Agricultural Engineering and Land Planning Collection

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A ‘Smart’ approach on fluoride removal: detection in water sources and removal with biomass
(Sokoine University of Agriculture, 2020-01) Mwakabona, Hezron
Fluoride is one of the common minerals found in natural water, ingestion of which, at moderate concentration, is linked to good dental health. However, ingestion of higher concentrations of this mineral over a period is responsible for fluorosis, a disorder characterised by mottling of teeth and skeletal deformations. Therefore, the WHO sets the highest permissible level of this mineral in drinking water at 1.5 mg/L to limit its effect on public health. Consequently, a water source with fluoride concentration above this highest permissible level is regarded as unfit for human consumption, hence, requiring a treatment before consumption. As such, several studies have explored different low-cost methods to detect and remove this contaminant from drinking water. These include defluoridation and detection of fluoride by plant biomass and iron-based materials, respectively. These materials arc attractive because they have a potential for providing efficacious and cost-effective methods to deal with this water contaminant. In this thesis, the challenges delaying their field application (in detection and removal) of fluoride arc identified and suitable solutions are presented. Furthermore, the properties of iron that make it suitable for fluoride detection and removal enhancement in aqueous media arc presented. A critical review of the studies published over the past three decades on water defluoridation by non-aciivated biomass reveals that, most studies explorc extensively only the defluoridation efficiency/capacily ofthese materials. This bias in studied properties is shown to be due to inadequacy in selection of study parameters, where, the defluoridation mechanisms are poorly studied. This could have resulted in the current poor understanding of their defluoridation mechanisms. Therefore, lessons from these studies were used to identify and propose the “must include” parameters to direct the future studies for better understanding of their defluoridation properties, especially, the defluoridation mechanisms. These are: effect of solution pH, point of zero charge and surface functional groups characterisation before and after material use. For plant biomass ash, the major challenge associated with its application in water defluoridation was found to be related to media-induced contamination of the treated water, notorious being the elevation of the pH of the treated water. This challenge could have repelled many possible applications of this material in water treatment besides its great potentials as water treatment material. In this study, the Cyperus plants were successfully
Accuracy of Giovanni and Marksim software packages for generating daily rainfall data in selected bimodal climatic areas in Tanzania
(Tanzania Journal of Agricultural Sciences, 2014) Kahimba, F. C.; Tumbo, S. D.; Mpeta, E.; Yonah, I. B.; Timiza, W.; Mbungu, W.
Agricultural adaptation to climate change requires accurate, unbiased, and reliable climate data. Availability of observed climatic data is limited because of inadequate weather stations. Rainfall simulation models are important tools for generating rainfall data in areas with limited or no observed data. Various weather generators have been developed that can produce time series of climate data. Verification of the applicability of the generated data is essential in order to determine their accuracy and reliability for use in areas different from those that were used during models development. Marksim and Giovanni weather generators were compared against 10 years of observed data (1998-2007) for their performance in simulating rainfall in four stations within the northern bimodal areas of Tanzania. The observed and generated data were analyzed using climatic dialog of the INSTAT program. Results indicated that during the long rain season (masika) Giovanni predicted well the rainfall amounts, rainy days, and maximum dry spells compared to Marksim model. The Marksim model estimated seasonal lengths much better than the Giovanni model during masika. During short rain season (vuli), Giovanni was much better than Marksim. All the two software packages had better predictions during masika compared to vuli. The Giovanni model estimated probabilities of occurrence of rainfall much better (RMSE = 0.23, MAE = 0.18, and d =0.75) than Marksim (RMSE = 0.28, MAE = 0.23, and d = 0.63). The Marksim model over-predicted the probabilities of occurrence of dry spells greater than seven days (MBE = 0.17) compared to the Giovanni model (MBE = 0.01). In general the Giovanni model was more accurate than the Marksim model in most of the observed weather variables. The web based Giovanni model is better suited to the northern bimodal areas of Tanzania. The Marksim model produced more accurate climatic data when the long-term average climate data are used as input variables. This study recommends the use of rainfall data generated using Giovanni software over Marksim, for areas receiving bimodal rainfall regimes similar to the northern bimodal areas of Tanzania.
Assessing the effectiveness of locally made clay pot as an irrigation device.
