9 Records out of 22207 Records

The adoption of low-cost low head drop irrigation in small-scale farms in Kenya.

Author: Kulecho, I K

Awarding University: Cranfield University, England

Level : PhD

Year: 2003

Holding Libraries: ;

Subject Terms: Agriculture/Agricultural economics/Irrigation/ ;

Abstract:

Using the theory of the adoption and diffusion of innovation, this research aimed to identify the factors affecting the rate of adoption and continued use of low-cost low head (LCLH) drip irrigation in Kenya. Following a review of experiences of low-cost drip irrigation from India and sub-Saharan African, primary information was obtained using informal interviews in a two-phase survey. A total of eighty-six respondents were interviewed in the two phases. Phase 1 examined the factors influencing the adoption of LCLH drip irrigation. The key respondents in phase 1 were irrigation farmers (drip and non-drip), government officials, irrigation industry representatives and staff of non-governmental organisations (NGOs). Phase 2 examined the factors affecting discontinuation of LCLH drip irrigation. In phase 2 only LCLH drip irrigation farmers and those who had discontinued using it were interviewed. While the low-cost medium head drip irrigation was the dominant irrigation in India, the low-cost low head drip irrigation, gravity fed and in a kit form, was found to be the most common system on smallholder farms in Kenya. The results showed that for the rate of appropriate low-cost drip irrigation uptake to increase in Kenya, it was important to remove political and institutional inhibiting factors dominant during the implementation stages of the innovation-decision process. It was necessary for farmers to have a need to save irrigation water, reliable irrigation water resources, effective water user organisations, efficient marketing facilities, efficient technical support services, relevant cultural background and good security for the kit. The LCLH drip irrigation kit appeared to have more maintenance problems than the alternative irrigation methods. Furthermore, government policies and extension services as well as irrigation industry efforts appeared limited. It appeared that the technology would most likely to be adopted where farmers have a reliable but limited (in volume) water supply

Erosion hazard assessment in the upper Ewaso Ng'iro Basin of Kenya : application of GIS, USLE and EUROSEM

Author: Mati, Bancy Mbura

Awarding University: Cranfield University, England

Level : PhD

Year: 1999

Holding Libraries: Kenya National Archives and Documentation Services Library ; World Agroforestry Centre Library ; Kenya Agricultural Research Institute Headquarters Library ; Institute of Commonwealth Studies Library ;

Subject Terms: Ewaso Ng'iro River ; Soil erosion ; Geographic information systems ; Scientific imaging ;

Abstract:

A methodology was developed for assessing soil erosion hazard in the Upper Ewaso Ng'iro basin of Kenya, using Geographic Information Systems (GIS), the Universal Soil Loss Equation (USLE) and the European Soil Erosion Model (EUROSEM). The USLE was used in a GIS environment by creating thematic maps of R, K, L, S, C and P and then calculating soil loss by raster-grid modelling with ArclInfo GRID. The rainfall erosivity factor (R) was derived from relationships between rainfall amount and erosivity using erosion plot data from within the catchment. The nature of the relationship was found to be a function of agro-climatic zones of the region. Mean annual erosivities ranged from 145 to 990 J m-2 hr'. For a given amount of rainfall, erosivity was higher in zone IV than in the wetter zones II-III. The soil erodibility factor (K) was estimated using the USLE nomograph and data from laboratory analysis of field samples collected from representative major soil mapping units. The K-values were low to medium, ranging from 0.10 to 0.25 over 84 percent of the basin. The topographic factor (LS) was obtained by creating Digital Elevation Models (DEMs) of the basin with TOPOGRIDTOOL of ArclInfo. These were then used to determine the slope steepness and length factor values, calculated with raster-grid modelling. Although DEMs proved a useful tool, maximum values of both steepness and length had to be set in this reconnaissance study to achieve reasonable results. A finer resolution of input data and a smaller grid cell size are needed for accurate determination. The cover and management factors (C) were obtained by determining the land cover types within the basin using remotely sensed data (SPOT 1 colour composite prints) and ground truthing studies. The factor values were estimated from USLE guide tables and measurements of cover from plots and test sites. Some 70 percent of the basin is covered by rangelands. The conservation practice (P) factor values were estimated from USLE guide tables and then applied to areas where soil conservation had been introduced according to maps obtained from the Ministry of Agriculture. The USLE was validated using data from erosion plots. A value ofR2 = 0.645 was obtained between predicted and measured values but the standard error was rather high (e = 5.745 t ha-1 yr'). Using an annual soil loss of9.0 t ha' yr' as tolerance level, some 36 percent of the basin was found to experience unacceptably high erosion rates. Most of this area was communal grazing land and cropland where soil conservation measures had not been applied. A critical land cover type within the grazing land is shrub land, where vegetation cover is less than 40 percent and high erosion risk was predicted and confirmed by field surveys. EUROSEM could not be integrated within a GIS in the time available for research. It was therefore simulated outside GIS environment, where it was applied to Embori and Mukogodo plot data using separate data sets for calibration and validation. Calibration was used to obtain input parameters for saturated hydraulic conductivity, cohesion and Manning's roughness coefficients. Validation gave correlation coefficients of 0.907 and 0.840 for predictions of storm runoff and soil loss respectively at Embori; the corresponding values for bare soil plots at Mukogodo were 0.895 and 0.577. However, EUROSEM predicted runoff poorly (R2 = 0.570) and failed to predict soil loss at all the vegetated plots at Mukogodo. The model was applied to simulated vegetation covers of barley, maize, grass and forest for a 36.7 mm rainstorm at Embori. The simulated soil losses showed an exponential decrease with increasing cover. At a threshold cover of 70 percent, soil loss diminished to zero under grass and forest and decreased to a minimum value under barley an~ maize. These results support the USLE simulations, which showed that areas with more than 70 percent cover (such as forest) had a low erosion hazard, even with steep slopes

