IRRIGATION WATER-USE IN MOGOTIO IRRIGATION
SCHEME, MOGOTIO CONSTITUENCY, KENYA
BY
VAISHAL JEPKEMOI KORIR
A RESEARCH PROJECT SUBMITTED TO THE KENYA NATIONAL EXAMINATION COUNCIL IN PARTIAL FULFILMENT FOR THE REQUIREMENT OF THE AWARD OF DIPLOMA IN GENERAL AGRICULTURE
JULY 2022
DECLARATION
This research project is my original work and has not been presented for a certificate in any Technical Training college.
NAME: Vaishal Jepkemoi Korir
Signature………………………………………Date ……………………………
Supervisor: Mr. Kandie
Department of Agriculture
Signature………………………………………Date ……………………………
DEDICATION
I dedicate this research project to my parents for their support during my entire period of study. May they live long to reap the benefits that will accrue from the study.
ACKNOWLEDGEMENTS
This study benefited from valuable inputs by several students and supervisor, to whom I remain greatly indebted. Due to limited space, only a few are mentioned here.
ACRONYMS AND ABBREVIATIONS
| ASIP | Agricultural Sector Investment Program | |||
| CRS | Constant Returns to Scale | |||
| DMU | Decision Making Unit | |||
| FAO | Food and Agriculture Organization of the United Nations | |||
| GDP | Gross Domestic Product | |||
| GPS | Global Positioning System | |||
| IMF | International Monetary Fund | |||
| IWMI | International Water Management Institute | |||
| IWUA | Irrigation Water Users Association | |||
| NEMA | National Environmental Management Authority | |||
| NEPAD | New Partnership for Africa’s Development | |||
| NIB | National Irrigation Board | |||
| SAEFL | Swiss Agency for the Environment, Forests and Landscape | |||
| SPSS | Statistical Package for Social Sciences | |||
| UN | United Nations | |||
| VRS | Variable Returns to Scale | |||
| WMU | Water Management Unit | |||
| WRMA | Water Resources Management Authority | |||
ABSTRACT
Given the increasing freshwater scarcity, the performance of irrigation is critical in increasing and sustaining agricultural productivity in the water-scarce and largely arid and semi-arid Kenya. Irrigation currently accounts for most of the water withdrawals in the country, and the required improvement in the performance of irrigation is hampered by inadequate benchmarks upon which to base effective planning. This study was conducted between April and May 2022 to analyze the economic efficiency of irrigation water-use in Mogotio Irrigation Scheme in Mogotio District, Kenya. The objectives of the study were to determine response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme, the economic water-use efficiency, and the main factors explaining the efficiency. This required data on quantities of water withdrawn for irrigation, irrigated land area, working capital, labour and rice output, as well as other technical and socio-economic features of the irrigators. Questionnaires and field observations were used to collect secondary data on these variables from a sample of 121 out of the 4,189 rice farms. The results were presented in form of tables, and graphs, from which discussions, conclusions, and recommendations were made. The study revealed that the quantity of irrigation water as was used had positive but insignificant effect on rice output, probably implying over-use of water. Technical, allocative, and overall economic ( cost ) water-use efficiencies in the Scheme were 69%, 91%, and 63% respectively. Further, technical efficiency was explained mainly by the actual duration of land preparation, water conflicts, drain water re-use, and availability of water in the canal. It is recommended that technical and institutional changes be made in order to improve technical efficiency of water use in the Scheme. Specifically, these include dry land preparation, shortening of land preparation period, cultivation of more water-efficient rice varieties, non-flood weed control, and construction of large-scale water storage infrastructure. Other recommendations are canal lining, installation of water control structures, drain water re-use, capacity-building of IWUAs, and integrated approaches to water management mogotio irrigation basins. This study contributes to effective and efficient decision-making on irrigation planning and management in Mogotio Scheme. It will also facilitate the development and implementation of the National Irrigation Policy that is currently being formulated. In addition, it is expected to generate more interest in irrigation research in Kenya to help achieve the national macroeconomic development objectives of poverty alleviation, food security, employment creation, and industrialization.
TABLE OF CONTENTS
ACRONYMS AND ABBREVIATIONS. iv
1.1 Background to the Study. 1
1.2 Statement of the Problem.. 1
1.6 Justification and Significance of the Study. 3
1.6.1 Justification of the Study. 3
1.6.2 Significance of the Study. 3
1.7 Scope and Limitation of the Study. 4
1.7.2 Limitations of the Study. 4
2.2 Importance of Rice Farming in Kenya’s Economy. 7
2.2.1 Agricultural Productivity and Kenya’s Economic Development 7
2.2.2 Kenya’s Agricultural Productivity and Expansion of Rice Cultivation. 8
2.2.3 Irrigation Water-Use and Rice Cultivation. 9
2.3 Role of Water-Use Efficiency on Sustainable Irrigation. 9
2.3.1 Water Scarcity Trends and Sustainable Irrigation. 9
2.4 Types and Measures of Efficiency. 10
2.4.2 Efficiency Measurement Concepts. 11
2.5 Theoretical Background to Water-Use Efficiency. 12
2.6 Definition of Water-Use Efficiency Terms. 12
2.7 Empirical Studies on Resource-Use Efficiency. 12
2.8 Gaps Identified in the Literature. 14
2.9 Technical and Socio-economic Factors of Water-Use Efficiency. 14
2.9.1 Quantity of Irrigation. 14
2.9.8 Farmer’s Level of Education. 16
2.9.10 Farmer’s Irrigation Experience. 17
2.9.11 Farm Position along the Canal 17
2.9.12 Duration of Land Preparation. 18
2.9.13 Irrigation Water Conflicts. 18
DATA AND RESEARCH METHODOLOGY.. 19
3.4 Definition of the Variables. 20
3.4.2 Independent Variables. 20
4.3 Economic Efficiency of Irrigated Rice Production. 24
4.3.1 Irrigation Water Use. 24
4.4 Factors that Determine Economic Efficiency of Irrigated Rice Production. 26
4.4.1 Summary of Socio-Economic Characteristics. 26
CONCLUSIONS AND RECOMMENDATIONS. 28
5.3 Suggestions for Further Studies. 29
CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
The world faces challenges of relentless environmental degradation, growing population pressure, expanding need for food and fibre, and increasing scarcity of freshwater resources. Water resources are getting increasingly scarce due to the impacts of the emerging trends in climate, population, technology, and socioeconomics, with one-third of the global population facing water scarcity (Clarke & King, 2004; Rockstrom, 2003; Sheikh, 1995).
The dwindling water resource availability is a serious challenge to the sustainability of agricultural-based economies in Sub-Saharan Africa like Kenya where there is great need for increasing the agricultural yields, environmental protection, and poverty alleviation. With the rainfall getting increasingly erratic and unreliable in the region, per capita food output has experienced a decline in recent years with consequent intensification of hunger (FAO, 2008; Sen, 1998;
These challenges call for a concerted effort to conserve water by enhancing its efficient utilization, improving the productivity of crops with respect to land and water resources, as well as investing in appropriate irrigation technology. This study analyzes economic efficiency of irrigation water-use in Mogotio Scheme, which is Kenya’s largest public-funded irrigation project. The established efficiency will form a benchmark to facilitate effective planning for improved irrigation water management for the expansion and sustainability of the project.