(Sokoine University of Agriculture, 2011) Solo, Mahatsindry Randzato
Among traditional irrigation systems, pitcher irrigation is one of the most efficient. Water seeps out of a buried pitcher due to the pressure head gradient across the wall of the pitcher directly into the root zone of the irrigated crop. The pressure gradient results from a positive pressure head inside the pitcher and negative pressure head at the outer surface of the pitcher which is in contact with soil. Pitcher irrigation is a cost effective traditional technique, which is easy for small scale farmers to comprehend with. This study considered the effectiveness of locally made pitchers as a micro-irrigation device using beans and amaranths crops. The experimental design was 2x3 factorial arrangements of treatments in a split plot design. The main-plots were two different initial soil moisture contents i.e. soil moisture content at field capacity (31 %, vol.) and 26 % (vol.). The sub-plots were three different plant densities i.e. 4 plants/pot, 6 plants/pot and 8 plants/pot and were replicated three times giving a total of 18 combination treatments. A positive relationship was found between seepage rate and actual evapotranspiration for all pitchers (R = 0.37) showing a sign of auto-regulative capabilities. Under beans, the pitchers were not effective in water saving in all the combination treatments because of high water loss through deep percolation because of poor pot characterization. However under amaranths the pitchers were effective in optimizing the water applied. The water applied was not statistically different (P < 0.05) for all the treatments. These results show that clay pots had low application efficiency. However the pots can still be used on amaranths, with a plant density of 16 plants/pot and at initial soil moisture content of 26 % (volume).
Assessment of the land use changes due to traditional irrigation activities: the case study of four villages around Ruaha Mbuyuni, Iringa and Morogoro Tanzania
(Sokoine University of Agriculture, 2002) Rugenga Elizabeth
The study on assessment of land use changes due to traditional irrigation activities was conducted in four villages around Ruaha Mbuyuni from June 2000 to June 2001. Three sets of aerial photographs (1955, 1976 and 1999) were used, interpreted on mirror stereoscope and analysed using GIS-ARC/INFO program. The area of each class was' calculated for each data set from which the rate of expansion of irrigated farms was determined. The questionnaire survey was conducted to collect information on the historical changes in natural resources and socio-economic activities responsible for land use changes and analysed using SPSS program. Stratified random sampling was also conducted for soil physical and chemical analyses. By using rating procedures the contribution of soil properties in land use changes was carried out. The results showed that irrigated fields expanded by 2056.8ha and 1528.6ha with expansion rate of 97.94ha/yr and 66.46ha/yr from 1955 to 1976 and 1976 to 1999 respectively. Human population increased from 2886 to 16877people between 1967 and 1998. Irrigation activities have been observed to increase the extent of socio-economic activities like firewood gathering and building. The results for soil analysis indicated that, total nitrogen, available phosphorus and organic matter content was low in all fields and therefore low soil fertility in the area. Exchangeable Na were observed to be high in some fields and having high potential to cause soil salinity and sodicity. Other chemical properties i.e pH values, Ca, Mg and CEC were observed to be within the acceptable range for irrigation activities and crop productivity. The soil physical properties indicated that the bulk density of the soil were within the acceptable range for water infiltration and plant roots penetration. The soil textural class was observed to range from sand loam to sand clay loam for the topsoil and sand to clay for the subsoil. Generally, the results have shown that the pattern of land use changes in the study area were due to irrigation activities taking place in the area which has influenced population growth and socio-economic development.
Assessment of the utilization, management and operating costs of agricultural tractors in the Chemelil Sugar Belt in Kenya.
(Sokoine University of Agriculture, 1992) Onyango, Ogweno Samuel Roger
The research undertook to study the utilization, management and operating costs of agricultural tractors used in the Chemelil sugar belt in Western Kenya. Historical cost data spread over a span of 16 years were obtained for 141 tractors operated by three different owners in the belt. The data was used to assess the level of utilization and operating costs and to test mathematical models for predicting tractor resale values, repair and maintenance costs, annual operating costs as well as establishing the factors that influence them. It was found that tillage tractors in the belt had an average annual use of 1040 hours and transport tractors 1230 hours and that both category of tractors had restricted utilization due to limits imposed by maximum hectarage for tillage tractors and queuing discipline at the sugar factory and in the fields for cane transport tractors.Mathematical models were formulated and tested for relation between ratio of tractor resale value to its current purchase and repair initial and depreciation age,maintenance costs purchase price and relation expressed tractor between cumulative as a percentage, of cumulative depreciation against tractor age and resale value to its annual operating cost against tractor age. Multiple regression computer software in the MSTATC version facility package was used to test the 1 .41 models. Important empirical relations were derived from the results of the tests. Qualitative factors were the investigated quantities shown to influence quantitatively and that the control of the qualitative factors could reduce operating costs.A relation for predicting annual operating costs of a tractor basing on its replacement value was found. The relation could also be used to predict the tractor’s optimal replacement point similar given the future substitutive models. found to defy prices of or The trend of actual depreciation was basic the depreciation models. Purchase assumptions of accounting It was demonstrated that due to high inflation rates it is not possible to assign terminal salvage values to tractors notwi thstandi ng.in good running order, their age not with standi ng.
