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This report was compiled by
Peter Macharia
, Kenya Soil Survey
.

last updated: 29 July 2004

 

News : Directory of Soil Institutions and Experts in Africa is available through [Link 2.2.1].[29/07/04]

icon overview   Overview (Geogrpahy, Socio-Economy, Climate)
icon land   Land resources
icon water   Water resources (AQUASTAT)
icon plant   Plant nutrient resources
icon hotspots   Hot spots
icon brightspots   Bright spots
icon challenges and view points   Challenges and viewpoints
icon references and links   References / Related internet links






1.   Country overview

1.1  Geography and administrative units

1.2  Socio-economic features

1.3  Climate

1. > top




1.1  Geography and administrative units


Kenya is located at the East Coast of Africa bordering Indian Ocean to the South East, Somalia to the East, Ethiopia to the North, Sudan to the North West, Tanzania to the South West and Uganda to the West with the Equator dividing the country into almost two equal halves (Figure 1). Kenya ranks 22nd in terms of size within the African continent with an area of 587,900 Km2 (58,900,000 ha), out of which 57,670,000 ha is land surface. 46,140,000 ha (83%) of the land surface is classified as Arid and Semi-Arid, with the remaining 11,530,000 ha (17%) being classified as medium to high potential. These classifications are based mainly on average annual rainfall and evapotranspiration, which are key determinants for agricultural production. The country lies between latitudes 50S and 50N and between longitudes 340E and 420E as shown in the following outline map.

[Map 1.1.1 (PDF): Outline Map]

Administratively, Kenya is divided into 8 provinces, which are further subdivided into 71 districts (Figure 2). The country is administered through a central Government although urban areas are administered through local Governments. Nairobi is the capital city of Kenya, while other major cities are Mombasa, Nakuru, Kisumu, Eldoret and Thika.

[Map 1.1.2 (PDF): Administrative Map]

1.1 > 1.


1.2  Socio-economic features


Population
Role of agriculture to Kenya's economy
Institutional arrangements of the agricultural sector
Infrastructure
Communications
Education
Health
Education
Major food and cash crops


Population

Kenya's population presently stands at 28,686,607 people with an annual growth rate of 2.9% ( GoK, 2000). Thirty years ago, the population was standing at 10,942,705 with annual growth rate of 3.4%. This shows that the annual growth rate has been declining since 1969 as shown in the following [Table 1.2.1].

[Table 1.2.1: Population distribution per province and the Intercensal Growth Rate (%)]

Out of the total population of 28,686,607, the females form the majority with 51.5%. The total population living in urban areas is 9,996,991 people of which the males are the majority with 51%. In the past years, the country has been experiencing a rural to urban immigration to seek for jobs and other economic activities. But due to scarcity of jobs and retrenchment of employees from both government and private sector, the trend presently is reversed towards urban to rural migration. Further, population statistics show that the age bracket below 15 years form about 44% of the population, while 16-64% age group forms 52% and the remaining 4% are people aged above 65 years.

The main economic sectors of the country since 1964 (after independence) are indicated on [Table 1.2.2].

[Table 1.2.2: Average growth rates of Real Gross Domestic Product (GDP), 1964-1995 (%)]

During the early years of independence, Kenya achieved commendable economic growth compared to other developing countries. Table 2 shows that for the period 1964 to 1973, Gross Domestic Product (GDP) grew on average by 6.6% per year. The rapid growth during the decade resulted mainly from successful rural development policies that led to increased agricultural output, import-substitution industrialization strategy supported by access to the East African Community markets and good macro-economic management. In the case of agriculture, the main source of growth was the expansion of land under cultivation and the introduction of more modern farming practices. As for the manufacturing sector, growth was largely due to the expanding domestic demand supported by rising agricultural incomes, the encouragement of investment through high levels of protection and an active Government role in industrial promotion and investment.

It can be seen from Table 2 that, during the period 1964 to 1973, the manufacturing sector registered an average growth rate of 9.1% and agriculture 4.6% per year, whereas during the periods 1980 to 1989 and 1990 to 1995, the annual average growth rates for manufacturing were 4.8% and 3.0% respectively and that for agriculture were 3.3% and 0.4% respectively. The two major sectors have recorded declining performance over the last three decades even though manufacturing appears to have been more resilient. Economists have said that during the year's 2000/01, the economy recorded a negative growth rate of -2.4%.

The service sector (including the public sector) contributes over half of Kenya's GDP and also provides over two-thirds of the total wage employment. Some of the potential comparative advantages that Kenya holds regionally and internationally stem from this sector. The tourism industry, for example, is the second highest single source of foreign exchange earnings after tea. Other services that have significant foreign earnings and employment include information technology, banking and finance and other professional services.


Role of agriculture to Kenya's economy

According to the National Development Plan (1997-2001), Kenya has since independence relied heavily on the agricultural sector as the base for economic growth, employment creation and foreign exchange generation. The contribution of the agricultural sector to real GDP growth has been higher vis-a-vis other sectors of the economy. During the period 1964-74, the sector contributed 36.6% of GDP, 1974-79, 33.2%, 1980-89, 29.8% and 1990-95, 26.2%.

Although agriculture's contribution to GDP growth has been declining over the past years, it remains one of the most important sectors driving economic growth and plays a central role in the employment generation. A large proportion of Kenya's labour force is based in rural areas. Available data show that small-scale agriculture absorbs the largest share of new additions to the labour force as well. Employment creation in the sector is expected to slow down in the future given the declining share of agriculture in GDP.

The total available area for sustainable agriculture is about 17%, which is carried out in the medium and high potential areas of the country. The rest of the country is classified as arid and semi-arid lands (ASAL). Since 1996, agricultural production has been declining except horticultural sector, which has expanded by 48.8%. For example, maize, which is the staple food for most of Kenyans, has fallen from 27.3 million bags in 1998 to 25.0 million bags in 1999. The country had to import 73.5 thousand tons. In the same period, wheat has fallen from 177.1 to 55.2 thousand tons. Coffee had an upward production with the sector registering 53.4 thousand tons in 1997/98 period but rose to 68.1 thousand tons of cherry during 1998/99 period.


Institutional arrangements of the agricultural sector

Increased investment in the sector and provision of strong linkages among the various actors is being realized through implementation of the Agricultural Sector Investment Program (ASIP). The program's main aim is to enhance sustainable development in the sector through a more integrated and holistic approach. The program tries to involve all the stakeholders in the agricultural process which requires institutionalizing linkages among them and systematic co-ordination with other sectors that must provide essential agricultural inputs and services, such as energy, access roads and water. The ASIP specifies the benefits for smallholder farmers in matters related to land tenure, infrastructure and credit.

Farmer associations and organizations are expected to play a greater role in facilitating dialogue among farmers, policy markers and other key stakeholders, such as processors and marketers. The ASIP has been primarily implemented through Ministry of Agriculture and Rural Development and has been specifically designed to both incorporate and maintain the participation of stakeholders.


Infrastructure

Kenya's transport system comprises five major modes namely: roads, railway, maritime, pipeline and air transport. The transport sector occupies a crucial position in the country's socio-economic development and integration. The road system facilitates transportation of both food and cash crops from the farms to the major urban areas and strengthens linkages with marketing and population centres.

The road network in Kenya currently accounts for over 80% of the country's total passenger and freight traffic. When the country attained independence in 1963, it had an estimated road network of 150,600 km, which consisted of 41,800 km of "classified" roads; only 1,811 km (about 11%) was bitumenized. Although the "classified" network which is under the responsibility of the Ministry of Public Works and Housing has been expanded to 63,663 km, only 8,804 km (or 14%) of it has been bitumenized. The "unclassified" roads, consisting of 80,000 km (or 53%) of the total network, are under the responsibility of Forest Department, Kenya Wildlife Service, various county councils and other local authorities. Municipal authorities and city of Nairobi account for about 7,000 km of roads.