1.2 Statement of the Problem
Kenya is water-scarce with diminishing availability of usable water, and the country plans to expand irrigation that already dominates national water use (Clarke & King, 2004; Republic of Kenya, 2007a, 1992). Yet, irrigation expansion is likely to intensify water scarcity if the equally expanding non-agricultural sectors are to get their equitable share of the limited resource. This is expected to intensify conflicts within as well as among the socio-economic sectors. Already the sustained irrigation expansion in Mogotio Scheme and the great fluctuation in the discharges of Nyamindi and Thiba Rivers, whose water is used for irrigation, have rendered Scheme water management difficult (Kamundia, 2008). So far, the Scheme lacks appropriate quantitative and quantitative indicators to gauge water-use efficiency despite its national importance as a model for public irrigation projects. Since efficiency is an important factor of sustainability, the improved productivity of the current and future irrigation activities lies in the efficient utilization of the available water. This requires the determination of the value-addition of the current irrigation water-use to the crop yields, the level of water-use efficiency, and the factors that explain this efficiency in the Scheme.
1.3 Research Questions
1. What is the response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme?
2. Is the use of irrigation water use in Mogotio Scheme economically efficient?
3. Which factors explain the Scheme economic irrigation water-
use efficiency?
1.4 Research Hypotheses
The hypotheses that formed the basis of the study were as follows:
1. There is no significant response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme
2. Irrigation water use in Mogotio Scheme is not economically efficient
3. There is no significant variation among the factors that determine the economic water-use efficiency in Mogotio Irrigation Scheme
1.5 Objective of the Study
1.5.1 General Objective
The overall objective of the study was to analyze the economic efficiency of irrigation water-use in Mogotio Irrigation Scheme.
1.5.2 Specific Objectives
The specific objectives guiding this study were:
- To determine the response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme
- To determine the economic efficiency of irrigation water-use in Mogotio
Irrigation Scheme
3.To examine the factors determining economic irrigation water-use efficiency of mogotio Irrigation Scheme
1.6 Justification and Significance of the Study
1.6.1 Justification of the Study
The study was prompted by a number of reasons. First, the evident threat of water scarcity to sustainable development at international, regional, and national levels has led to campaigns for integrated approach to water resources management (Hooper, 2003; SAEFL, 2002). These campaigns emphasize water-use efficiency. Equally, the emphasis laid on irrigation expansion by the macro-economic strategies further justify the need to improve the efficiency of irrigation projects and hence the study. These include the poverty alleviation, economic recovery and wealth and employment creation, as well as industrial transformation strategies.
Second, irrigation expansion is inevitable. Only 19.6% of the Kenya’s irrigation potential has been utilized so far (Republic of Kenya. 2007b), with more than half of the water withdrawal being used in the process. The corollary to this situation is that any measure of irrigation expansion will lead to a significant water deficit for other sectors. Yet, the current national approach is focused on exploiting the vast untapped irrigation potential, with disproportionate focus on the efficiency with which the current irrigation activities are undertaken. Since irrigation is water-intensive, this imbalanced emphasis may threaten the sustainability of both current and future irrigation projects as well as the expansion of the non-agricultural sectors.
Fourth, the national irrigation policy is still in its formative stages. For it to be appropriate, formulation and implementation of the policy needs to be backed by sound facts supported by empirical evidence (Rathgeber, 1997) that this study seeks to provide. The findings of this study will thus augment the formulation and implementation of this policy.
1.6.2 Significance of the Study
This study forms a point of reference for evaluating the efficiency of the current as well as future rice irrigation activities in the Scheme. It generates the empirical evidence required to facilitate the improvement of economic use of irrigation water in the Scheme, which will help improve the overall basin-wide and subsequently national water resource productivity.
Finally, the study is expected to provoke the analysis of similar projects in the country. This will facilitate the development and integration of best management practices in the irrigation water-use in such projects.
1.7 Scope and Limitation of the Study
1.7.1 Scope of the Study
The spatial delineation of this study was the analysis of economic efficiency at the Scheme level. The study was confined to the flood-irrigated rice cultivation activities in the nucleus region of the Scheme. Although irrigated horticultural crop production activities are also undertaken in the Scheme, these were excluded because their water abstraction methods were not adequately gauged and the quantity of water consumed was, consequently, difficult to determine. The rice cultivation activities in the out-grower region of the Scheme were excluded too due to inability to quantify their irrigation water input.
However, this study was limited to technical and allocative levels for the purpose of determining overall economic or cost efficiency. From classical economics, “management” is a basic variable in a production process. However, it was omitted in data collection and analysis because the variable had no empirically measurable indices. Secondly, since management underpins the decision-making in the allocation and utilization of the other factors of production, it was assumed to be adequately explained by the use of these factors. In addition, during analysis of efficiency, the variable “land” was eliminated due to strong positive correlation between land and the other factors of production.
1.7.2 Limitations of the Study
Lack of reliable time-series data on rice cultivation activities in the Scheme production limited the study to the use of cross-sectional data. Likewise, the limited period and funds allocated for the study restricted the number of variables of study to the farmers’ technical and socio-economic characteristics, input quantities and costs, and rice yields. In addition, limited finance did not allow a larger sample size for the study. The study was further limited by the inadequacy of published literature on irrigation in Kenya.
Other limitations were inadequate data on the quantity of on-farm water-use in the Scheme. Consequently, it was not possible to decompose the water-use inefficiency into water lost through the irrigation conveyance system, the field bunds, and inefficient field application. Similarly, on-farm water supply was assumed to be equitable among the farms.
1.8 The Study Area
The study area is located in Mogotio Division of Mogotio District in baringo county,
Kenya. It is situated in the nakuru –marigat highway Catchment that is drained by the The higher areas have shallow reddish-brown lateritic clay loams (red soils), while the low lands are impervious heavy montmorillonitic clays. Mogotio has bi-modal rainfall with peaks in April and November, a mean annual precipitation of 944.1mm, and a temperature range of 22ºC in July and 24ºC in
February (Chuaga, 1981).
(Source: NIB, 2008)
Water use in the Scheme is regularly monitored by use of gauges installed at the main canal headworks (water intake points on the river). As at the time of the study, installation of similar gauges further downstream was in progress. However, the structures were often vandalized by the irrigators during periods of water scarcity thereby hampering routine gauging of water distribution. River and canal discharges were recorded at the gauge stations and water-use in the farms monitored daily.