Contribution of land use to rodent flea load distribution in the plague endemic area of Lushoto District, Tanzania
(Tanzania Journal of Health Research, 2014-07) Hieronimo, Proches; Kihupi, Nganga I.; Kimaro, D. N.; Gulinck, Hubert; Mulungu, Loth S.; Msanya, B. M.; Leirs, Herwing; Deckers, J
Fleas associated with different rodent species are considered as the major vectors of bubonic plague, which is still rampant in different parts of the world. The objective of this study was to investigate the contribution of land use to rodent flea load distribution at fine scale in the plague endemic area of north-eastern Tanzania. Data was collected in three case areas namely, Shume, Lukozi and Mwangoi, differing in plague incidence levels. Data collection was carried out during both wet and dry seasons of 2012. Analysis of Variance and Boosted Regression Tree (BRT) statistical methods were used to clarify the relationships between fleas and specific land use characteristics. There was a significant variation (P ≤ 0.05) of flea indices in different land use types. Fallow and natural forest had higher flea indices whereas plantation forest mono-crop and mixed annual crops had the lowest flea indices among the aggregated land use types. The influence of individual land use types on flea indices was variable with fallow having a positive effect and land tillage showing a negative effect. The results also demonstrated a seasonal effect, part of which can be attributed to different land use practices such as application of pesticides, or the presence of grass strips around fields. These findings suggest that land use factors have a major influence on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point to the need for a comprehensive package that includes land tillage and crop type considerations on one hand and the associated human activities on the other, in planning and implementation of plague control interventions.
Economic valuation of irrigation water in smallholder farming system in rwanda: the case of Kibaya – Cyunuzi scheme
(Sokoine University of Agriculture, 2012) Urujeni Sandrine
Rwanda is in a current shift of management of state controlled irrigation schemes to farmers through the Irrigation Management Transfer (1MT) programme. However, such water management decisions require conceptually correct and empirically accurate estimates of the economic value of water. This study was carried out to determine the economic value of irrigation water in a smallholder irrigation scheme of Kibaya - Cyunuzi. Data was collected from 110 respondents within the scheme. The data was analyzed using descriptive and quantitative methods. The Residual Computation Method was used to compute the economic value of irrigation water for paddy rice - the main crop cultivated in the scheme. The Contingent Valuation Method was employed to elicit the farmers’ willingness to pay for irrigation water and its related infrastructure. Socio-technical analysis helped to capture the process of water control and management through Water Users Associations. Results showed that the average economic value of water in irrigated paddy was low (5.33 Rwf/m3), mainly due to poor management of water. Water productivity was also low (0.08 kg/m3) due to an insufficient supply of water to the scheme. The CVM analysis showed that on average, the respondents were willing to pay 8000 Rwf per ha per annum for irrigation water. IMT impact assessment showed that WUAs are the realms of interaction for different stakeholders involved in water management. The problems farmers were facing in improving water productivity in the scheme were identified but the solutions require joint effort among the stakeholders. Policy decisions related to water sector investments, allocation and management could be better guided if the key dimensions of water i.e. water availability and use, are properly taken into account in valuation.
Effect of grating, chipping, dry fermentation and sun drying on cyanide level of cassava in Tongwe village.
(Sokoine University of Agriculture, 2009) Khatib ,M. A.
