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Recent Submissions
SOIL MOISTURE CONSERVATION, CROPPING SYSTEMS AND SOIL FERTILITY EFFECTS ON SOIL AND MAIZE PERFORMANCE IN MACHAKOS COUNTY, KENYA
(2019-05) NGIE MWENDE
The main causes of food insecurity in semi–arid parts of Kenya are low soil
fertility, low and unreliable rainfall. These two causes are the main challenges facing
small-scale farmers in food production especially in semi-arid areas of the country.
To overcome these challenges, soil and water management technologies especially
those in soil and water conservation need to be embraced. The aim of the study was
to determine the effect of tied ridges, fertilizers and cropping systems on soil
properties (moisture, pH and organic carbon), growth and yield parameters of maize;
and to identify the most cost effective water and soil management technology. This
study was carried out in four seasons at Katumani in Machakos County. The
experiment was a 2 x 4 x 2 factorial, laid out in a randomized complete block design
(RCBD). The treatments were: tied ridging, flat bed planting, farm yard manure 0
t/ha, farm yard manure 5 t/ha, nitrogen fertilizer 20 kg/ha, farm yard manure 5 t/ha +
nitrogen fertilizer 20 kg/ha, maize mono crop and maize cowpea intercrop. Data
collected included soil moisture content, soil pH, total organic carbon, growth
parameters and maize yield. The results showed that, treatments with flat bed
planting in maize mono crop significantly increased soil moisture content at 0–20cm
depth as compared to tied ridging in maize cowpeas intercrop during short rains
2015. Application of farm yard manure at 5 t/ha increased soil moisture content at 2
and 4 weeks after planting. The soil moisture content ranged from 6.30% to 23.80%.
During the short rains 2015, maize mono crop significantly increased vegetative
growth in comparison to maize cowpeas intercrop. Treatment with flat bed and 20
kg N/ha in maize mono crop had the highest mean for vegetative growth. However,
during the long rains 2016, treatment with tied ridging and 20 kg N/ha in maize
mono crop registered the highest mean for vegetative growth. During the short rains
2015, treatments with maize mono crop significantly increased grain yield with a
range of 1.35 t/ha 3.59 t/ha. Flat bed planting with farm yard manure 5 t/ha in maize
cowpea intercrop significantly increased the grain yield by 165.93%. The harvest
index during the short rains 2015 ranged between 0.35 and 0.48. Treatments with
maize mono crop significantly increased gross benefit, net profit, gross margin and
cost benefit ratio during short rains 2015 and long rains 2016. Application of farm
yard manure 5 t/ha + 20 kg N/ha had the highest variable cost. The cost benefit ratio
was positive during the short rains 2015 with a range of 1.47–2.98. The yield
differences among the four seasons could have been as a result of
variations/distribution in rainfall amount, soil moisture content and soil fertility as
induced by the treatments. Flat bed planting increased the yields during the short
rains 2015 when the amount of rainfall was high whereas tied ridging resulted in
improved yields during short rains 2014, long rains 2015 and 2016 when rainfall
amount was low. For the farmers to maximize yields and profits in the study area,
adoption of flat bed planting with farm yard manure 5 t/ha and maize cowpeas
intercrop during the seasons of high rainfall could be appropriate treatment
combination according to the findings of this study. However, during seasons with
low rainfall, tied ridging with 20 kg N/ha and maize mono crop could be
recommended for adoption. Also, variations in seasonal rainfall should be
considered when integrating different soil and water management practices because
the effectiveness of different technologies vary with the seasons. Farmers in
Machakos County may have to consider use of supplementary irrigation during the
dry spells to increase soil moisture.