Figure 1
Figure 1. Schematic diagram of the water abstraction and conveyance system
(Source: Lebeau, 2007)
The choice of the study area was influenced by several factors. First, Mogotio is the oldest and largest public irrigation project in Kenya, upon which other projects. It is the most active irrigation area in mogotio, which is the largest river basin in the area in terms of mean annual discharge as well as percentage water abstraction (Republic of Kenya, 1992; NEMA, 2003). More than 90% of the water abstracted in the basin is already used in irrigating just over 40% of its irrigable potential. Further, irrigation is still expanding in the study area. Addressing irrigation water-use efficiency in Mogotio, therefore, has direct benefits to the area.
CHAPTER TWO
LITERATURE REVIEW
2.1 Introduction
The previous chapter gave an overview of the need for analysis of economic use of irrigation water-use in Mogotio Scheme. Investigating the efficiency contributes to the theory and practice of irrigation water management in Mogotio Scheme.
Figure 2
In the current chapter, the necessity and timeliness of this study are presented in the context of sustainable development. The relationship between this study and the information in the literature is provided, the distinction between the study and previous research explained, and the gaps identified in this respect highlighted. The chapter discusses these issues in relation to sustainable use of irrigation water in Mogotio Scheme.
2.2 Importance of Rice Farming in Kenya’s Economy
2.2.1 Agricultural Productivity and Kenya’s Economic Development
The declining agricultural productivity due to environmental degradation and population pressure on the limited natural resources requires innovative distribution and use of resources available to the agricultural sector (Todaro & Smith 2006; Rosegrant et al., 2001). In Kenya, this need is justified by the fact that agriculture forms the backbone of the country’s economy, with the gross domestic product (GDP) fluctuating in response to agricultural productivity. The GDP exhibits particular vulnerability during periods of low agricultural performance (Figure 2.1).
Figure 2.1: Kenya’s agricultural and GDP growth rate trends (1990-2000)
(Source: Republic of Kenya, 2002) for every 1% increase in growth of the agricultural sector (SRA, 2004).
2.2.2 Kenya’s Agricultural Productivity and Expansion of Rice Cultivation
It is generally agreed that the performance of Kenya’s predominantly rain-fed
agricultural sector has declined in the recent past (Oduol, 2006). Further, Jaetzold et al. (2007) describe the sector as highly vulnerable. The limited soil fertility, erratic rainfall, frequent droughts, ineffective land-use policies, declining arable land and increasing land fragmentation due to population growth have reduced the performance of the sector (Bruce, 2008).
Rice is one of the world’s three major cereal crops, the other two being maize and wheat. Globally, it is the leading cereal crop that is consumed as staple food by 2.7 billion people, providing 35–60 percent of the total calories (Guerra et al., 1998). The crop occupies one-third of the world’s total area planted to cereals, is the second most productive (Table 2.1), and the leading in yield stability (Figure 2.2), among the cereals.
Table 1:Global productivity trends for maize, rice and wheat (1966-2006)
| Crop | Mean Yield (kg ha-1) | Rate of gain (kg ha-1 yr-1) | |
| 1966 | 2006 | ||
| Maize | 2260 | 4759 | 62.5 |
| Rice | 2097 | 4235 | 53.5 |
| Wheat | 1373 | 2976 | 40.1 |
( Source: Cassman, 2008)
The fact that rice has sustained a steady lead in price among the three cereals globally between the years 2000 and 2008 (TIAPD, 2009) further calls for its increased production in the regions that have the comparative advantage to do so to help achieve global food security and economic development.
Kenya has a declining arable land (Oduol, 2006). Its low agricultural productivity therefore calls for expanded cultivation of crops with high yields and socioeconomic value. Rice is such a crop with high productivity and with increasing demand in the country.
2.2.3 Irrigation Water-Use and Rice Cultivation
The prospects of irrigation in revitalizing agriculture have been demonstrated by the output derived from the limited area exploited so far. Irrigation accounts for 40% of the global food from only 17% of the cultivated land. In Asia, yields of most crops have increased by between 100–400% due to irrigation, with subsequent reduction in food prices (IPTRID, 1999). In fact, the Food and Agriculture Organization (FAO) estimates that irrigated land will increase globally to 209.5 million hectares come 2010, up from 186 million hectares in 1994 (Yudelman, 1994).
Most of the world’s rice is grown in Asia, where more than 80 percent of the developed freshwater resources are used for irrigation purposes and about half of the total irrigation water is used for rice production (Dawe et al., 1998; Bhuiyan 1992). The dominant practice in rice cultivation is flood irrigation. Under this system, the rice is grown in paddies that are maintained in flooded field conditions throughout the crop establishment, as well as crop growth and development stages. The flooding only stops when the crop starts maturing. In Kenya, the paddies are kept flooded even during land preparation period.
The objective of wet land preparation is to kill weeds, reduce the soil clod size to the required tilth, and achieve the desired slope for proper distribution of water and fertilizer. It involves ploughing, pulverizing and levelling the flooded land.
2.3 Role of Water-Use Efficiency on Sustainable Irrigation
2.3.1 Water Scarcity Trends and Sustainable Irrigation
Forecasts indicate that severe water shortages will be witnessed on regional or even global scales in the twenty-first century (World Water Forum, 2000). At the same time, population explosion will stimulate additional demands for food and fibre production as rural people flock into the cities. In this respect, Falkenmark (1997) reported that 55 percent of the global population is consigned to either water stress, or severe water stress, merely by virtue of population growth. Table 2.2 gives the world trends and projections in sectoral water utilization.
Table 2.2: World trends and projections in population and sectoral water-use
| Sector | 1900 | 1960 | 1995 | 2010 | 2025 |
| Population (million) | 3,029 | 5,735 | 7,113 | 7,877 | |
| Irrigated land (106ha) | 47.3 | 142 | 253 | 288 | 329 |
| Agricultural use (km3/yr) | 513 | 1,481 | 2,504 | 2,817 | 3,189 |
| Municipal use (km3/yr) | 22 | 118 | 344 | 472 | 607 |
| Industrial use (km3/yr) | 44 | 339 | 752 | 908 | 1,170 |
| Total use (km3/yr) | 579 | 1,968 | 3,788 | 4,431 | 5,235 |
(Source: Pereira, 2005)
The table shows a remarkable rise in water-use for all the sectors. Of immediate concern is the leading margin by which agricultural water-use is increasing in tandem with increase in population, and hence the need for water conservation.
2.4 Types and Measures of Efficiency
2.4.1 Types of Efficiency
Measures of efficiency include technical efficiency, scale efficiency, allocative efficiency, and productive (also termed cost or economic) efficiency. Technical efficiency of a production process refers to the physical or functional relation between resources and outcome. A technically efficient position is achieved when the maximum possible improvement in outcome is obtained from a set of resources. A production process is said to be technically inefficient if the same (or greater) outcome could be produced with less of at least one of the inputs used (Palmer & Torgerson, 1998).
Technical efficiency cannot, however, directly compare alternative interventions, where one intervention produces the same (or better) outcome with less (or more) of one resource and more of another. Since it is possible to use different combinations of inputs to produce a given level of output, the choice between input combinations is based on the relative costs of these different inputs. In this case, productive efficiency is a preferable measure.