Railway transport provided by the Kenya Railways Corporation (KR) is the second most important mode after road transport. Currently, freight haulage accounts for more than 80% of KR's total annual revenue earnings while passenger transport accounts for only 10% of its revenue. Other services such as catering, marine transport on Lake Victoria, transportation of livestock and coaching services contribute to the other 10% of revenue.

Marine transport in Kenya consists of port facilities in Mombasa, shipping and inland water transport. Inland container depots at Nairobi, Kisumu and Eldoret, which are also managed by the Kenya Ports Authority (KPA), fall under this mode of transport.

Air transport remains the key sub-sector for the development of tourism, the transportation of high value exports and perishable goods (especially horticulture which is a major source of foreign exchange) and for promoting regional integration following the privatization of Kenya Airways (the national carrier), the Government's attention in this sector has been focussed on the improvement of efficiency of airport facilities, particularly in the areas of maintenance and equipment, by improving the quality of airport service and by strengthening the relevant institutions. In order to increase its managerial autonomy, the Government exempted the Kenya Airports Authority (KAA), among other parastatals, from the provisions of the State Corporations Act in March 1996.

In terms of Pipeline transport, the extension of the Mombasa-Nairobi pipeline to Kisumu and Eldoret was completed and commissioned in 1995. Arrangements are already underway to extend the pipeline to Uganda and other neighbouring countries.


Communications

In the telecommunications sub-sector, the number of telephone exchange connections has been rising steadily from 200,000 in 1991 to 250,000 in 1995 reflecting an annual growth of 6.3% with an exchange fill of 66.2% and a telephone density (i.e. the numbers of exchange connections per 1,000 population) of 9.4 lines per 1,000 people. The total telephone exchange capacity is expected to increase from 376,948 lines in 1995 to 673,412 lines in the year 2001, an average annual growth rate of 10%. The total telephone exchange connections will also increase at 13.4% p.a. from 249,604 lines to 505,966 lines during the plan period. This is expected to raise the telephone density from 9.4 to 15.2 lines per 1,000 people. Automation of telephone services has been proceeding rapidly from 168,621 automatic exchange connections in 1990 to 242,638 connections in 1995.

In addition, two companies are presently providing mobile telephone services. These are Safaricom and Kencell. The liberalization of these services has brought an upshot to the number of people using these services, which for a long time had been monopolized by the Kenya Posts and Telecommunications Corporation (KPTC).


Education

One of the Government's guiding philosophies for education is the concern that every Kenyan has the inalienable right no matter his or her socio-economic status, to basic education. Since independence, the expansion of education facilities has been the single most important challenge on the human resource development front. The Government has met this challenge head on and achieved some impressive results in enrollment ratios as indicated in [Table 1.2.3].

[Table 1.2.3: Trends in educational enrollment, 1963-1995 (000's)]

[Table 1.2.3] indicates that there has been rapid growth in enrollment at all levels of education with the rate of enrollment growth raising the higher level of education. The gender bias of education is also close to being eliminated at primary level but is still significant at all other education levels, with the exception of teacher training. During the 1997-2001 period, the greatest increase in demand for education will emanate from the tertiary sub-sector which is projected to increase by 13.1% as can be seen from [Table 1.2.4].

[Table 1.2.4: Projected demand for education 1997-2001 (millions)]

The second increase in demand will emanate from primary and secondary education, which will increase by 7.0 and 5.9% respectively. The tertiary schools include teacher education, polytechnics, technical institutes, institutes of technology and the universities. Enrollment at the tertiary level in Kenya is currently around 4% of the relevant population, with half of that being at university level.


Health

Good health is both a basic right and a pre-requisite for rapid socio-economic development and a healthy population is a basic requirement for successful industrialization. The Government recognizes this fact and has invested heavily both in the expansion of health personnel and in health infrastructure. It is mainly as a consequence of these efforts that life expectancy rose from 40 to 58 years between 1960 and 1994, infant mortality declined from 126 per 1,000 to 60 per 1,000 between 1962 and 1994. A major drawback in recent years has been an outbound movement of doctors to other countries especially South African countries and USA where they receive better pay and better working conditions.

Preventable, vector-borne diseases are generally the main cause of morbidity and mortality nationwide. Malaria and respiratory diseases account for almost 50% of all reported diagnosis in Government health facilities, and intestinal parasitic infections and diarrhea increase this number to almost 60% of all reported cases.

The single most important health challenge that Kenya has faced in its post independence history is the HIV/AIDS pandemic. It is the only known health problem that has the potential to reverse the significant gains made in life expectancy and infant mortality. Health experts presently estimate that about 500 people die daily and that over 2 million people are infected by the HIV/AIDS. The disease has already been declared a national disaster in the country. By 1999, the health care delivery system in the country composed of a total of 4,235 health institutions rising from 3,500 in 1995. The total number of doctors in 1999 was 5,145 (a ratio of 15.3 per 100,000 people and 27,073 nurses).


Major food and cash crops

Maize is Kenya's most important food crop. The area under maize cultivation has stabilized at around 1.4 million hectares with limited potential for further expansion. Due to changes in weather conditions, maize production fluctuates sometimes leading to serious shortfalls. The country has the potential to produce enough wheat for local consumption, which is estimated at 6 million bags annually. However, due to various technological and social constraints, the country produces about 3 million bags annually. Major constraints contributing to the low productivity of wheat farming in the country include: technological packages that favour large-scale farmers; poor credit facilities to smallholder farmers; limited land to grow crops and poor supply of inputs. Other important food crops and their trends in production are beans, potatoes, sorghum and millet. Their estimated production between 1993 and 1996 is as shown in [Table 1.2.5]. [Map 1.2.1] shows some of the major cash crops.

[Map 1.2.1: Major cash crops]

[Table 1.2.5: Estimated production of selected food crops between 1993 and 1996 (In million bags)]

The average maize yield is about 5 tons/ha but potential exists for increasing the yield to about 10 tons/ha through increased use of improved seeds, fertilizers and good crop husbandry. The export of industrial (cash) crops has traditionally provided the bulk of Kenya's foreign exchange earnings. Coffee, tea and sugar have also played a key role in creating agro-based industrial employment opportunities. The following [Table 1.2.6], [Table 1.2.7] and [Table 1.2.8] show the production and trend of coffee, tea and sugar between 1992 and 1995.

[Table 1.2.6: Coffee production by area and average yield by grower type, 1992/93 - 1994/95]

[Table 1.2.7: Tea production by area and average yield by grower type, 1992/93 - 1994/95]

[Table 1.2.8: Sugar production, imports and consumption, 1992 - 1995 (tonnes)]

Tea is presently Kenya's leading export earner accounting for nearly 20% of total export earnings. There are however, differentials in yield and quality between estates and smallholder, and also among small holders to the east and west of the Rift Valley. The yield of smallholder producers is currently about 58% of that achieved by estate producers. Increasing the use of fertilizers and adopting intensive techniques of harvesting can greatly enhance smallholder yields.

Self-sufficiency in sugar has remained elusive over the years. The consumption of sugar continues to increase while local sugar production has been decreasing, leading to higher levels of imports. Given the current rate of population growth, it is projected that the demand for sugar will reach 800,000 tonnes by the end of year 2001.

Horticultural production has continued to perform well and is dominated by small-scale growers who number about 2 million and constitute about 80% of all producers. The principal horticultural exports are cut flowers, French beans, garden peas, mangoes, avocadoes, processed and fresh pineapples and Asian vegetables. Besides generating employment, horticulture also provides important nutrients for the rural population. Constraints affecting the horticultural sector are poor infrastructure, distance from international airports, inadequate cooling facilities, fluctuations in electricity supply and international standards such as ISO-14000 series, which could restrict access to lucrative markets.