This study was conducted to evaluate effectiveness in cyanide reduction by four different methods of processing cassava roots, two traditional (dry fermentation and direct sun drying) and two improved methods (grating and chipping) and also assess losses due to cassava processing in Tongwe village (Muheza District). Presence of mycotoxin-producing organisms in fermented cassava flour was examined. Cyanogens were determined using the AOAC alkaline titration method. The microbial growth was done on plate using Sabouraud’s Dextrose Agar (SDA). The cyanide level, in the processed cassava differed significantly (p<0.05). Improved methods were more effective than traditional. The mean cyanide was; 6.79, 7.96, 8.96 and 9.90 mg HCN/kg DWB for grating, chipping, dry fermentation and direct sun drying, respectively. Identification of mould revealed the absence of mycotoxin producing organisms and therefore ruled out the possibility of presence of mycotoxins in the dry fermented cassava flours collected from 60 households in Tongwe and 10 samples prepared in Tongwe cassava processing unit. Losses due to processing in all four methods were determined by calculating the difference between peeled fresh cassava weight and the weight of flour produced after processing. Results showed significant differences (p<0.05) between the traditional and improved methods studied. The mean percentage losses were; 67.28, 69.73, 51.83 and 54.14 for grating, chipping, dry fermentation and direct sun drying, respectively. Sensory evaluation done at SUA and Tongwe showed significant differences (p<0.05) in preferences between the stiff porridge prepared using flour from all four methods of processing cassava, the most preferred product being ugali from chipped cassava flour. This experiment has indicated that improved methods are more effective in cyanide reduction than traditional ones. However, traditional methods were more economical in processing losses and that there were no mycotoxin-producing organisms in fermented cassava flour. Both methods produce acceptable products worth encouraging if losses are minimized.
Effects of farmer-initiated modifications of water control structures on performance of irrigation system:a case study of Mkindo Scheme, Morogoro, Tanzania
(Sokoine University of Agriculture, 2000) Matiku,John Magorombe
A study to assess the effects of farmer-initiated modifications of water control structures on the performance of the irrigation system in Tanzania was carried out at Mkindo farmer managed irrigation scheme (FMIS) in Morogoro region. The scheme had two phases. The changes made on the original water control structures were assessed, the performance of the existing water distribution system, and the effect of the existing water control structures on performance of the irrigation system was evaluated. The result of the study shows that changes were made by farmers on the original design of already constructed water control structures in the scheme as follows: some of the field canals and the original centrally located field drains were removed by farmers in order to increase irrigable area (bigger utilised land area). Therefore, some farmers were doing field-to-field irrigation method; the main drainage for phase-I has been converted to field irrigation canal by nearby farmers; dimension of existing paddy field earth bunds and secondary canal banks were smaller than original ones; water harvesting from main and secondary canal by farmers outside the scheme exists and no water control gates (wooden stop-logs originally provided) exists at division box openings and at turnout level for the scheme. Applicable indicators for the performance of FMIS are quantified as follows:-Overall irrigation efficiencies were 6% and 8.3% for phase-I and phase-II of the scheme respectively: Average productivity dropped from 6.6 ton/ha in 1995/96 to 3.1 ton/ha in1998/99 season. The organisation of Mkindo FMIS was appropriate, however, the scheme was weak in irrigation management as the essential operation and maintenance activities were not carried out effectively. The scheme had canal maintenance problem. There was a corresponding big error in waler adequacy of 72% and 68% for both phase- I and phase-II of the scheme respectively arising from improper water control along the main canal and at secondary canal offtake. Both phase-I and phase-II of the scheme were not able to distribute water equitably, reliably as well as maintaining a correct field water depth from tilling to flowering and grain formation stage. This was shown by relatively high error of equity of 18% and 20% for both phases respectively. These figures are far greater than zero, which is the indicator for highest performance. Therefore, the FMIS in Tanzania may perform better, or be sustainable, if original design of already constructed water control structures are maintained (i.e. not changed) by farmers at operation stage. This emphasises farmer’s involvement and empowerment at planning, design and construction stages of the scheme.