UTILIZATION OF RAINWATER HARVESTING TECHNOLOGIES AMONG SMALLHOLDER FARMERS IN MURANG’A COUNTY, KENYA
(2024-08) FRANCIS IRUNGU ITEMO
Water is a critical resource in environmental sustainability, agricultural production as
well as for improved livelihoods. Climate variability hinders crop and livestock
production in Sub-Saharan African countries. Rainwater harvesting (RWH) is a climate
smart agricultural practice to revert this. Rainwater harvesting has been practiced among
smallholder farmers for centuries in many parts of the world. Recently, it has gained
more attention due to the reported increasing water demand and the need for sustainable
water management hence the research was conducted to evaluate the utilization of
rainwater harvesting technologies (RWHTs) as a climate smart agricultural practice in
Murang’a County, Kenya. Drawing on data from a cross sectional survey of 384
households, our research evaluated the adoption of RWHTs, intensity of crop and
livestock enterprises adoption under RWHTs and the determinants for RWH among
smallholder farmers in Murang’a County, Kenya. Multistage random sampling and
proportionate to size technique was employed to sample farmers in three wards namely:
Murarandia, Mugoiri and Wangu. The KOBO kit a phone application was used during
data collection. To assess the adoption of RWHTs, descriptive statistics and analysis of
variance (ANOVA) were applied. The results found that rooftop water harvesting
technology (93a ± 22), infiltration pits (81a
± 21), furrows (68a ± 16), deep ploughing (67a
± 21), terraces (54a ± 14), mulching (51a ± 17), retention ditches (23a ± 18) and water pans
(17a ± 5) water harvesting technologies had statitistical significant differences among
smallholder farmers (P<0.05), while negarims, water bunds and dams water harvesting
technologies were not statistically significant (P<0.05) adopted at a mean ± S.D of 11 ±
4, 6 ± 2 and, 1 ± 1 smallholder farmers, respectively. The findings exhibited that
households that practiced livestock production including: dairy cattle farming, goat
rearing, sheep farming, beef cattle rearing, pig production, and poultry farming, watered
their livestock using rooftop harvested rainwater at a rate of 12%, 10%, 9%, 6%, 3% and
5%, respectively while, 1% practiced aquaculture. Multivariate probit model (MVP)
analysis showed that crop enterprises adopted (macadamia, maize, coffee, tea, avocado,
fodder, arrowroots, beans, bananas, mangoes and sweet potatoes) among household heads
were key crop enterprises that influenced adoption of these RWHTs. The MVP model
also pointed out that household head’s access to credit facilities, landownership, age,
level of income, education level, gender, family size, source of income, membership to
farmers’ groups and access to training services were statistical significant (P<0.05) thus,
influenced RWH adoption. Membership to farmers group had merits including: support
in farmers’ training, social ties, source of information and source of credit which were
also key determinants to RWH adoption. The study recommends relevant stakeholders
and policy makers to consider promotion or up scaling of RWHTs for crop and livestock
enterprises among household heads in consideration of the determinants influencing
adoption rate in Murang’a County.
PROCUREMENT PRACTICES INFLUENCING SERVICE DELIVERY: A CASE OF KENYA POWER
(European Centre for Research Training and Development UK, 2014-12) Maurice James Davis
In developing countries, public procurement is increasingly recognized as
essential in service delivery and it accounts for huge proportion of total expenditures.
However, there is a growing recognition that, despite significant increases in resource, public
service delivery is falling in many developing countries. Poor service delivery of electricity can
be justified by ineffective procurement systems within an organization. The purpose of this
study is to evaluate procurement practices influencing service delivery in the public sector with
focus on the provision of electricity: A case study of Kenya Power. The study is based on the
socio-economic and institutional theories. The objectives of the study; to establish the influence
of procurement policy on service delivery, to evaluate how procurement planning influence
service delivery, and to evaluate sustainable procurement practices influence on service
delivery. Methodology used in the study is a case study with a focus on Kenya power. Stratified
sampling technique was used to select a representative sample from a target population of 160
employees with a sample size of 100 respondents. The respond rate is 71%. A mixture of
Interview and Likert- Scale questionnaire were employed. The collected data was further
analyzed using SPSS and excel computer software as well as descriptive statistics. The findings
revealed that: Procurement rule and regulation lack flexibility and it is hampering the
procurements operations as revealed by 77.5%; Procurement planning does not take long term
cost of ownership into consideration as also revealed by 39.4%; the findings also revealed
59.1% agreed that there is no Sustainable procurement practice by the company even though
it has Green policy in places but, the implementation is hampered by organizational culture as
well as budgetary constraint. The followings are major Recommendations: The National
procurement policy or rules and regulations should be review to put into place clauses that
will lead to flexibility and inclusion of emerging trends in the procurement process as
procurement is an involving profession; The top management should ensure that the
procurement departments are involved in all procurement and contract related activities as a
result of the decentralize nature of the company’s procurement system; The planning process
for electricity expansion should involve all concern departments so that planning can be done
in advance before budgets are approved; Government should increase it subsidy to the
company’s operation; The company should include sustainable procurement criteria within its
procurement and contracting decisions.