Soil erosion by water in Kenya.

Author: Njoroge, Christopher Robert Kibugi

Awarding University: Cranfield University, England

Level : MSc

Year: 1998

Holding Libraries: Kenya Soil Survey Library ;

Subject Terms: Soil erosion ;

Abstract:

Since 1973, the Kenya Soil Survey (KSS) has adopted and adapted the procedures of the FAO (1976) Framework for their land suitability classification. For effective land use planning, there is a need to evaluate such a system from time to time. The land suitability classification system in Kenya was evaluated through critical literature review and by application to assess the suitability of the Kampi ya Mawe catchment for rainfed maize and rainfed cotton. The land quality ratings currently employed by the KSS at the reconnaissance level were used for the current, qualitative land suitability classification. The soil mapping units of the survey area (19044ha) were compared with land use (maize and cotton) requirements in order to arrive at land suitability classification. The results indicated that 44%, 22% and 34% of the area are moderately suitable, marginally suitable and unsuitable respectively for growing of maize while 7% and 93% of the area are respectively marginally suitable and unsuitable for growing of cotton. The major physical limitations for growing of maize and cotton are rainfall, soil moisture storage capacity, resistance to erosion and availability of nutrients. Consequently, there is need for maintaining high levels of soil conservation and soil fertility standards for the arable land. The non arable land should also be put to the right use and protected from degradation. There is also need for research in order to establish the drought resistant cash crops that can be introduced in this area. Automating land evaluation, revising the land qualities and establishing a land use requirements data bank were identified as among the necessary strategies for further development of land suitability classification in Kenya

A mechanisation strategy model for small-scale farms in the Siaya District of Kenya.

Author: McRota, H J

Awarding University: Cranfield University, England

Level : PhD

Year: 1997

Holding Libraries: Index To Theses ;

Subject Terms: Agriculture ; Siaya District ; Agricultural machinery ;

Abstract:

As yet there is no agricultural mechanisation strategy for any specific area of Kenya so this prompted the present study. Farm surveys were undertaken in 1994 for a period of 12 months to determine conditions in Siaya District necessary for improving crop production and also to establish an inventory of machinery and labour available amongst the small-scale farms. The collected data was statistically analysed and the costing information used for break-down analysis concerning machinery ownership. Linear programming techniques have been utilised to model different farming situations and help make decisions concerning mechanisation. Alternative sources of power were considered, namely hand labour, oxen and tractors. Where tractors were used for primary tillage the crops provided significantly higher grain yields than those where hand and oxen were used mainly due to improved timely cultivations. The costs of cultivation however, revealed that oxen were more than 5 times as expensive than hand and 45 percent more than tractors. For example, the costs of ploughing using oxen costs KSh 3766 whereas; tractors cost KSh 2082 hand labour costs KSh 568 and per hectare. Although extensive use of all the three power sources has been recommended, eventual replacement of ox-cultivation in some areas so that tractor cultivation can be achieved on 50% of all the land within 10 years is recommended. This would only be feasible if second hand 35 kW and 45 kW or equivalent cheaper tractors could be made available to individual farmers, co-operatives and contractors. In addition the government should also improve its tractor hire service and establish rural servicing stations with a view to eventually privatising the service. For the acquisition of machinery, equipment and hand tools, a budget has been worked out for agricultural further mechanisation within Siaya District for five years a head. The loans for the purchase of tractors, machinery and oxen could be repaid within this period. In future the budget and direction of the agricultural mechanisation strategy will be subject to annual review depending on the feed back from the field on the progress of the programme.