Other important industrial crops grown in the country are oil crops, pyrethrum, cashew nuts and bixa.


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1.3  Climate


General climate description
Length of growing period
Relative humidity
Temperatures


General climate description

In Kenya, 83% of the country is classified as arid and semi-arid (ASAL) and falls under agro-climatic zones IV-VII. The remaining 17% is classified as medium to high potential areas and fall under agro-climatic zones I-III. As can be seen from [Table 1.3.1] and [Map 1.3.1], sustainable agricultural production under rainfed conditions is only possible in zones I-III.

[Table 1.3.1: Moisture availability zones with an indication of rainfall and vegetation]

[Map 1.3.1: Agro-climatic zones map of Kenya]

The country receives a bimodal type of rainfall where the "long rains" falls between March and May while the "short rains" fall between October and December. The intensity and spread of the rainfall in each region determines the effectiveness of the rainfall.

The average annual rainfall ranges from 250 to 2500 mm, the average potential evaporation ranges from less than 1200 mm to 2500 mm, and the average annual temperature ranges from less than 100 to 300C. There are many different rainfall distribution types (Sombroek et al., 1980).

A relatively wet belt extends along the Indian Ocean Coast and another wet area covers western Kenya just east of Lake Victoria. All the mountain ranges have high rainfall while dry tongues are found in the valleys and basins. The annual rainfall generally follows a strong seasonal pattern. The seasonal variations are strongest in the dry low lands of the north and east, weakest in the humid highlands of the Central and Rift Valley areas.

All places experience a more or less strong seasonal variation. The seasons differ somewhat throughout the country but can generally be classified under three main types:

1) Indian Ocean Coastal Area:
The year starts dry and remains so until March when rainfall gradually increases. A fairly rapid increase occurs through April and builds up to a rainfall maximum in May. Then rainfall decreases steadily but significant amounts are still recorded in October and November. During December, a rapid decrease is experienced that leads to the rainfall minimum in January and February.

2) Eastern, North-Eastern, South-Eastern and Central areas:
There occurs two rainy seasons, March-May and October-December, separated by a minimum (June-September), which is most distinct in the lower areas of eastern Kenya. April is generally the rainiest month but there have been years when exceptionally heavy rains gave record totals in October and November (esp. during the El Nino rains of 1997/98). The second minimum, January-February, is again most pronounced in the low eastern regions.

3) Western Rift Valley, Western and Lake Victoria areas:
There is no really dry season. Rainfall is high during March-September and low during January-February. Rainfall in central and western areas is mostly convective in the form of thunderstorms and showers from cumulus-form clouds during afternoons. In eastern areas, especially along eastward-facing slopes, prolonged rain and drizzle fall from extensive stratus-form cloud sheets, frequently during the night. The coastal belt experiences most of its rainfall during the morning from trade wind cumulus clouds but occasionally also prolonged rain from stratified cloud sheets.


Length of growing period

The duration of the growing season depends partly on climatic factors (mainly rainfall, evaporation and temperature), partly on soil factors (mainly the amount of moisture that infiltrates and is retained in the soil) and on crop factors (the most important being the rooting and intrinsic phenology i.e. maturing characteristics) (Sombroek et al., 1980). An example of the variation in the duration of the growing period during the long and short rains is given in the following [Table 1.3.2].

[Table 1.3.2: Percentage of rainy seasons in Embu with a growing period less than 50, 70, 90, 120, 150 and 180 days long (from 40 years data)]

Using average data, the duration of the growing period was calculated to be 130 and 102 days for the long and short rains respectively. Such data are very useful for assessing which crop or crop varieties is suitable to be grown in the long and short rains with a certain degree of risk.


Relative humidity

It is the measure of the amount of water vapour in the air as compared with the maximum amount that can be contained at a certain temperature. It is always a maximum at the temperature minimum (early morning) and a minimum at the temperature maximum (afternoon). In areas with vegetation, the maximum normally exceeds 90%, in arid areas it reaches between 60% and 70%. The minimum varies significantly with elevation and time of the year: typical values being 70% at the coast at all seasons, 60% for the highlands in the rainy season, and 40% for highlands in the dry season.

Sunshine is generally high throughout the country with one exception: Eastern-central and southern areas experience prolonged cloudiness during the period June-September.


Temperatures

Mean temperatures in Kenya are closely related to ground elevation. The highest temperatures are recorded in the arid regions of the North-Eastern province along the Somalia Coast and to the west of lake Turkana where the night minimum maybe as high as 290C during the rainy seasons. Coldest are, naturally, the tops of the mountains where night frost occurs above 10,000 feet and permanent snow or ice cover above 16,000 feet (Mt. Kenya). Annual temperature variations are generally small (less than 50C) throughout the country. The hourly temperatures however, differ considerably between day and night and temperature ranges between maximum and minimum vary from 60C at the coast to 160C in the highlands.

[Table 1.3.3: Temperature zones with an indication of mean maximum, mean minimum and absolute minimum temperatures, night frost and altitude]


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2.   Land resources

2.1  Physiography

2.2  Soils

2.3  Agroecological systems

2.4  Wetlands, mangroves and inland valley bottoms

2.5  Inundation Land Types

2.6  Natural hazards

2.7  Land cover

2.8  Land use

2.9  Land use change

2.10  Land Productivity

2.11  Environmental Impact of land uses

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2.1  Physiography


Physiographic units

Landforms refer to elements in the landscape characterized by a distinctive surface expression, internal structure or both and sufficiently conspicuous to be included in a physiographic description. They may be defined as a particular association that can be seen at a single view. The major landforms recognized in Kenya are ten along with eight miscellaneous land types. In describing the landforms, the following characteristics have been used:

a) Relief intensity- vertical difference between the higher and lower parts of the landscape
b) Slope (class) - The dominant overall slope class of a landform

As a consequence, the following landforms are recognized in Kenya:

  1. Mountains and major scarps
  2. Volcanic foot ridges
  3. Footslopes and pediments
  4. Piedmont plains
  5. Pediplains
  6. Plateaus and high level structural plains
  7. Uplands and dissected peneplains
  8. Plains
  9. Floodplains
  10. Bottomlands

Mountains and Major Scarps

A mountain is a natural elevation of the earth surface rising more or less abruptly from the surrounding levels, and attaining an altitude which is relatively to adjacent elevation is impressive or with a notable relief intensity >300 m.

Volcanic Footridges

The term "volcanic footridges" was coined to describe a landform that consists of broad parallel, rather convex interfluves alternating with deeply incised Valleys, often with convex slopes and with a narrow valley bottom.

Footslopes and Piedmonts

A footslope is a general term for a hillside surface whose upper part is the wash slope and that includes the slopes of diminishing gradient.
Piedmont is a broad, flat gently sloping rock floored erosion surface or a plain of low relief.

Piedmont plains

A Piedmont plain is a plain situated at the foot of mountains or hills. The equivalent of the piedmont alluvium or piedmont plain in semi-arid lands is Bajada.
Generally, these plains are continuous, gently sloping, formed by the lateral coalescence of a series of separate but confluent alluvial fans.

Plateaus and High Level Structural Plains

A Plateau is an elevated track of comparatively flat or level ground, commonly bound on at least one side by an abrupt slope (scarp).
High Level Structural Plains are included in this physiographic unit. They are relatively flat areas underlain by horizontal or slightly inclined strata of unequal resistance to weathering.

Uplands and Dissected Peneplains

These landforms concern surfaces of erosion and former accumulation which are undergoing processes of land degradation of slight to moderate intensity.
A Plain is an extensive region of comparatively flat, smooth & level to gently undulating land having no or few prominent surface irregularities.