Effects of Mswiswi watershed degradation on stream flow in Usangu village irrigation project
(Sokoine University of Agriculture, 1997) Malongo,Gerald Wanda Sere
The effect of Mswiswi watershed degradation on stream flow was investigated as one of 5 watersheds used by Usangu Irrigation Project as source of water. The watershed was calibrated upon itself by establishing four watershed degradation scenarios as the basis for comparison of watershed degradation parameters and stream flow characteristics. The established degradation scenario were 1960-65, 1965-75, 1975- 86 and 1986-92. The 1960-65 degradation scenario was taken as the control period i.e the period for which watershed degradation was at the minimum level. Therefore all parameters of watershed degradation and stream flow of certain probabilities in 1960-65 were compared with the same parameters in other three scenarios.Watershed degradation evidence analyzed from aerial photographs of 1977 and 1992 shows that: watershed forest loss was 0.105 , 0.032 and 0.497 km2/year for mixed forest,forest reserve and low dense miombo woodland, respectively. Soil degradation through gully expansion was 0.049 km2/year.The study shows that precipitation in Mswiswi watershed is decreasing from 1963-1986. This has been evidenced by decreasing trend of 5-year moving averages of precipitation and precipitation of certain probabilities. Comparison of watershed degradation parameters in four degradation scenarios shows that there were a differences among scenarios as a result of degradation. There was a general decreasing trend of parameters such as watershed storage and watershed loss factor from degradation scenario of lower order (1960-65) to scenario of higher order (1986-92). This means that the trend of decrease in watershed degradation parameters was from 1963-1989. Watershed degradation parameters such as curve number and watershed degradation factor were, on the contrary, increasing from 1963-1989. The decrease of watershed loss and watershed storage indicate that watershed was degrading as has been evidenced by watershed forest loss. Similar indication of watershed degradation was shown by increase of curve number and watershed degradation factor. This study shows that there was a relationship between increasing trend of runoff and increasing or decreasing trend of watershed degradation parameter from one degradation scenario to another for a particular probability of exceedance. Runoff of 10 % probability was increasing from watershed degradation scenario of lower order to scenario of higher order as watershed storage and loss factor of the same probability was decreasing. The trend of changes in base flow of particular probability of exceedance was more related to the trend in which watershed degradation factor of the same probability was varying. Stream flow from Mswiswi watershed is affected by both climatic changes and watershed degradation. To evaluate the effect of watershed degradation alone, the developed runoff and base flow models were run for equal rainfall events, so as to see how the watershed in the process of degradation in different periods was responding or would respond to the same rainfall events. The results of model utilization show that runoff was increasing as the watershed was degrading for equal rainfall events. In the case of base flow, the results of model utilization show that watershed degradation was causing cyclic trends of base flow variability. The maximum and minimum base flow for equal rainfall were having recurrence intervals of ten years. The magnitude of maximum and minimum base flow was decreasing with time as watershed was degrading for equal rainfall events.
Enhancing response farming for strategic and tactical management of risks of seasonal rainfall variability
(2014) Admassu, H.; Mahoo, H. F.; Rwehumbiza, F. B. R.; Tumbo, S. D.; Mogaka, H.
Seasonal rainfall variability, particularly the uncertainty with respect to the direction and extent that variability will assume in a given season, forms the greatest source of risk to crop production in semi-arid areas of Ethiopia. Equipping vulnerable communities, in advance, with the expected date of onset of a cropping season, is crucial for smallholder farmers to better prepare to respond and manage the uncertainties. Therefore, rainfall prediction, particularly development of models that can foretell the date of onset of next cropping season is crucial in facilitating strategic agronomic planning and tactical management of in-season risks. A twenty-four-year climatic data study was conducted for Melkassa Agricultural Research Centre (MARC) in semi arid Ethiopia, to develop onset date prediction models that can improve strategic and tactical response farming (RF). A sequential simulation model for a build up of 15 to 25 mm soil water by April 1st, was conducted. Simulation results revealed a build up of soil water up to 25 mm, to be the most risk-wise acceptable time of season onset for planting of a 150-day maize crop. In the context of response farming, this was desirable as it offers the opportunity for farmers to consider flexible combination production of maize (Zea mays L.) varieties of 120 and 90 days in the event of failure of earliest sown 150-day maize crop. Thus, to allow for flexible combination production of the three maize varieties, predictive capacity was found crucial for April onset of the next crop season. Accordingly, based on the consideration of pre-onset rainfall parameters, the first effective rainfall date varied considerably with the date of onset of rainfall. Regression analyses revealed the first effective rainfall date to be the best predictor of the date of onset (R2 = 62.5%), and a good indicator of the duration of next season (R2 = 42.4%). The identified strategic predictor, the first effective rainfall date, enabled prediction of time of season onset and season length by a lead time of two to three months. This markedly improved Stewart’s RF. The date of onset of the next crop season was also found to be a useful predictor of season duration (R2 = 87.3%). Strategic agronomic planning should be adjusted according to the first effective rain date, and tactically according to what date of rainfall onset informs us about expectations in the duration and total season water supply.
