while those from Kiambu had levels
ranging between 9ppm and 140 ppm. Plant available
copper content was found to be proportional to the
total copper content in the soil. River water from
the two regions had a low copper content ranging
between 4 parts per billion and 20 parts per billion.
For potatoes. the peels had a higher
copper content than any other tissue. Inthe case of
coffee leaves and beans, leaves had a higher copper
level than the beans. Generally for plants, the
copper content ranged-between 2 parts per million and
200 parts per million. | en |