Floodplains

These are strips of relatively smooth and adjacent to a river channel, formed or in process of being formed by the present river and covered with river water when flooded.

Bottomlands

These are track of lands of depressed topography without visible drainage outlet.


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2.2  Soils


Physiographic units

Kenya has a wide range of soils as shown in Map 2.2.1 but the major ones are 19 namely:

Acrisols and Lixisols - very acid soils and mostly found in highly rainfall areas
Cambisols - young and little weathered soils
Chernozems - dark coloured soils rich in organic matter
Ferralsols - highly weathered soils- mostly found in arid and semi-arid areas
Gleysols - Poorly drained soils and mostly found in bottomlands
Phaeozems - Dark coloured soils rich in organic matter, mostly found in high rainfall: areas eg. Central Kenya highlands, Kisii and Western Kenya highlands
Leptosols - Soils with hard rock at very shallow depth
Fluvisols - Alluvial soils, found mostly along the banks of the major rivers where there is frequent flooding.
Luvisols and Alisols - Soils with illuvial accumulation of clay, widely found in many areas of the country.
Nitisols - Deep, red friable soils, mostly found in high rainfall areas especially the highlands.
Arenosols - Sandy soils, found mostly along the coastline and Coastal plains.
Regosols - Weakly developed soils of loose material.
Solonetz - Alkali soils, found mostly in arid and semi-arid areas.
Andosols - Volcanic soils, found mostly where volcanic had occurred.
Vertisols - dark coloured, strongly cracking soils, found mostly in rice growing areas - Mwea in Krinyaga District and Kano plains in Nyanza Province.
Planosols - Soils with eluviated horizon and mostly found at the footslopes of the mountains and the ridges.
Histosols - poorly drained soils with thick topsoil that contains fresh or partly decomposed organic matter. (Bog and marsh soils).
Gleyzems - Soils rich in organic matter and having grey colour.
Solonchaks - Strongly saline soils with so much soluble salt that is harmful to the crops.

[Map 2.2.1: Soil map]

[Link 2.2.1: Directory of Soil Institutions and Experts in Africa]

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2.3  Agroecological systems


An Agro-Ecological Zone (AEZ) is a zone, which is defined by its relevant agro-climatic factors (in the tropics mostly moisture supply) and differentiated by soil pattern and having a specific range of potentials and constraints for land use. The aim being to provide natural land use potential. Zone groups are defined according to maximum temperature limits within which main crops in Kenya can flourish; eg cashew nuts and coconuts for the lowlands, sugar-cane and cotton for the lower midlands, tea for the lower highlands, pyrethrum for the upper highlands and coffee for the upper midlands. The country lies under various AEZ ranging from Tropical Alpine (at the mountains and hills (TAs) to coastal lowlands (CLs).


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2.4  Wetlands, mangroves and inland valley bottoms


The Ramsar definition of wetlands covers a range of marine, coastal and inland habitats, which in Kenya includes deltas, estuaries, mangroves and marine mudflats as well as marshes, bogs, floodplains, shallow lakes and the edges of deep lakes and rivers. The marine wetlands can include sea grass beds and coral reefs, provided that these are not deeper than six meters, a depth that was chosen to make sure that all wetlands contain vegetation influenced by light (IUCN, 1992). Kenya's most famous wetlands are the shallow lakes of the Great Rift Valley, the edges of Lake Victoria and the mangrove forests of the coast.

Most of the wetlands in Kenya are found along the major rivers of Kenya and especially at the outlet mouths while mangroves are found along the coastline of Indian Ocean, where environmental conditions suit them. Coral reefs, wetlands, mangroves and lowland forests are important ecosystems of the Kenyan Coast. The mangrove forests provide nurseries for fish and crustaceans, and protect the coastline from erosion. The lowland forests are characterized by great biodiversity. However, these ecosystems are threatened in many ways. Coral reefs are deteriorating, mangrove forests are overexploited, forest reserves are threatened, unrestricted surface mining leads to erosion and groundwater is becoming increasingly saline and contaminated. The damage occurs to some extent from naturally occurring geophysical processes, but more from the increased subsistence needs of the population and from growing commercial exploitation.

Apart from the above pockets of wetlands, Kenya has national parks and reserves, which are very important as wetlands. [Table 2.4.1] shows some of the wetlands in Kenya.

[Table 2.4.1: Wetlands within conservation areas in Kenya]

Kenya's wetlands, covering 14,000 Km2 are a source of great social-cultural and economic potential. Many of Kenya's rural communities draw food, medicinal products, firewood, materials for building and handicraft from wetlands. However, these ecosystems are today facing a serious threat to their confined existence from encroaching human development activities, especially agricultural operations. The physical wetland products may be indirectly or directly consumed, but social-cultural benefits cannot be readily quantified. Different people have historical and current associations with wetlands. The spatial distribution of wetlands in Kenya is uneven and several communities with different social-cultural backgrounds utilize them.

There are many hundreds of small wetlands (such as swamps, small lakes, soaks and riverine floodplains) that are distributed throughout the wetter areas of the country. Generally, these are found in the higher rainfall areas of the west and central parts of Kenya where water is relatively abundant. But there are some very important small wetlands that occur in the drier parts as a result of the occasional flows of ephemeral rivers or as the output of springs from distant water sources. It is these wetlands in drylands that are so important to the people, livestock and wildlife as refuges in times of drought.


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2.5  Inundation Land Types


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2.6  Natural hazards


The severe natural hazards in Kenya include bush fires especially on the forested areas during the drought period, flooding especially in Kano plains in Nyanza low plateau and along the Nzoia riverbanks. The frequent droughts affect the whole country usually in a 10-year circle. Other natural hazards are the pests and diseases, which affects the crops and livestock. The country also experiences hailstorms, which damages food crops, especially in western and Central regions of Kenya. The floods that occur in Western and Nyanza regions also damage food crops in a great scale but the government is building dykes to prevent further damage from the flooding rivers.


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2.7  Land cover


Forests occupy about 3% of the high and medium agricultural potential land (Agro-climatic Zones I-III) with the rest of the land being used for cash or food crop production. The cash crops include tea, coffee and others. Food crops are invariably maize, legumes and others. Coffee, rice and various horticultural crops are produced under irrigation mainly in the agro-climatic zone III. The drier areas (Agro-climatic zones IV-VII) are mainly bushlands and scrublands. In the wetter areas food crops (maize, beans, pigeon pees, etc) are produced. The drier areas are predominantly used for livestock grazing.


Trends in Land Cover

Kenya has a total area of 587,900 square kilometers, 17% of which is of high and medium potential while 83% is arid and semi-arid. Currently, Kenya has a population of over 28 million people, majority of who derive their livelihood from land-based resources. About 80% of the population lives in the first land category where also natural forests, which form the water catchments area, are also located. This means that there is a lot of pressure on land, which results to conflicts in land use. The bulk of the land, which falls within the arid and semi-arid areas, supports only 20% of the population but with proper land use management, the carrying capacity can be enhanced without deterioration of the fragile ecosystem.

Kenya is essentially an agricultural country with agriculture contributing 30% of the GDP. However, the land under agriculture has been diminishing due to competition from other uses e.g. rapid urbanization and sub-division of land to un-economical sizes among others. Due to high population growth and changes in the social modes of production, the country is experiencing severe environmental problems associated mainly with forest depletion, destruction of water catchment areas, soil degradation and destruction of wildlife habitats. The tourism sector is largely dependent upon wildlife resources and the natural environment, which must be conserved for posterity.