Establishment of digital land resources database for land use planning: a case study of eastern Morogoro rural district, Tanzania
(Sokoine University of Agriculture, 2001) Munisi, Abbas Idriss Mawenya
A study was conducted in the eastern part of Morogoro Rural District to establish digital land resources database which could be used when making decision on land use planning. Four Divisions namely; Mkuyuni, Matombo, Mvuha and Bwakira Chini were included in the study. Land resources data for climate (rainfall and temperature), physiography and soils and socio-economic were collected and compiled from field survey and other sources. The data were analysed, characterised and computerized to generate digital land resources database. The generated databases were stored, manipulated and geoproccssed using computer and various softwares to produce digital spatial and non-spatial information which included thematic maps for elevation, climate, length of growing period (LGP), soils and agroecological zones. Tables on land attribute database, descriptive soil legend and reports were other digital products generated. The digital databases were then used to run land evaluation for the area. Automated land evaluation system (ALES) was employed to compute physical land suitability Evaluation for specified land utilization types (LUTs) i.e. maize, rice, citrus and sesame. The results of the suitability evaluation showed that 57% of the area could be used to produce maize, 85% to produce citrus, 22% paddy and 78% to produce sesame; with production potentials ranging from moderate to poor for all studied LUTs. The major limitations were erosion hazard, nutrient availability, rooting condition and wetness. Citrus was more suited to the area, followed by sesame, maize and lowland rice. The study has demonstrated that greater capability for storing, displaying spatial and non-spatial data in different forms and scales, data analysis and computation of land evaluations exist when land resources data are captured in digital format. Basing on this conclusion, it is highly recommended that land resources data at any level should be inventoried and automated to simplify the process of land use planning.
Evaluation of centre pivot sprinkler irrigation system performance and its effect on sugar cane yield at Kagera Sugar Estate.
(Sokoine University of Agriculture, 2010) Reuben,Paul
Centre pivot irrigation is a medium to low pressure sprinkler system capable of irrigating large circular areas. It consists of a galvanised steel lateral supported by “A" - shaped frame mounted on powered wheels. It rotates about a fixed point at the centre of the irrigated field. The study evaluated the performance of a centre pivot spray nozzle irrigation system and its effects on sugarcane yield at Kagera Sugar Estate, Tanzania. The specific objectives were to assess: (i) the performance of the centre pivot spray nozzle sprinkler system (ii) soil parameters that influence cane yields and (iii) irrigation water quality. High and low yielding areas were represented by centre pivot GP7 and BP5. The results showed that low yields were contributed by poor performance of centre pivots and soil parameters. Centre pivot GP7 had average coefficient of uniformity (CU) of 96.91% while it was 86.28% for BP5; average distribution uniformity (DU) of 95.1% and 78.23%; average potential application efficiency (PELQ) of 86.83% and 79.14%; average application efficiency (AELQ) of 64.97% and 59.36%, respectively. The minimum recommended values for CU, DU, PELQ, and AELQ were 85%, 75%, 90%, and 85%.The performance parameters for GP7 were within the recommended values except AELQ and PELQ which was lower than the recommended value. The PELQ and ALQ for BP5 were lower than the recommended value. In general, the performance parameter estimated for GP7 were higher than for BP5 as the result of differences in sugarcane yield. For instance, fields under GP7 and BP5 had average yields of 123 and 74 tonnes per hectare respectively. Soil parameters that contributed to low yield were low water holding capacity., low cation exchange capacity; high acidity; poor structure and compaction by farm machinery. Irrigation water quality was high that could not contribute to low yield.
Evaluation of Irrigation Water Quality for Paddy Production at Bumbwisudi Rice Irrigation Scheme, Zanzibar
(TAJAS, 2016) Kahimba, F.C; Ali, R. M; Mahoo, H.F
Evaluation of sprinkler irrigation performance at Simunye Sugar Estate in Swaziland.