DESIGN AND CONSTRUCTION OF A MICROCONTROLLERBASED FIVE DEGREE OF FREEDOM ROBOTIC ARM USING SERVO MOTORS
(2018-08) NICHOLUS KARIUKI NDWIGA
Integration of robotic arms into working tasks has currently increased magnificently in
performing the very repetitive, dangerous or difficult tasks. Typically, a robotic arm is a
mechanical arm that is programmable to mimic the behavior of a human arm in terms of
how it functions. Computers and microcontrollers have widely been used in the control
of robotic arms with the help of sensors, levers, buttons, wireless devices, just to
mention but a few. More advanced technology has lately revolutionized their control,
ranging from the haptic technology using accelerometers to human-brain control
through noninvasive technology. One of the areas robotic arms are used in our day to
day life is in land movers like in excavators, bulldozers, backhoes, front loaders and
trenching machines. The available arms for these devices need personnel throughout
their operations to control and manipulate their movements using gears, levers, pistons,
pedals and sometimes buttons. There is a great need to complement their movement so
that they can autonomously operate once they are powered. This research focused on
the design, implementation and control of a robotic arm with five degree of freedom
(DOF) using servo motors. It was designed to entirely operate by itself in a repetitive
routine. A control circuit based on a PIC18F4550 microcontroller interfaced with a
servo motor was built and a suitable software for the control of the rotation of motor
developed. The control circuit was used to send appropriate Pulse Width Modulation
(PWM) signals to different motors to produce the desired rotation. In this study five
servo motors were employed to realize the robotic arm. Three servos were utilized to
control the body motion including base, shoulder, and elbow and two servos were used
for the motion of end effector, the wrist and the gripper. The software for the control of
rotation of the motors was done using C programming language. The codes were
developed and debugged using the mikroC PRO for PIC Integrated Development
Environment (IDE). PICkit™3 in-circuit programming module was used to upload the
program to the microcontroller through PICkit™3 programmer software. The materials
were assembled and joined to construct the robotic arm which was tested in the
University laboratory to demonstrate repetitive picking, lifting and dropping of objects
of specific weight from one place to another without the influence of the operator.
SYNTHESIS AND CHARACTERIZATION OF NIOBIUM PENTOXIDE THIN FILMS PREPARED BY SPRAY PYROLYSIS TECHNIQUE FOR DYE SENSITIZED SOLAR CELL APPLICATION
(2019-03) KINEENE MIRIAM MWONGELI
There is a rapid increase in demand for energy worldwide and one of the most
promising approaches to resolve this crisis is through use of photovoltaic
technologies. Dye sensitized solar cells (DSSC) are attractive candidates in this
regard. This is because the materials they use are of low cost and non-toxic.
Niobium pentoxide (Nb2O5) thin films have been stable as photo anode for DSSC.
Methods that are used to deposit niobium pentoxide thin films include hydrothermal
method, solgel method, anodization technique, electro-deposition, sputtering, and
spray pyrolysis. Among the above mentioned methods, spray pyrolysis is the
simplest. It is a low cost method especially with regard to equipment. The technique
requires chemicals that can undergo pyrolysis. In this study, Niobium pentoxide
(Nb2O5) thin films for DSSC application were deposited on ordinary glass substrates
using the spray pyrolysis technique. In the synthesis of Nb2O5, Niobium
pentachloride (NbCl5) was used a precursor solution. This was prepared by
dissolving Niobium pentachloride in distilled water to which hydrogen peroxide and
acetic acid were added. The deposition parameters of the niobium thin films such as
spray duration and substrate temperature were varied. The sprayed solution
underwent thermal decomposition resulting in formation of niobium pentoxide
(Nb2O5) thin films. The optical characteristics of the films were determined using
the Shimadzu model DUV 3700 spectrophotometer. From the transmittance spectra
obtained, it was clear that the films were 60% to 90% transparent in the visible
region and the absorption edge occurred at around 300nm. Sheet resistivity of the
films determined by use of the four point probe method was 10-4Ωcm. XRD studies
revealed that the films were tetragonal in nature with well defined reflections at
(211) and (220). The average crystallite size was estimated to be 21.25nm. The
thicknesses of the films were determined using the KLA Tencor Alpha–step IQ
surface profiler and was found to range between 162nm and 517nm. Band gap
energy and absorption coefficient were estimated using point-wise unconstrained
minimization approach (PUMA) software. Band gap energy values ranged between
3.92 eV to 4.12 eV. From the obtained results, the films considered best for DSSC
application were those deposited at substrate temperature of 470oC and at duration
of 2 minutes.