The current trends in urbanization growth have resulted into socio-economic problems associated with their rapid growth. During the 1979 population census, about 2 million people lived in the urban areas, which rose to 3.5 million and 6 million in 1989 and 1999 respectively. This trend is expected to continue with several attendant problems and land use conflicts such as encroachment on agricultural land, forestry and riparian reserves among others.


2.7 > 2.


2.8  Land use


The high and medium potential land is used mainly for intensive crop and dairy production while most of the arid and semi-arid lands (ASAL) are largely used for extensive livestock production systems such as ranching and pastoralism as well as being a habitat for wildlife in the national parks and game reserves. [Map 2.8.1] shows some of the land uses.

[Map 2.8.1: Land use]

[Map 2.8.2: Land classification map]


Land Use Classes in Kenya

There are 9 land use classes in Kenya namely:

Class 1
Settled and non-agricultural lands, which are divided into commercial, residential and industrial sub-types. The big commercial centers include Nairobi, Mombasa, Kisumu, Nakuru, Kitale, Thika and Eldoret.

Class 2
This category refers to horticulture and market gardening composed mainly of vegetables, carrots, tomatoes, fruits etc. The products of these areas are consumed in local urban areas. Medium to large-scale horticulture growing is mainly for the export market.

Class 3
Areas of perennial cropland (mainly tree crops and other perennials) eg Tea, Coffee, Sugarcane, Bananas etc.

Class 4
This class includes arable cropping of beans, maize, wheat, rice etc. In many cases this is in medium to high rainfall areas

Class 5
Mainly includes improved grazing areas (pastures and ranches), where paddocking and growing of fodder are practiced.

Class 6
This class is un-improved grazing land (rangeland). It is found in semi-arid and arid areas of the country. This category also includes the moorland on top of mountains. Various forms of pastoralism are the main land use, but also various wildlife animals are found.

Class 7
This includes the woodlands and forest types. This ranges from dense forests to mixture of bushes and woodlands including planted forests and riverine woodlands. This land use class is mainly found in areas receiving high rainfall (>1000 mm).

Class 8
This category includes water bodies such as ponds, lakes, marshes and swamps. Fishing is the most important land use except Lake Magadi where soda ash mining is the main activity.

Class 9
This includes mainly the barren lands, which are agriculturally unproductive. Mostly found in northern Kenya (Chalbi Desert) plus some other smaller areas around Tsavo National Park and Oloitoktok areas (near Kilaguni Lodge) in Kajiado District.


2.8 > 2.


2.9  Land use change


Due to population pressure in the high potential agricultural areas (17% of the country), there is a tendency of people migrating to the ASAL areas to own land for settlement and for agricultural purposes. As a result, land degradation is accelerated in such areas due to clearing of bushes and felling of trees leading to depletion of soil fertility. Pastoralism is mainly practiced in these ASAL areas, but after the immigration of people from high potential areas, the land use is changing to agro-pastoralism, which has been the major cause of land degradation. Secondly, urban settlements are mushrooming in the high potential areas and due to migration of the people from rural areas to urban towns, there is a likelihood of expansion of these towns towards the agricultural areas making the land used for agricultural purposes to continue diminishing.


2.9 > 2.


2.10  Land Productivity


Land productivity in general has been on a decline as seen from [Table 2.10.1], which gives an indication of centrally marketed crops by the National Cereals and Produce Board (NCPB).

[Table 2.10.1: Sale of some major crops to Marketing Boards, 1996-2000]

As shown from [Table 2.10.1], maize production declined from 223.5 thousand tonnes in 1999 to 201.2 thousand tonnes. Consequently, 409.4 thousand tonnes of maize valued at Ksh. 4,700 million were imported to reduce the deficit. The production deficit was largely due to inadequate rainfall in the maize growing regions during the crop season coupled with low supply of quality seeds, high cost of farm inputs, and infestation of maize farms by armyworms and poor crop husbandry.

Production of wheat has been low for the last two years, 1999 and 2000 registering 55.4 thousand tonnes and 73.8 thousand tonnes respectively compared with a record 177.1 thousand tonnes produced in 1998. An additional 636.0 thousand tonnes of wheat valued at 7.0 billion was imported in 2000 to meet the production deficit. The low production could be attributed to drought, low wheat prices offered by millers, invasion of wheat farms by wildlife seeking pasture.

In 1999/2000 crop year, coffee production increased by 47.9% from 68.1 thousand tonnes in 1998/99 crop year to 100.7 thousand tonnes. This was in response to high prices during the previous coffee seasons coupled with improved crop husbandry. The area under coffee remained at 42 and 128 thousand hectares for estates and co-operatives respectively. Poor infrastructure and lack of access to credit has in some cases resulted in substitution of coffee with other crops such as tea and horticultural crops.

Tea production declined by 5.0% from 248.7 thousand tonnes in 1999 to 263.3 thousand tonnes in 2000. The decline in tea production in the last two years was attributed to the dry weather. In addition, frost in some tea growing areas adversely affected tea production in the early part of the year 2000. Total area planted with tea, however increased by 1.5% from 124.2 thousand hectares in 1999 to 126.1 thousand hectares in 2000. Consequently, the average yield increased from 1,729.15 Kg/ha in 1999 to 1,775.17 Kg/ha in 2000 for smallholders and from 3,278.77 Kg/ha to 3,477.27 Kg/ha for estates. Improved crop husbandry, roads and proper and timely application of inputs has resulted in the increased productivity.

Intake of seed cotton by ginneries increased from 200 tonnes in 1999 to 508 tonnes in 2000. However, the price of a 100 Kg bale of cotton declined slightly from Ksh. 2,000 in 1999 to Ksh. 1,910 in 2000. Second-hand imported clothes and managerial problems in the cotton sub-sector explain the generally low production level.

Sugar-cane production declined by 10.7% from 4.4 million tonnes in 1999 to 3.9 million tonnes in 2000. The average yield reduced to 60.5 tonnes/ha in 2000 from 78.4 tonnes/ha in 1999. Sugar-production fell by 14.6% to stand at 402.0 thousand tonnes in 2000. Sugar imports rose by 104.5% from 57.7 thousand tonnes to 118.0 thousand tonnes as a result of the supply/demand gap in 2000. The decline in sugar production was largely attributed to the long spell of dry weather; management problems in sugar milling; and the rejection by millers of unscheduled cane supply occasioned by fires.

As shown in [Table 2.10.2], the volume of horticultural exports rose marginally by 0.2 thousand tonnes from 99.0 thousand tonnes in 1999 to 99.2 thousand tonnes in 2000.

[Table 2.10.2: Exports of fresh horticultural produce 1996-2000]

Sisal production declined by 2.3% from 21,923 tonnes in 1999 to 21,429 tonnes in 2000. However, sisal prices dropped by 5.3% from Ksh. 39,899 per tonne in 1999 to Ksh. 37,794 per tonne in 2000.

As concerns livestock and livestock products, the total recorded milk production declined by 23.9% from 180 million litres in 1999 to 137 million litres in 2000. Unfavourable weather and delay in payment of farmers contributed to the decrease in production. Processed whole milk and cream increased by 9.1% from 55 million litres to 60 million litres. The total number of livestock slaughtered went up for all categories in 2000. Drought in many parts of the country resulted in shortage of water and pasture. This led to increased livestock deaths and livestock slaughtered as farmers disposed off a large number of their livestock. The number of cattle and calves slaughtered went up by 5.7%, sheep and goats increased by 5.0% while that of pigs increased by 19.6%.


2.10 > 2.


2.11  Environmental Impact of land uses


Environmental impact of land uses

Declining soil fertility is a serious concern in Kenya. This is because for most cereal and legume crops grown in the country, nutrients removed in the harvested parts are not returned to the fields. The harvested parts are exported off-farm for sale or transferred to a different part of the farm e.g. as in animal feed or in trash lines. Some farmers use some plant parts for fuel wood and as building materials. Manure produced on the farm maybe returned to the field where animal feed was gathered from, to a different part of the farm or even sold off farm.