An evaluation of the responses of some tea clones to environment in Kenya.

Author: Ng'etich, W K

Awarding University: Cranfield University, England

Level : PhD

Year: 1995

Holding Libraries: Index To Theses ;

Subject Terms: Agriculture ; Tea ; Cloning ; Environment ;

Abstract:

Small differences in environment resulted in large variations in dry matter production and yield between sites and clones. The largest dry matter was from clone TN14/3 (29 t ha-1) but it had low yield (2.1 t ha-1 y-1). By contrast, the largest yield was from clone S15/10 (3.8 t ha-1 y-1), which gave the smallest dry matter (18 t ha-1). These contrasting responses in dry matter and yield were analysed in terms of the interception of solar radiation, radiation use efficiency, partition of dry matter and components of yield. The differences in clonal dry matter production were attributed to site to site variability in solar radiation and temperature which affected the rates of ground cover development and the solar radiation interception. The differences in yield were attributed mainly to differences in air temperature and saturation deficits of the air between the sites which affected the shoot replacement cycles through rates of shoot extension and development. Differences in measured and derived environmental variables between the sites were found. Incident solar radiation differed between the sites by up to 2.4 MJ m-2 d-1. Differences in mean air and soil temperatures between the extreme sites were 2.5oC and 3oC respectfully. A lapse rate of 6.1oC km-1 for mean air temperature was found. Annual rainfall amounts also differed between the sites by up to 700 mm. There were no differences in wind speeds, but there were large differences were in saturation deficits (0.5 kPa) and evapotranspiration (1 mm d-1). During the course of the experiment light interception ranged from less than 5% at planting to more than 80% in April 1994. Radiation use efficiencies for dry matter ranged from 0.30 to 0.45 g MJ-1 in the clones studied and appeared conservative with respect to temperature across the sites. Clone TN14/3 had the lowest base temperature for shoot extension (6.1oC), while clone BB35 had the highest (10.4oC). The base temperatures for shoot extension were 1.3 to 2.9oC higher than those for development, hence the differences in shoot lengths between sites. Shoot replacement cycle ranged from 57 days to 110 days between the sites and was the main determinant of yield.

Feeding habits of camels, Marsabit District, Kenya

Author: Masibho, R W

Awarding University: Cranfield University, England

Level : MSc

Year: 1994

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Camelus dromedarius ; Diet ; Animal behavior ; Marsabit District ;

Abstract:

ABSTRACT NOT AVAILABLE

Investigation into small scale irrigation and water harvesting strategies for the dryland Turkana District, Kenya with reference to the Kalemunyag area

Author: Erukudi, Chris Ekutan

Awarding University: Cranfield University, England

Level :

Year: 1991

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Kalemunyag, Turkana District ; Deserts ; Irrigation ; Water resources ;

Abstract:

ABSTRACT NOT AVAILABLE

Strengthening the management of pastoralism and the livestock development sector in Turkana District, Kenya

Author: Nakhabi, E M W

Awarding University: Cranfield University, England

Level :

Year: 1991

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Pastoralists ; Livestock industry ; Turkana District ;

Abstract:

ABSTRACT NOT AVAILABLE

Steering response analysis of an animal-drawn mouldboard plough [Kenya].

Author: Mutua, J M

Awarding University: Cranfield University, England

Level : PhD

Year: 0

Holding Libraries: Index To Theses ;

Subject Terms: Agriculture ; Agricultural machinery ; Performance evaluation ;

Abstract:

The importance of the animal-drawn mouldboard plough in Kenyan small-scale farming sector is reviewed and the operational problems associated with the implement leading to poor seedbed, poor weed control and operator fatigue. The research aims at firstly providing an insight on the dynamic behaviour of the Victory mouldboard plough when responding to a steering input, and secondly, based on the findings of the dynamic behaviour, advises on design and operational criteria aimed at improving the dynamic performance, hence the quality of work and reduced operator fatigue. There are three parts to this research: part one deals with the theoretical analysis. Here the mathematical equations governing the lateral dynamic behaviour of the animal-drawn mouldboard plough are developed. Part two deals with the experimental verification of the theories developed in part one. Extensive experiments were carried out in the soil bin using a fully instrumented Victory mouldboard plough to test its response to a steering input under different set of parameters viz: two hitch lengths, two hitch points and three different sizes of landsides. Part three advises on the operational criteria aimed at improving the lateral stability and steering responses of the plough under different operating conditions