Allocative efficiency reflects the ability of a firm to use inputs in optimal proportions, given their respective prices and the production technology. It takes into account not only the productive efficiency with which resources are used to produce outcomes but also the efficiency with which these outcomes are distributed among the community. Allocative efficiency is achieved when resources are allocated so as to maximise the welfare of the community.
This study sought to analyze irrigation water use within a one particular crop (rice) in one sector (agriculture). The interest of the study was to determine highest level of output that the farms could have produced given their combination of resources. Technical efficiency measure was, therefore, adopted. The approach of variable returns to scale was adopted due to the supposition that farmers operate under imperfect competition and financial constraints.
2.4.2 Efficiency Measurement Concepts
A production process involves use of a combination of inputs in order to obtain an output. For instance, the output of rice or yield requires inputs in form of land, irrigation water, labour and working capital. Analysis of efficiency of such a production requires a methodology that incorporates all the specified inputs.
The two main objectives of efficiency measurement are input minimization and output maximization. Coeli et al. (1998) describe these objectives as input-oriented and output-oriented measures respectively. The input-oriented approach attempts to expose by how much the input quantities can be proportionally reduced without changing the output quantities produced. On the other hand, the output-oriented approach seeks to determine by how much the output quantities can be proportionally expanded without changing the input quantities used. The input approach involves managing the production inputs in such a way as to optimize output, while the output orientation involves managing the output so as to optimize the use of inputs. Since farmers can control the management of the factors of production more easily than the output, this study adopted the input approach to the efficiency analysis.
( DEA ).
2.5 Theoretical Background to Water-Use Efficiency
There is a positive correlation between economic development and water consumption (Environmental Protection Authority, 2007). This implies that as an economy shifts from agriculture to expansion of industrial and service sectors, water utilization too increases. But water supply is either constant, or declining. It can, therefore, be concluded that economic development leads to redistribution of water among socio-economic sectors and hence intensifies water scarcity per sector. Efficient water-use thus needs to be integrated into sustainable development planning.
At sectoral level, smallholder farming households exhibit significant variability of resources available on the farm such as land, water, and labour (Ahmed et al., 2006; Shisanya, 1996). Consequently, farmers face considerable challenge in identifying the most appropriate resource and output mix as well as practices that minimize costs and risks, and/or maximize profits. The limitations in these planning-related factors have been reported to cause the unsatisfactory performance of irrigation development and management projects in Sub-Saharan Africa (IWMI, 2005). Farmers need to incorporate optimal use of resource productivity into the planning and decisionmaking processes in order to improve their economic performance.
2.6 Definition of Water-Use Efficiency Terms
Several authorities have applied the concept of efficiency to water resource use. Subsequently, irrigation efficiency has been given several definitions based on water use, energy use, labour and capital investment, and how these aspects relate to production and profitability. It should, however, be noted that there is no single definition that covers all aspects of irrigation efficiency (Pereira, 2005). Appendix II gives the various technical concepts of water-use efficiency, and how they relate to each other.
There was inadequate gauging of irrigation water conveyance, distribution and use in the Scheme. Consequently, there was limited data on irrigation water use. This study therefore used economic approach to analyze water-use efficiency.
2.7 Empirical Studies on Resource-Use Efficiency
Given the declining trends in the availability of resources, the efficiency with which they are used has been the focus of several empirical studies. This section reviews some of these scholarly works from the literature. experimental research where the factor under analysis is varied with all other factors held constant. The current study used an integrated approach where all the factors of production were taken into account, which reflects the real situation faced by the farmers in their fields. It used secondary data to determine the impact of the quantity of flood irrigation water used, among other production factors, on the yield of rice in
Mogotio.
An analysis of Kenya’s agricultural sector productivity between 1960 and 1990 using
time-series data to generate the Cobb-Douglas production function revealed that agricultural land as well as land productivity was declining (Juma, 1994). The study recommended the need to improve land productivity, but fell short of identifying practical ways of achieving this improvement. Unlike Juma (1994) , who relied on time series data, the current study used cross-sectional data. Time series data are appropriate for analyzing change in parameters over time. Comparing performance of farms within a season requires cross-sectional data. The current study used crosssectional data approach since it involved comparing the differences among irrigators within a common season of irrigation. Further, this study suggested how to improve the productivity of the national agricultural sector through efficient use of irrigation water.
Kamau (1981) studied the productivity of land and labour in the small- and largescale coffee farms in Kiambu District of Kenya by using the Cobb-Douglas production function to estimate the marginal value product. He found that large-scale farms were better at optimizing farm mechanization and hence achieving higher productivity due to higher technical efficiency than the small-scale farms. He suggested the need for improving the productivity of the factors of production. The current study identified irrigation as a critical means of improving land productivity, and addressed water-use efficiency as one way of sustaining the productivity. Effective intervention demands identification of the factors determining the low productivity of the inputs of production.
To investigate the factors determining the demand for life insurance in Canada, Fu (2004) used the Tobit analysis in order to examine the quantity of life insurance and the probability of purchasing. Income, marriage, age, educational level, number of earners, family size, and home ownership were found to be positively related with the demand for insurance. Regarding the probability of purchasing, the respondent’s after-tax income had the highest elasticity of demand. The current study adopted similar methodology to examine the relative importance of social and economic characteristics of irrigators in determining their use of irrigation water.
2.8 Gaps Identified in the Literature
Expanding the cultivation of high-productivity crops such as rice holds the key to improving agricultural productivity. In addition, innovative use of the limited water resources available to the agricultural sector is necessary to mitigate the vulnerability of Kenya’s GDP to the predominantly rain-fed sector. This involves improved efficiency of water use. In this respect, the following were the gaps identified in the literature which this study addressed:
i) In order to effectively improve the water resource productivity, there is need to determine the contribution of the quantity of water used as a factor of rice production in the Scheme; ii) Irrigated agricultural production is a function of complex interactions among water, land, labour, and capital. Analyzing economic efficiency of irrigation water-use needs integrated approach that incorporates all these factors.
2.9 Technical and Socio-economic Factors of Water-Use Efficiency
2.9.1 Quantity of Irrigation
In this study, water-use efficiency as a parameter is a ratio of the quantity of rice output to quantity of water input. Water-use efficiency is expected to be higher when less water is used to produce a given quantity of output than when more water is used. Since there were no gauges for irrigation water-use at the farm level, the water abstracted for irrigation from the rivers was used. The water supply was assumed to be equitable and proportional to land area. Conveyance and distribution water losses were thus lumped together with the application losses. There was one point of abstraction of water from each of the two rivers. The canal discharge at each abstraction point was monitored throughout the season and daily records taken in cubic metres per second. The study summed up these daily discharges, recorded for the entire rice season, to obtain the total Scheme irrigation water-use. In this study, it was hypothesized that excess water is used to produce output in the Scheme. The variable, measured in cubic metres, was theorized to be negatively correlated with efficiency.