Many smallholder farmers in the country have not yet realized the value of using green manure and compost to maintain and improve soil fertility (KARI, 2001). The consequences of these actions for smallholder farms, particularly in the last two decades, have been a progressive decline in yields and diminishing soil fertility. This has occurred in spite of the successive introduction of new crop varieties and associated fertilizer and pesticide packages. Several reasons have been advanced to explain the decline of food production in Kenya. They are natural disasters (flood, drought), a high incidence of pests and diseases and degradation of soil resource base characterized by a decline in soil organic matter and nutrient availability.

Eutrophication of water bodies has been serious especially in Lakes Victoria and Naivasha. For example, the catchments of Lake Victoria have continued to experience serious environmental degradation, inappropriate land use methods which have led to deforestation, soil infertility, bio-diversity loss, floods and siltation in the lower areas of the basin. In this regard, the Lake Basin Development Authority (LBDA) has carried out an integrated feasibility study on River Nyando basin. Persistent issues addressed by the authority include amounts of semi-treated industrial and domestic discharges on River Nyando, high soil erosion and Biological Oxygen Demand (BOD) levels.

A number of studies have revealed wide variations in BOD levels ranging from 150 mg/l for East African Sugar Industries to 2,800 mg/l for Agro-Chemical Food Company. Most of the municipalities do not have waste treatment works resulting in very high BOD levels of 390 mg/l for Kakamega and 303 mg/l for Kisumu. Poor management and insufficient maintenance of the treatment plants are some of the reasons given for the municipality's environmental deterioration.


2.11 > 2.

3.   Water Resources (AQUASTAT)

3.1  Hydrography

3.2  Irrigation and drainage

3. > top



Country information on water resources is available at AQUASTAT - Kenya.

3.1  Hydrography


Drainage system
Hydro-geological
Surface water abstraction
Dams


Drainage system

The drainage system in Kenya is determined by the Great Rift Valley, which runs in an approximately north-south direction, and from its flanks, water flows westwards to Lake Victoria and eastwards to Indian Ocean. Kenya's drainage system is subdivided into five drainage areas (basins) consisting of 192 subdivisions (Cege, 1968). The five drainage areas are as follows:

1)  Lake Victoria basin (46,229 km2) comprises the whole of the area west of the Rift Valley that drains into Lake Victoria.

2)  The Rift Valley area (130,452 Km2) is an area of internal drainage discharging into Lake Turkana in the north and Lake Natron to the south.

3)  The Athi/Sabaki River area (66,837 Km2) comprises the southern part of the country east of the Rift Valley. It drains the southern slopes of the Aberdare ranges and flanks of the Rift Valley south of the Athi River.

4)  The Tana River area (126,026 km2) drains the eastern slopes of the Aberdare ranges, the southern slopes of Mt. Kenya and the Nyambene ranges and discharges into the Indian Ocean. The Tana is largest river in Kenya.

5)  The Ewaso Nyiro North River area (210,226 Km2) comprises the northern part of Kenya and drains the northern slopes of the Aberdare ranges and Mt. Kenya, into the Indian Ocean.


Hydro-geological

The geological units can generally distinguish the hydro-geological regions or units in Kenya as rock types are the most important determinants of ground water. Three main hydro-geological regions are recognized as follows:- Pre-Cambrian (Basement) metamorphic rock and intrusive region and sedimentary rock regions.

  1. Ground water in the volcanic regions occurs at varying depths and several quifers may exist on top of each other. The aquifers in these areas are confined and the depths to the aquifers and piezometric levels within them vary widely. The average yields are about 7.5 m3/hr. The depth to the aquifers on average is 94 m.
  2. The aquifers in the Basement area are mainly semi-confined. Yield depth to aquifers and static water levels vary within the rocks. Sample statistics for the country give an average yield of 4.5 m3/hr, an average depth to main aquifer of 55 m.
  3. The sedimentary rocks cover approximately 55% of the surface area of Kenya. The yields in these aquifers range from 8.0 m3/hr to 3 m3/hr. Depth of aquifers vary widely.

Rivers in Kenya are classified into two main types. Perennial (mostly found in the Central, Western and Coastal areas of the country and seasonal (commonly known as Lagas) and mainly found in semi-arid and arid areas. Floods occurrence in Kenya occurs intermittently. An attempt has been made to draw up a chronology of flood events from reports, survey interviews and field reconnaissance as well as interpretations of water level records at gauging stations. According to this information the 1961 floods were the severest in the last 33 years. Other severe floods occurred in 1963/64, 1968, 1977/78, 1982, 1985, 1988, 1990, 1992, 1993, 1994 and 1997. Most of these floods usually affect mainly Lake Victoria and Coastal area basins. These floods inundated the Kano plains, Yala swamps and other low-lying areas around Lake Victoria. They also hit the lower Tana reaches.


Surface water abstraction

According to surface water abstraction permits, not only water supply schemes such as the department of water, municipalities and self help schemes, but also a large number of farms, industrial firms, institutions and others take surface water for domestic use. The Department of Water has maintained a database for water abstraction permits for many years. Though there seems to be several problems, the present water permit database is used for estimation of the amount water abstracted from surface water sources for domestic, industrial uses and other uses.


Dams

According to surface water abstraction permits, not only water supply schemes such as the department of water, municipalities and self help schemes, but also a large number of farms, industrial firms, institutions and others take surface water for domestic use. The Department of Water has maintained a database for water abstraction permits for many years. Though there seems to be several problems, the present water permit database is used for estimation of the amount water abstracted from surface water sources for domestic, industrial uses and other uses.

The number of existing and under construction large-scale dams are 36 in all the river basins in the country. However, the exact number of the existing and under construction small scale dams is hardly known but a figure of 799 can be read from data of the water permit prepared by the department of Water in the period between 1938 and 1989 as the number of existing dams in the country. Not much is done to re-use the wastewater in the country. Surface water occupies about 16,860,000 ha, which includes 1,120,000 ha inland water and 1,430,000 ha of Indian Ocean territorial waters. A further 14,310,000 ha includes the exclusive Economic Zone within the Indian Ocean.

By 1997, the total number of water supplies maintained by the Government of Kenya was 401 (107 in urban areas and 294 in rural areas). In ASAL areas, inadequacy and unreliability of water supplies poses the most serious development constraint towards agricultural, livestock and even human resource development activities. Where available and inadequate supplies, either through surface and/or ground water resources, they have been developed and in the process become focal points for environmental degradation. This is attributable to overgrazing, deforestation and general destruction of the environment arising from high concentrations of human and livestock populations. The major uses of boreholes are public water supply, agricultural, domestic and industrial uses as shown in [Table 3.1.1].

[Table 3.1.1: Number of boreholes and their uses]

Groundwater in the dry areas has been found to have high contents of carbonates and bicarbonates and therefore of low quality for irrigation. [Table 3.1.2] shows the major river catchments in the country and the ecological development potential.

[Table 3.1.2: Major catchments and river basins in Kenya]

Rock types remarkably affect aquifer characteristics. The country is considered to consist of three major rock types, i.e. volcanic, basement and sediment rocks. The number of boreholes in each rock type is shown in the following [Table 3.1.3].

[Table 3.1.3: Number of boreholes and the rock types from where they are sinked from]

Total depth of boreholes in the volcanics is deepest, average value being 127 m. Boreholes in basement rocks and sediments have mean depth of 84 and 82 m respectively.


3.1 > 3.