(Sokoine University of Agriculture, 1995) Magongo,Bongani Harmon
The performance the evaluated study irrigation system at Simunye,objectiveswere:parameters,(1)To identify the original parameters,(2)To investigate performance parameters,whether the system is operating as designed,and (3)To recommend suitable changes in the operation and system configurations that could be implemented to improve the irrigation efficiency. The results showed that there were no available design parameters on which the system of Simunye Sugar Estate was designed. The system showed a uniformity coefficient (Cu)of 76%,which is within recommended Cu range for design market acceptance.The Distribution uniformity obtained was 61% and the potential application efficiency for the low-quarter (PELQ) was found to be 54%.Both of these parameters were lower than the recommended ones, and they were significantly different when compared with the recommended ones of at least 67% and 75-85%, respectively.The actual application efficiency for the lower-quarter (AELQ) was found to be 45% which is too low when compared to the PELQ.The minimum basic infiltration rate of the soils irrigated by sprinkler system was 5 mm/h. Factors which contributed to the non-uniformity of the system were wind velocity and wind the direction operating pressure (which was too high or lower than the recommended one for the system), evaporation losses,and the sprinkler spacing. From the results it was shown that management of the irrigation system had an effect on the poor performance of the system.
Farmers’ utility of irrigation water supply as a method of assessing irrigation system’s performance.
(Sokoine University of Agriculture, 1997) Makongoro, Elfariji Kohi
A model which employ Farmers’ Utility of Irrigation Water Supply (FUIWS) in assessing irrigation system’s performance has been developed in this study. The methodology was tested through a Case Study at Lower Moshi Farmer Managed Irrigation Scheme (Lower Moshi FMIS). The main objective was to investigate FUIWS as a method of assessing the performance of irrigation systems. Strong relationship was observed between Relative Water Supply (RWS) and FUIWS. Wherever RWS was high FUIWS was also high and vice versa as proved by positively large covariance value obtained. However, this relationship was identified as non linear correlation by significance correlation coefficient test. The graphs plotted showed relationship of the type: R = aen Where:R = RRWS in paddy fields. U' = UFUIWS. a and n are constants. In this particular Study, the scheme model obtained was: R = 0.377e,1,2SU Similar block models were established. The homogeneity test on the block mean values showed that; RWS have the same degree of variability for all levels of FUIWS. This indicated the ability of the scheme model to be used in place of block models. Different "a" and "n" constant values obtained between blocks indicated different irrigation management levels between blocks. The method was tested in paddy rice only, therefore more work is needed to test it in upland crops; traditional and improved Farmer Managed Irrigation Scheme (FMIS). Also, more research is required to establish whether threshold values "a" and "n" are universal or not and what factors influencing them.
Human activity spaces and plague risks in three contrasting landscapes in Lushoto District, Tanzania
(Tanzania Journal of Health Research, 2014-07) Hieronimo, Proches; Gulinck, Hubert; Kimaro, D. N.; Mulungu, Loth S.; Kihupi, Nganga I.; Msanya, B. M.; Leirs, Herwing; Deckers, J.
Since 1980 plague has been a human threat in the Western Usambara Mountains in Tanzania. However, the spatial-temporal pattern of plague occurrence remains poorly understood. The main objective of this study was to gain understanding of human activity patterns in relation to spatial distribution of fleas in Lushoto District. Data were collected in three landscapes differing in plague incidence. Field survey coupled with Geographic Information System (GIS) and physical sample collections were used to collect data in wet (April to June 2012) and dry (August to October 2012) seasons. Data analysis was done using GIS, one-way ANOVA and nonparametric statistical tools. The degree of spatial co- occurrence of potential disease vectors (fleas) and humans in Lushoto focus differs significantly (p ≤ 0.05) among the selected landscapes, and in both seasons. This trend gives a coarse indication of the possible association of the plague outbreaks and the human frequencies of contacting environments with fleas. The study suggests that plague surveillance and control programmes at landscape scale should consider the existence of plague vector contagion risk gradient from high to low incidence landscapes due to human presence and intensity of activities.