2.9.2 Labour
The factors of labour that affect irrigation water-use efficiency include its cost, availability, and reliability (Aqualink, 2006). The intensity of use and hence impact of labour is a function of technology, with more advanced (mechanized) technology being less labour-intensive. In Mogotio, the abstraction, conveyance and distribution of irrigation water are accomplished by gravity flow. However, the conveyance system is an elaborate network of open earth canals. In effect, therefore, the subsequent siltation and weed congestion in the canal network renders the operation and maintenance of the irrigation and drainage infrastructure labour-intensive. In addition, labour is used in the crop husbandry activities such as seedbed preparation, levelling, weed control, application of agro-chemicals, bird-scaring, and harvesting. These activities directly affect the quantity of output produced as well as on-farm water management and consequently the water-use efficiency. Considering the labourintensive technology used in the Scheme, the labour was expected to be positively correlated with water-use efficiency, and was quantified in terms of man/days by enumerating all the family members who can provide labour.
2.9.3 Land Size
Land is a basic input in an agricultural production process. Farm size in respect of this study refers to a measure of the area of the land allocated to rice under irrigation during the period under study. During water conveyance, one has to significantly fill up the primary and secondary canals to enable water flow into the fields downstream, irrespective of the number of such fields irrigated. Conveyance losses at the level of these canals are, consequently, dependent more on the duration of conveyance than on the command area downstream. If conveyance losses are prorated per acre of land irrigated, then more land under irrigation is more efficient than less land irrigated through a given canal network. The larger the area being irrigated the better the economies of scale. Farm size was, therefore, hypothesized to be positively correlated with water-use efficiency due to economies of scale. The variable was measured in acres of rice irrigated.
2.9.4 Working Capital
This variable represents the expenditure incurred by the farmer in procuring inputs and services that were used in the production process. The working capital included the cost of labour for land levelling, weeding (Plate 3.2), transplanting, bird-scaring, and harvesting. Other labour expenses included application of fertilizers, herbicides, insecticides, and fungicides. Also included in this variable were costs of canal operation and maintenance, land preparation, seed, fertilizer, herbicide, fungicide, gunny bags, and post-harvest handling of the harvested rice. The canal operation and maintenance cost included the cost of water. The costs were measured in Kenya shillings. Since high capital intensity increases productive efficiency, this variable was hypothesized to have a positive correlation with water-use efficiency.
2.9.5 Age of the Farmer
Age of farmer, measured in years, is important since it may influence the farmer’s
decision-making on the input allocation as well as the intensity of input use (Oduol, 2006). This can be attributed to the positive correlation between age and accumulation of knowledge through experience. Moreover, where there are conflicts over water-use, older farmers tend to have more restricted access to water than their younger and more energetic counterparts. Those with greater access to water irrigate more frequently and luxuriously than the less privileged ones. The study considered as inefficient the luxurious use of water. Farmer’s age was therefore expected to be
positively correlated with less water-use, and hence greater efficiency. The age recorded was the age attained as of the date of interview.
2.9.7 Gender of the Farmer
Gender disparity has been reported regarding rights of access to productive resources such as water (Oha, 2007; du Guerny, & Topouzis, 1996). Further, women are disproportionately represented among the poor, with economic and social inequities preventing them from accessing educational opportunities, productive resources such as land, and hence credit (IPTRID, 1999). Access to information due to education increases rate of technical change. The consequence of gender disparity in access to credit and education is the limited disposable income and increased risk averseness that may lead to reduced intensity and efficiency of input utilization among femaleheaded households.
In the Scheme, however, access to farming credit is based on tenancy licence, to which men and women have equal rights. The only gender disparity of relevance to water-use efficiency lies in access to irrigation water during periods of water shortage. Women were expected to be disadvantaged in the event of water conflicts among the irrigators. It was hypothesized that women use less water, and are hence more water-efficient than men. Dummy variables were introduced to measure this variable, with 1 indicating “male”, and 2 indicating “female”.
2.9.8 Farmer’s Level of Education
This variable affects the literacy and technical skills and hence rate of adoption of technology. Since the benefits, intensity, and methods of input-use require technical skills, high level of education improves the farmer’s capacity to seek and utilize
information. Education, thus, forms the basis for technical change, with positive correlation with technical efficiency (Myint & Kyi, 2005). In fact, Hayami and Ruttan, (1985) associated high level of education with increased farm productivity due to improved quality of management. They argued that inadequate education increases conservatism, limits the capacity to absorb risks, and increases fear to invest in production resources. The variable was, consequently, expected to be positively correlated with efficiency of irrigation water use. The study expected a significant difference between the farmers with at least formal education and those without, than difference between the various levels of formal education. Farmers with at least formal education were expected to be more efficient in using irrigation water than those without. The variable was measured by using dummy variables, with 1, and 2, indicating formal education and none respectively.
2.9.10 Farmer’s Irrigation Experience
This variable refers to the skills on irrigation accumulated overtime by the farmer. More experience implies that the irrigators understand the purpose of irrigation, and therefore, apply the required amount of water at the right time. Experience, measured in number of years as an irrigator, is expected to contribute positively to irrigation efficiency. In the study, dichotomous variables were used to measure farmer’s irrigation experience. In this case, 1 was used to indicate “1-3 years”, 2 for “4-6 years”, 3 for “7–9 years”, and 4 for “10 years and above”.
2.9.11 Farm Position along the Canal
The quantity of irrigation water used is affected by the location of the farm along the canal (Ragwa, 2002). Due to the upstream priority enjoyed by the farms located at the head of the canal, such farm irrigators may over-irrigate by topping up their fields more often whenever there is water in the canal, thus creating shortage downstream.
On the other hand, those farms located at the tail-end along the canal tend to underirrigate due to less privilege in terms of access to water. Occasionally, though, overirrigation may occur at the tail-end as an insurance against anticipated future water shortages due to inadequate water supply or due to interference from upstream irrigators. In the latter case, fields are topped beyond the required depth as an insurance against water shortage in the subsequent irrigation rotations.
The hypothesis regarding this variable was that water-use efficiency increases downstream. In measuring this variable, dummy variables 1, 2, and 3 were used to represent “head”, “middle”, and “tail”, respectively.
2.9.12 Duration of Land Preparation
Land preparation for rice cultivation in the Scheme involves flooding to soak the soil, followed by rotavation (paddling) and levelling the paddled land under water. The levelled land is then maintained under water (topping) for weed control until rice transplanting is done. The planned duration can take months depending on the acreage, as well as availability of water and land preparation machinery. This period is set in order to allow all farmers in a WMU to prepare land so that seed nurseries are set at the same time for uniform crop and water management. The actual duration taken depends on the farmer’s capital outlay and experience, but cannot go beyond
the planned period due to restriction by the crop programme. Longer duration implies more water-use for topping of the rotavated field, which does not necessarily add value to the rice output. The duration, measured in weeks, was therefore hypothesized to have a negative impact on water-use efficiency.