3.2  Irrigation and drainage


Irrigatioin
Drainage


Irrigation

The irrigation potential in Kenya was estimated at 200,000 ha in 1974, 250,000 ha in 1977 and 540,000 in 1979 (Toksoz, 1981). The potential in Kenya for land reclamation by drainage and flood protection is estimated to be about 600,000 ha located mainly in Western, Nyanza and Coast provinces of Kenya. The total irrigated land at present is estimated at over 36,000 ha (IDRP, 1987).

Kenya does not have a long history of irrigation development like Egypt and other countries. However, traditional irrigation may have been practiced as far back as 400 years ago (IDRP, 1987). Flood irrigation, which is still being practiced by the Pokomo in lower Tana, may have started centuries ago. Records of the early Europeans settlers in the late 19th century gave impression of indigenous irrigation in Elgeyo Marakwet, West Pokot and Baringo Districts. Traditional irrigation is still continuing in the same areas for example Tot and Marigat areas.

Several irrigation schemes were established at the height of the Mau Mau Emergency. These include Perkerra, Mwea, Yatta Furrow, Tana River and Ishiara. Post independence irrigation development saw the establishment of a National Irrigation Board (NIB) in 1966 to administer the National Irrigation Schemes. Private large-scale irrigation is presently confined to coffee in the rainfall deficit agro-ecological zones, pineapples and horticulture. There are also alot of small-scale irrigation schemes, which concentrate on horticultural crops.

Since 1977, small-scale irrigation development in both the medium and low potential areas has been slow but steady. The Ministry of Water Development (MoWD) has broad responsibilities in the development of Kenya's water resources. It has overall responsibility for the allocation of water for irrigation and any other use through the Water Apportionment Board, and is engaged in detailed investigation and planning for water development on national scale. The MoWD maintains an 'Irrigation and Reclamation Section' no doubt having its roots from the earlier times when the water section was moving from one department/ministry (Public Works, Natural Resources, Agriculture) to another until it settled as a Ministry of Water Development in 1974. In the establishment of the pre-independent national irrigation schemes, the Department of Public Works (Hydraulic Engineers) was responsible for engineering aspects, the Department of Agriculture for production and the Provincial Administration for labour and settlement matters. All these functions were transferred to the NIB on establishment in 1966.

[Table 3.2.1: Number of Irrigation Schemes in Kenya]

The above irrigation schemes vary in size from 1 ha to more than 20,000 ha. About 60% of the total number of schemes has area of less than 100 ha. Most of the irrigation methods used in the country are basin, furrow, and sprinkler or drip irrigation.

The major constraints encountered in irrigation schemes are:
a) Inadequate source of water
b) High cost of irrigation inputs
c) Lack of proper technical knowledge
d) High relief intensity
e) Sodic and saline soils
f) Salt affected water


Drainage

Toksoz (1981) estimated about 600,000 ha as the total agricultural land that requires drainage improvements and/or flood protection, while Inter-Ministerial Task Force estimates the land to be 208,000 ha. The already reclaimed land is about 2,000 ha.


3.1 > 3.


4.   Plant nutrient resources

4.1  Plant nutrient use and nutrient balance

4.2  Fertilizer production and costs

4. > top



4.1  Plant nutrient use and nutrient balance


Kenya imports all her fertilizer requirements and this has been supplied to the farmers at subsidized prices for along time. With supra nationally imposed structural adjustment policies, however, these subsidies were largely abolished in 1992 and the subsequent increases in fertilizer prices have shot up thus discouraging farmers to use the mineral fertilizers. Because of such developments, there is an increasing need to use external inputs such as organic manures.

[Table 4.1.1] shows the value of purchased fertilizers. The value of fertilizers sold declined by 12% from Ksh. 2,052 million in 1999 to Ksh. 1,805 million in year 2000.

[Table 4.1.1: Purchased mineral fertilizers during 1996-2000 in million Ksh]

According to Smaling (1993), the use of N, P, K fertilizers in Kenya was 62,718, 19,733 and 11,428 tons per year respectively, between July 1986 and June 1987

In the Kenyan market, there are several fertilizer grades which include:

I) Nitrogen fertilizers:
a) Ammonium fertilizers - for acid soils
b) Nitrate fertilizers e.g. Calcium Nitrate (16%N) - popular in floriculture sector.
c) Ammonium Nitrate fertilizers - eg Calcium Ammonium Nitrate (C.A.N. 26%N) for topdressing in acid soils and Ammonium Sulfate Nitrate (ASN 26% N) for topdressing in alkaline soils.
d) Amide fertilizers - The most common is Urea (46%N) and commonly used for sugarcane.
e) Multi-nutrient fertilizers in Kenya are mono-ammonium phosphate (MAP 11-52 0) and Diamonium Phosphate (DAP, 18-46-0), which are also sources of phosphorus and are widely used at planting stage.

II) Phosphates fertilizers
a) The two commonly used are single Super Phosphate (18% P2O5) and Triple Super Phosphate (46% P2O5)

III) N-P-K (compound fertilizers)
There are several grades but the most common ones are:
20-20-0, 25-5-5+5s (for tea crop), 20-10-10, 23-23-0 and 17-17-17

IV) Potassium fertilizers
The two most common in the market are Muriate of Potash (60% K2O) and Sulphate of Potash (50% K2O)

Long-term (more than three seasons) monitoring of the fertilizer use recommendations (FURP, 1994) on three soils revealed that the same amount of fertilizer gave entirely different yield response at three sites due to very different climatic conditions ([Table 4.1.2]). On a Nitisol, Phaeozem and Arenosol, maize grain yields were increased by 133% (on Nitisol), 40% (on Vertisol) and 48% (on Arenosol) through application of P only, of N only and N+P together respectively. This demonstrated the merits of zone specific and crop-specific fertilizer recommendations over blanket recommendations.

[Table 4.1.2: Yields and NPK uptake of maize on three Kenyan soils as a function of soil type and fertilizer treatment, 1990]

One of the biggest challenges facing agriculture in Kenya at the moment is to develop soil fertility restoration and nutrient saving technologies that are low cost, agronomically effective and socio-economically feasible. Production of major cereals (maize, wheat, rice, barley and sorghum) is primarily limited to the application of nitrogen or phosphorous. This means that the major nutrients have to be continuously applied to achieve good crop yields. For example, a district level study by Smaling (1993) for nutrient balances in Kisii showed much higher nutrient depletion of -112, -3 and -70 Kg/ha/yr of N, P and K respectively. These results indicate that all agricultural land uses in the mixed smallholder farming systems of the district cause high depletion of the major nutrients. Incorporation of the livestock-dairy enterprise was found to mitigate N and K depletion to some extent. Results from Kakamega District showed the most depleted nutrients were N (between -30 to -80 Kg/ha/yr, except in livestock incorporated farms) and P (-50 Kg/ha/yr especially in non- contracted sugarcane and maize- based farms). The study also suggested that commercial enterprises tend to contribute more to gross margin at the detriment of soil fertility depletion.

Potassium is found to be adequate for most soils in the country and this was attributed to parent materials, which are high in feldspars and micas, although research being conducted shows that potassium is becoming deficient in Kenyan soils. The author continues to say that analysis of 13 major agricultural soils in Kenya indicated that most of them have a low C reserve of up to 406mg Kg-1. It has also been found that among the trace elements, the most deficient is Cu especially in wheat fields. Nevertheless, very few studies have been carried out in Kenya on the status and the requirements of trace elements.