Human activity spaces and plague risks in three contrasting landscapes in Lushoto District, Tanzania
(Tanzania Journal of Health Research, 2014-07-14) Hieronimo, P.; Gulinck, H; Kimaro, D.N; Mulungu, L.S; Kihupi, N.I; Msanya, B.M; Leirs, H; Deckers, J.A
Since 1980 plague has been a human threat in the Western Usambara Mountains in Tanzania. However, the spatial-temporal pattern of plague occurrence remains poorly understood. The main objective of this study was to gain understanding of human activity patterns in relation to spatial distribution of fleas in Lushoto District. Data were collected in three landscapes differing in plague incidence. Field survey coupled with Geographic Information System (GIS) and physical sample collections were used to collect data in wet (April to June 2012) and dry (August to October 2012) seasons. Data analysis was done using GIS, one-way ANOVA and nonparametric statistical tools. The degree of spatial cooccurrence of potential disease vectors (fleas) and humans in Lushoto focus differs significantly (p ≤ 0.05) among the selected landscapes, and in both seasons. This trend gives a coarse indication of the possible association of the plague outbreaks and the human frequencies of contacting environments with fleas. The study suggests that plague surveillance and control programmes at landscape scale should consider the existence of plague vector contagion risk gradient from high to low incidence landscapes due to human presence and intensity of activities.
Impacts of climate change on agriculture: What, when, where and how?
(2015) Tumbo, Siza; Sanga, C
One of the key messages emerging out of the recent IPCC reports is that the climate change is real, happening and will continue to happen for the foreseeable future. The report also estimates with high confidence that the negative impacts on agriculture outweigh the positives which makes adaptation an urgent and pressing challenge. However, adaptation planning requires accurate information about where, when and how the impacts are going to be felt and who will be more vulnerable. Eastern Africa is considered as one of the most vulnerable regions in the world due to its high dependence on agriculture for subsistence, employment and income. Generally the region experiences prolonged and highly destructive droughts covering large areas at least once every decade and more localized events more frequently. The negative impacts of climate are not limited to the years with extreme climatic conditions. Even with normal rainfall, the countries in the region do not produce enough food to meet their needs. Overlaid on this challenging scenario is the dominance of semi-arid to arid climatic conditions which are marginal for crop production, degraded soils, extreme poverty and lack of infrastructure which make the countries in the region highly vulnerable to current and future changes in climate. There is a rapidly growing literature on vulnerability and adaptation to increased climatic variability and change but most of these assessments are based on statistical and empirical models that fail to account the full range of complex interactions and their effects on agricultural systems. For developing and implementing adaptation programs, more detailed information about how the components of the prevailing farming system such as which crops and varieties are more vulnerable and which management practices are unviable under the predicted climates is needed. However, several problems such as non-availability of downscaled local level climate change projections, lack of information on how the projected changes impact agricultural systems and scarcity of information on how these changes on production and productivity of agriculture translate into economic impacts including food security at household and national levels are constraining such an assessment.
Influence of institutional set up on performance of traditional irrigation schemes. a case study of Nyandira wards, Mvomero district, Tanzania.
(Sokoine University of Agriculture, 2016) Sumuni,Philip Mathew
This study was conducted in Nyandira ward, Mvomero District, Tanzania to evaluate the influence of institutional set up on performance of traditional irrigation schemes. The study was envisaged to produce knowledge of institutional framework to guide performance of traditional irrigation schemes on efficient use of water resources. GPS reading to digitise the traditional canal, farmer’s interview, focus group discussion and V- notch weir for canal flow measurements were used for data collection. Out of twelve traditional canals, four canals namely Fuku, Mbakana Kati, Mzinga and Nyamiseta No. I were purposively selected. The data were analysed using descriptive statistics, inferential statistical analysis and content analysis. Results showed that out of 93 interviewed farmers (91.4%) 85 people out of 93 were not aware of the National Water Policy of 2002 whereas only (8.6%) 8 people out 93 were aware of the National Water Policy of 2002. This shows that policies are formed and remain to the management (Decision and Policy makers) while people on the ground who are the actual implemented are not aware of what is going on. The results also showed that the majority of the respondents (93.5%) 87 people out of 93 in the study area were not aware of the Water Resources Management Act of 2009. This implies that the community members do not understand their role in water conservation and management in line with the Water Resources Management Act of 2009. The conveyance efficiency for the four canals, i.e. Fuku, Mbakana Kati, Mzinga and Nyamiseta No. 1 were calculated and found to be 63.05%, 62.74%, 60.89% and 60.5% respectively which is fairly good. But the overall efficiency of 34%, 32%, 33% and 37% for Fuku, Mbakana Kati, Mzinga and Nyamiseta respectively was low due to the fact that canals are unlined.

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