2.9.13 Irrigation Water Conflicts
Conflicts over natural resource use occur when the rate of use is faster than any combination of natural replenishment, technological advances in resource-use efficiency, and institutional capacity to regulate resource use. Water-use conflicts lead to artificial water shortages, reduce equitable distribution of water among the irrigators, and often lead to over-irrigation as an insurance against anticipated lack of water in subsequent water supply rotations. Conflicts were therefore hypothesized to be correlated with less efficient water use. This variable was measured through use of binary variables 1, as code for “yes”, implying frequent occurrence of conflicts
among the water users; and 0 otherwise.
CHAPTER THREE
DATA AND RESEARCH METHODOLOGY
3.1 Introduction
The previous chapter highlighted the relevance of the study objectives in the context of the current practice and theory of irrigation. This chapter gives the design of the study by describing the methodologies used in order to achieve these objectives. Section 3.2 outlines the sampling procedures, while section 3.3 focuses on the data collection. The definitions of the data collection variables and data analysis are presented in sections 3.4 and 3.5 respectively.
3.3 Data Collection
Administering questionnaires and oral interviews data were collected on rice production and irrigation water-use for the 2007/2008 season. The study used both primary and secondary data collected by conducting direct personal interviews to the sample respondents. A structured questionnaire (Appendix IV) was used as a tool for this exercise. Such a tool prevents observation bias. The data collection was carried out in September and October of the year 2008.
The data collection was preceded by a public-relations bulletin and training of the interviewers. A notice was given and public awareness meetings held in the respective sections of the Scheme in order to inform the farmers about the objective of, as well as the legal authority for conducting the field survey. The meetings further explained ultimate use of the data and how the irrigators would benefit from the study, and underscored the need for accurate information. Farmers were also assured of the confidentiality with which the information given would be treated. The said notices and meetings helped to achieve the farmers’ cooperation during the subsequent interviews.
The sensitization meetings were then followed by pre-testing of the questionnaires in order to ensure that the required information was adequately captured. After pretesting, the reviewed questionnaires were then used to conduct field survey through direct personal interviews (Plate 3.1). Secondary data were collected from relevant institutional sources such as the National Irrigation Board; Agricultural Information
Centre, Kenyatta University, University of Nairobi, Kenya and Agricultural Research Institute. Other sources included the Ministries of Agriculture, Water and Irrigation, Planning and National Development, as well as the Internet.
Figure 3.1: Location and spatial distribution of survey sites
(Source: Author, 2008)
3.4 Definition of the Variables
3.4.1 Dependent Variables
There were three dependent variables in the analytical models. In the determination of the significance of the response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme, the dependent variable was the quantity of rice harvested per farmer. This variable was measured in kilograms as the sum of the quantity of rice harvested per farm family in the Scheme in the 2007/08 cropping season. Farmers were asked the total number of standard bags of rice harvested. Using the standard weight per bag in the Scheme, the total kilograms of the harvested rice were computed and recorded as the rice output.
3.4.2 Independent Variables
The study collected data on four main explanatory variables in the determination of significance of the quantity of irrigation water used as a rice production factor in the Scheme. These were the quantities of irrigation water, land, working capital and labour. The weighted values of rice output, water, land, working capital, and labour inputs were used in determining the economic water-use efficiency.
The variables used in the examination of the factors that determine water-use efficiency in the Scheme included farmer’s age, farmer’s level of education, gender of
farmer, and farm position along the canal. Others were the planned and actual durations of land preparation, reason for actual duration of land preparation, water shortages, water conflicts among the irrigators, drain-water use, reason for depth of irrigation water used, and impression of operation and maintenance fee charged.
3.5 Data Analysis
3.5.1 Introduction
The essence of data acquisition is to transform it, by analysis using economic principles, into useful information from which inferences are drawn through description, prediction and explanation. These inferences are then used to support the identification of the potential alternatives that facilitate decision making in managing or controlling the phenomenon under study.
There are different types of analytical methods, each one suitable for use under specific sets of assumptions. The choice of a method required depends on the structure of the data analysis as well as the nature of the design technique. Familiarity with the structure and procedures of the analysis helps one to know that a design will be effective (Rudestam & Newton, 2001). This study used economic analytical methods. These were descriptive statistics, regression, correlation, and data envelopment methods of data analysis. In descriptive statistics, graphic displays were used to illustrate key features of the study variables (Martin & Larson, 2006).
Regression is defined as a quantitative expression of the basic nature of the relationship between the dependent and independent variables (Webster, 1995). It measures the direction of movement of the dependent variable in response to changes in the independent (the explanatory) variable. In addition, it reveals the amount by which the dependent variable will change given a one-unit change in the independent variable. Correlation complements regression by measuring the strength of the relationship between the dependent and the independent variables or the degree to which the two variables change together.
As analytical tools used to identify and measure the statistical relationship between variables, regression and correlation are useful in estimating parameters of a population based on the study of its sample. The power of these tools lies in their ability to help identify, test and validate the functional relationships between variables (Warner, 2004). Such relationships facilitate policy evaluation necessary for identifying the best practice approaches to natural resource management. This was found appropriate for the study since the findings are expected to facilitate the effective formulation and implementation of the critically needed irrigation policy in Kenya.
used in the study are summarized in Table 3.2.
Table 3.2: Data analysis
| Objectives | Activity and Variables | Statistical Analysis |
| To determine the response of rice yields to the quantity of irrigation water used in Mogotio Irrigation Scheme | -Compute the quantities of inputs used ( water, land, working capital, labour) and their log values per farmer; -Compute the quantity of rice harvested and its log value per farmer; -Generate a Cobb-Douglas production function for rice in the Scheme | -Descriptive statistics; -OLS regression analysis using SPSSPC software; Correlation analysis |
| To determine the level of economic efficiency of irrigation water use in Mogotio Irrigation Scheme | -Compute input technical efficiencies (TEVRS) from respective input quantities; -Compute input allocative efficiencies (AEVRS) from respective input quantities; -Compute overall economic or cost water-use efficiency (CEVRS) from the product of its TEVRS and AEVRS | -DEA analysis using EXCEL-PC software; -Descriptive statistics |
| To examine the factors that determine economic efficiency of irrigationwater use in Mogotio Irrigation Scheme | Determine the variation in the significance among factors determining the technical efficiency in the Scheme: drain water re-use, conflicts among irrigators, planned and actual duration of land preparation, gender of farmer, farmer’s level of education, position of farm on feeder canal, impression of operation and maintenance fee charged, age of farmer, water shortages, reliability of water supply, and availability of water | -Censored Tobit regression analysis using STATA-PC software; -Descriptive statistics |
(Source: Author, 2008)
CHAPTER FOUR
RESULTS AND DISCUSSION
4.1 Introduction
In this chapter, the findings of the study are presented and discussed. Section 4.2 of the chapter deals with determining the significance of quantity of irrigation water used as a factor of rice production in the Scheme. Section 4.3 presents the analysis of economic water-use efficiency. Finally, section 4.4 dwells on the determination of the factors that explain the Scheme economic water-use efficiency.
4.2.3 Discussion
From the result of this analysis, it can be observed that the quantity of irrigation water, labour and capital used have positive impact on rice output in the Scheme. The impacts, however, are insignificant for water and labour, but significant for capital at 95% confidence level. Since the impact of the quantity of irrigation water used on rice yield was insignificant at 0.05 level of significance, there was no sufficient evidence to reject the null hypothesis.
On the basis of the data obtained from the sample of 121 Scheme irrigators, the regression coefficients (production elasticities of inputs) were 0.099, 0.294, and 0.510 for water, labour, and working capital respectively. Two principal inferences can be drawn from the production function depicted by Equation (4.3) , both related to the regression coefficients. The first one is linked to the relative importance of the factor inputs used in Mogotio Irrigation Scheme. A 0.51% change in output would be observed if working capital changed by 1% with labour and water held constant. Similarly, an equivalent change in labour would change rice output by 0.294% with all other inputs held constant; whereas, a 1% change in water would change the output of rice by only
0.099%, ceteris paribus. Considering the three inputs therefore, rice output in the Scheme is most responsive to capital, and least responsive to quantity of irrigation water under the current level of technology.
Statistically, there is no significant relationship between the quantity of irrigation water as used, and the rice output in the Scheme. At the 0.05 level of significance, αvalue should be 0.05 or less to imply significant effect. However, the α-value for impact of irrigation water was 0.657, implying insignificant effect. The low response of output to water suggests that water-use in the Scheme is below its productive potential. Comparable observations on irrigation efficiency in paddy fields in the Lower Mekong Basinwere made by (Phengphaengsy & Hiroshi, 2006) on total and input factor productivity analysis of poultry production in Khorasan Province, Iran.
Alternatively, the water has probably attained its maximum factor productivity in the
Scheme and, at the current technology, is in the third stage of the production function. In this stage, both the average and marginal productivity are positive but are declining. Precise explanation of the current water use in the Scheme thus requires determination of the water-use efficiency.
. The solution to improving the productive capacity of the resources thus lies in technical change rather than physically expanding their use.
The above analysis and inferences only refer to the functional relationship between the factors of production and the output. They do not, in any way, prove whether the water resources are optimally utilized or not. In addition, the least squares econometric models employed in this analysis have the limitation of assuming that all the DMUs (farms) studied are fully efficient (Coeli et al., 1998). This, however, is not always the case. In order to address this limitation, an analysis of the efficiency of use of the water resources was undertaken, under the subsequent objective.
4.3 Economic Efficiency of Irrigated Rice Production
4.3.1 Irrigation Water Use
The Scheme operated a number of check points for monitoring irrigation water flow between the point of abstraction from the rivers (the headworks) and the farms. However, there was inadequate gauging and inconsistency in the data collection due to frequent breakage of the gauges by vandals. The only guarded structures are those installed at the headworks. The only reliable data, therefore, were those of abstraction at the Nyamindi and Thiba headworks, where records were maintained of the daily water abstraction.
The water abstraction was governed by the on-farm water requirement as well as the weather conditions. Irrigation was only used to top up the deficit created by severe weather and crop water demand.
The functional relationship among these three parameters implies that the cost efficiency of rice production in the Scheme can be significantly improved more by improving the technical than allocative efficiency. The cost of production could also be reduced, though marginally, if allocative inefficiency were removed. Based on the results from sample, there was no sufficient evidence to reject the null hypothesis.
The results of this study are consistent with empirical results found in literature.
Ahmed et al. (2007) reported 56% on-farm water-use efficiency in the public irrigated Schemes in the River Nile State of Sudan. Similarly, system-wide and country overall irrigation efficiencies have been reported by Guerra et al. (1998) as indicated in Table 4.5 below:
From Table 4.5, the reported overall irrigation efficiencies range from 30% to 65%. Although the technologies used are not indicated, these figures show remarkable overuse of water, and this probably explains why irrigation consumes more than 80% of abstracted water in Asia (Dawe et al., 1998; Bhuiyan 1992). In addition, it is shown that lower efficiency was observed during wet than during dry seasons in
Thailand. This is probably due to excess availability of water during wet season as well as its scarcity during dry season. Irrigators therefore place greater value for, and economize water use during dry season than they do in wet season.
Table 4.5: Overall irrigation efficiencies of some irrigation systems
| Country/Irrigation system | Overall irrigation efficiency (%) | Remarks |
| Indonesia | 40-65 | |
| Malaysia/Kerian Irrigation Scheme | 35-45 | Command area = 23,560 ha |
| Thailand/Northern, Mae Kiong, Chao Phraya | 37-46 | Wet season >12,800ha |
| 40-62 | Dry season >12,800ha | |
| Canal systems, northern India | 38 | |
| Kamataka state, India | 30 |
(Source: Guerra et al., 1998)
The level of inefficiency revealed by these results lead to the may imply that the inefficiency is due to water resource overuse, a common feature of common-pool resources. Such resources are characterized by low excludability, and high rivalry. In order to assure the sustainability of such resources, Ostrom (1990) recommended eight principles. These principles can be summarized into delineation of project areas based on hydrological rather than administrative boundaries, effective regulation, and integrated resource management.
4.4 Factors that Determine Economic Efficiency of Irrigated Rice Production
4.4.1 Summary of Socio-Economic Characteristics
The main economic activity in the Scheme is farming, with respondents fully dependent on farming as their main occupation, against respondent who relied on business. The limited variability in this factor among the irrigators led to its exclusion from subsequent analysis. Similarly, the farmers had more than ten years of experience in irrigation farming, and the variable was excluded from further analysis due to its limited variability among the irrigators.
Household size ranged from 2 to 38, with a median size of 8. Labour in the Scheme was found to be fully commercial, even at household level. In addition, household access to labour depended on capital rather than household size. This variable therefore had no impact on household labour productivity, since household size only affected labour availability at the Scheme-, but not household levels. Consequently, this variable was eliminated in the subsequent analysis.
The land-use results reveal a number of factors regarding the land resource in the Scheme. These include the availability of the resource, importance of agriculture to the Scheme community, scale of farming activities, and potential for horizontal irrigation expansion. Additional revelations are the importance of irrigation in the Scheme farming activities, and the importance of rice cultivation to the local community.
Regarding the land resource availability in the Scheme, open land frontier has been closed since there is no fallow land available. This reflects similar observations regarding the Sub-Saharan Africa and Kenya (Reardon et al., 1996; Lele & Stone, 1989). This implies that irrigation expansion in the study area will involve intensification (vertical expansion) of the already used land rather than the horizontal expansion of the cultivated land. In addition, based on the mean land holding, the Scheme is generally composed of small-scale farmers. The farming activities rely on irrigation and rice is the main crop grown. Since the rice is grown for commercial purposes, the farmers can thus be described as commercial small-scale.
The remaining factors showed sufficient variability to warrant further analysis. These were the position of farm, age of farmer, male gender, planned and actual durations of land preparation, water conflicts among the irrigators, frequency of water shortages, and formal education. Others were drain water re-use, availability of water in the canal, reliability of water supply, and cost of operation and maintenance fee charged. In this analysis, the above factors were used as the independent variables, and technical efficiency at variable returns to scale used as the dependant variable.
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
Several conclusions can be drawn from the study. First, there is no significant impact of the quantity of irrigation water used on the rice output. No further significant increase in rice output is expected by using more water on the area currently being cultivated since the farms were operating at decreasing returns to scale. The water has almost attained its maximum productivity in the Scheme. Consequently, there is need to reduce the quantity of irrigation water used for rice cultivation in the Scheme.
In addition, the farming activities are basically small-scale with resource constraints since the Scheme has reached its cultivatable horizontal land frontier in addition to the increasing water scarcity. Expansion of irrigation therefore requires improving land and water productivity. This requires investing in technologies that reduce wateruse on rice, as well as improving the land productivity. This will help improve output through vertical irrigation expansion.
Whereas these results are commensurate with similar results elsewhere in the world, Kenya’s fast-increasing water poverty and the critical role of irrigation in revitalizing its agriculture warrant serious remedial measures. The results show that there is potential for improving water productivity in the Scheme through technical change.
The factors with significant effect on technical efficiency of irrigation water-use efficiency in the Scheme included the actual duration of land preparation, water conflicts among irrigators, drain water re-use, and availability of water in the canal. The effects of these factors were significant at 0.05 level of significance. Actual duration of land preparation and availability of water in the canal improved, while conflicts and drain water re-use reduced water-use efficiency
5.2 Recommendations
Based on the observed inefficient water-use, the study recommends both technical and institutional changes in order to sustain irrigation development in Mogotio irrigation Scheme. The technical changes include agronomic and engineering or infrastructural interventions.
Dry land preparation will help save the water that is currently wasted on weed control prior to transplanting. Heavy clay soils that characterize Mogotio rice fields have limited workability since they are often too hard when dry, or too heavy when wet. The range of soil moisture that facilitates dry ploughing of such soils is therefore limited. However, this workability can be improved significantly if farmers incorporate rice straw in form of compost manure into the soil. Equally, the rice crop can be rotated with dual purpose (commercial-cum-subsistence) leguminous crops such as soybeans and green grams. The impact of such crops may take more than a season to realize, and the desired outcome too may be gradual, though.
There is need for adjusting the Scheme cropping pattern by the farmers, IWUAs, and the management in order to improve water-use efficiency for rice cultivation. The rice crop programme in the Scheme is limited by climate such that the Scheme has not been able to take advantage of lower water demand periods such as the long rains for crop use. Other adapted crops should be grown during this period in order to reduce the pressure on water during rice crop season. In addition, research can be done on the adoption of more water-efficient rice varieties to replace the current ones.
The engineering methods include: construction of large-scale water storage infrastructure by the government, canal lining and installation of water control structures by the government, re-use of drain water by the farmers and the management, and installation of gauges along the conveyance and distribution canal network by the management.
5.3 Suggestions for Further Studies
From this study, it has emerged that effective mitigation of the Scheme irrigation water-use inefficiency requires additional research work. This will help identify the sources of inefficiency along the supply-utilization continuum, resource management, and sustainability. The following are the suggested areas for further research:
Analysis of water conveyance efficiency in Mogotio Irrigation Scheme. This will help decompose the water-use inefficiency into inefficiencies due to conveyance and distribution as well as those due to on-farm water management for effective intervention.
Analysis of impact of non-flooding irrigation techniques on the yield and quality of rice in Mogotio Irrigation Scheme. This will help reduce the proportion of water allocated to rice cultivation so as to expand irrigation of other crops as well.
Determination of factors affecting the effectiveness of participatory irrigation management in Mogotio Irrigation Scheme. This will help identify priority areas of investment in public-private sector partnerships for sustainable Scheme irrigation management.
REFERENCES
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Water Use Efficiency in the Public Irrigated Schemes in the River Nile State of Sudan”. Conference on International Agricultural Research for Development.
University of Göttingen, October 9-11.
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APPENDICES
I: Planned Smallholder and Government-Managed
Irrigation Schemes
| ( |
| Source: Republic of Kenya, 1992 |
| ) |
PART I: FARMER/IRRIGATOR RESPONDENTS
A: GENERAL INFORMATION
Date of interview……………………….……………………………………… Name of interviewer…….…………………………………………………….. Time started……………….…………………………………………………… Time completed……………………….……………………………………….
B: GEOGRAPHIC LOCATION
Farm location: UTMX………….…UMTY………………. Altitude…………
C: IDENTIFICATION OF THE IRRIGATOR
Name of respondent………………………….………………………………… Name of farmer………………….…….……………….………………………
D: FARMER’S SOCIO-ECONOMIC BACKGROUND
Age ……
Gender of farmer (1) Male; (0) Otherwise ………..
Level of education: (1) At least formal education (0) Otherwise
Household size …………………………………….…………………..
Do you have any non-farm income?: (1) Yes (0) Otherwise
Number of years in irrigation farming (1) 1-3 (2) 4-6 (3) 7-9 (4) 10 and above
E: HYDROLOGIC PARTICULARS OF THE FARM
Section (1) Tebere (2) Mogotio or Nguka (3) Thiba (4) Wamumu (5) Karaba
Unit/Block Name…………………………………………………………..….. Feeder-Canal Name…………………………………………………… ………
Water User Identification Number…………………………………………….
Location of the farm on the feeder canal:
(1) downstream (0) otherwise
F: IRRIGATION WATER MANAGEMENT
Water use during land preparation
The planned period of land preparation. ————-weeks
Actual duration taken to complete land preparation. ———-weeks
Reason(s) for actual duration of land preparation
1 = availability of water in the canal; 2 = followed the usual practice of soaking the field while waiting for seedlings to be ready; 3 = other (specify)
Water use during the crop growth and development
How did you decide on the amount of water to use in the farm?
= reliability of water supply within the irrigation system; 2= depth of water necessary to smother weeds; 3= other (specify)
What is your view of the operation and maintenance fees charged? 1 = high; 0 = otherwise
How frequently did other farmers interfere with the irrigation schedule?
= frequent; 0 = infrequent/otherwise
Did you frequently lack water as a tail-end farmer along the canal?
= yes; 0 = otherwise
Do you irrigate using drain water? 1 = yes; 0 = otherwise
G: LAND-USE IN 2007
| Agricultural use | Non-agricultural | Total | |
| Irrigated | Rain-fed | ||
H: YIELDS OF RICE HARVESTED IN THE SCHEME IN 2007
| Total no. of bags harvested | Standard weight per bag (kgs) | Total weight of rice harvested | Average weight of rice harvested per acre (kgs) |
I: LABOUR USE
| Activity | No. of people | No. of days | Daily wage rate (KShs) | Total cost ( KShs ) |
| Pre-transplanting weeding | ||||
| Transplanting | ||||
| Fertiliser application | ||||
| Post-transplanting weeding | ||||
| Insecticide spraying | ||||
| Herbicide spraying | ||||
| Bird-scaring | ||||
| Harvesting | ||||
| Post-harvest handling | ||||
| Other (specify) | ||||