Nutrient balance studies in Kenya indicate that Nitrogen and Phosphorous are being depleted at a rate of 40-100 and 2-3 Kg ha-1 yr-1 respectively. However, in spite of the negative balances, some agro-systems are still productive. This is because soil fertility decline may not be noticed because of the soils high nutrient stocks and availability or imbalanced nutrient and unavailability of N/P ratios. Soil fertility decline starts to be noticed in systems with low nutrient stocks and availability (crop yields gradually going down). These studies show that unsuitability of agricultural production at national level corresponds with the observations at farmhouse hold level. Thus from the full balance calculations, the average N-balance at farm level is -71 Kg/ha-1/yr-1 with large variations between farms ranging from 240 Kg/ha-1/yr-1 to 135 Kg/ha/yr while the K-balance average is slightly negative in contrast to the P-balance found to be slightly positive (Nandwa et al., 1997). [Table 4.1.3] shows a nutrient balance of some land use types which indicate that more often than not, there are negative balances.

[Table 4.1.3: Nutrient balances of some land use types at farm level]

[Table 4.1.4: Types of nutrient flows at farm level]

Fertilizer recommendations in Kenya for wheat, barley and rice are regularly adjusted to address changing biophysical conditions. Blanket fertilizer recommendations for maize have remained in operation for a long time. Recent studies suggest that fertilizer recommendations based on limiting nutrients have much higher nutrient use efficiency than those of blanket recommendation (FURP, 1994). Apart from the use of other mineral fertilizers, several studies have been conducted on the effectiveness and efficiency of rock phosphate in comparison to processed P fertilizers (Woomer and Muchena, 1997).

The first over all conclusions derived from past studies is that amongst the East African rocks, Mijingu deposits on average reaches 65% of the effectiveness of processed P fertilizers (TSP) but only costs about 50% of it on a P2O5 basis (Woomer and Muchena. 1997). The second conclusion is that the benefits of phosphates rock application are greater and much more likely only on low pH and P limiting soils (Okalebo and Nandwa, 1997).

However, two major challenges facing Kenya is how to solve the problem of the low reactivity of its rock phosphate deposits (1.7 - 2.1%). The other challenge is the cost of freight for the rock phosphates from Tanzania (Minjingu) and Uganda (Busumba and Suku), which have been shown to increase maize yields by 1 - 3 tons/ha when applied at the rate of 400 Kg/ha (Minjingu) and in combination with organic sources of N. It therefore implies that the use of these products is limited to areas near the supply.

Lime and liming materials are often applied to reduce soil acidity so as to enhance availability of nutrients. The following [Table 4.1.5] shows the effect of soil pH on maize yields (Kg/ha) on three Kenyan sites (all on Acrisols) located on high, normal and low pH. The results show an upward trend in yields as the soils become more acidic.

[Table 4.1.5: Maize yields (Kg/ha) on three Kenyan sites located on high, normal, and low pH all located on Acrisols.]

In many agro-ecosystems in Kenya, organic inputs existing in farms are sometimes not fully exploited as nutrient inputs due to complex tradeoffs between costs (labour, land) and perceived benefits on a short and long-term basis. Nevertheless, organic inputs may include biomass transfer, agro-industrial by-products and wastes and cropping systems based on nitrogen fixation Nitrogen contribution by legumes and other N-fixing plants has been widely exploited in enhancing productivity of agro-ecosystems, in terms of species for intercropping, agro-forestry, rotational species or as species for use in improved fallow technology. (Nandwa et al; 1997). [Table 4.1.6] shows the fertilizer equivalences of different organic inputs with different organic inputs with differing quality in Kenya.

[Table 4.1.6: Fertilizer equivalencies of some organic inputs in Kenya]

Recent rising costs of mineral fertilizers has focused researches on recycling of crop and other plant residues and weeds as a strategy to buffer the level of soil fertility and maintain soil organic matter. For example, a 2 ton/ha-1 grain crop (4 tons/ha-1 stover) on average contains 25, 7.2 and 65 Kg/ha-1 of N, P2O5 and K20, respectively.


4.1 > 4.


4.2  Fertilizer production and costs


- - -


4.2 > 4.

5.   Hot spots

5.0  Overview: constraints to sustainable agriculture

5.1  Land-related constraints

5.2  Water-related constraints

5.3  Plant nutrition-related constraints

5.4  other constraints

5. > top



5.0  Overview


- - -


5.0 > 5.


5.1  Land-related constraints to sustainable agriculture

 

[Link 5.1.1 : LADA Case study Kenya with emphasis on salinization: Report and Maps] [new]

[Table 5.1.1] shows the major land-related constraints to sustainable agricultural production in Kenya and their approximate constraints and area covered.

[Table 5.1.1: Major land-related constraints to sustainable agricultural production in Kenya]

Other related constraints are:
a) Poor soil fertility due to continuous monoculture cropping
b) Low soil pH due to continuous use of acidic fertilizers
c) Lack of enough capital and proper inputs
d) Soil compaction and crusting, forming hardpan or plough layer due to continuous use of heavy machines especially in large-scale farms
e) Low soil moisture holding capacity
f) High cost of inputs
g) Pests and diseases
h) Erosional Hazard.

[Table 5.1.2: Different degree of desertification hazards in Kenya as per 1997]

5.1 > 5.


5.2  Water-related constraints to sustainable agriculture


a) Unreliable rainfall in 83% of the country to sustain crop production. b) Expensive irrigation materials, which most farmers cannot afford. c) Unreliable sources of water. d) Saline or sodic water. e) Steep slopes.


5.2 > 5.


5.3  Plant Nutrition-related constraints to sustainable agriculture


a) Nutrient depletion in the soils due to continuous cropping. This is due to parceling of small units of land for agricultural purposes and lack of proper dissemination of technologies by agricultural extension agents.
b) Due to population pressure, all the crop stovers are removed from the farms after harvesting and used either as animal fodder or as fuel.

[Table 5.3.1: A case study of nutrient removal by harvested maize and beans in Kenya in Kg/ha]


5.3 > 5.


5.4  Other constraints to sustainable agriculture

 

Other constraints related to agricultural production in the country are:
a) Poor infrastructure
b) Pests and diseases
c) High prices of inputs
d) Lack of capital
e) Poor prices of marketable products
f) Erosional Hazard.


5.4 > 5.

6.   Bright spots

6.0  Overview: society's response to ameliorate the situation

6.1  Land-related response indicators

6.2  Water-related response indicators

6.3  Plant nutrition-related response indicators

6.4  Other response indicators

6. > top



6.0  Overview: society's response to ameliorate the situation


- - -


6.0 > 6.


6.1  Land-related response indicators


The available land for sustainable agricultural development is 17% of the whole country. The land tenure is either freehold or lease from the government and registered under individual care. Arable farming is practiced either in large scale or small scale. Dairy farming and growing of cash crops is other land use type. For the remaining 83% of the country, which is either semi-arid or arid where pastoralism and tourism are the main land uses. Most of these areas are communally owned but sub-division of group ranches is continuing. A policy on intensive cultivation of arable land should be formulated. Idle land should be repossessed and be distributed to the farming and landless people.


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6.2  Water-related response indicators


For sustainable use of water resources, the government, through the assistance of donors and NGO's has encouraged the farmers to form societies where they are assisted in making dams and sinking of boreholes especially in arid and semi-arid areas. Where arable farming is practised, farmers have been encouraged to use different water harvesting techniques eg. Matengo pits developed in Katumani Dryland Research Center. For areas with sodic soils, planting of salt tolerant crops (eg mangroves which can provide firewood and building poles) is encouraged or the areas are left for other recreation purposes. For irrigation, the government has encouraged the farmers to use simple techniques eg. drip irrigation systems, which are cheap to buy, simple to use, and uses little water compared with others. Deforestation and clearing of water catchments areas should be avoided.


6.2 > 6.


6.3  Plant Nutrition-related response indicators


The Kenya Agricultural Research Institute has done research on fertilizers and the results have been recommended for different agro-ecological zones of the country. Early maturing crops, resistance crops to pests and diseases, drought tolerant (e.g. Makueni Composite and Coast Composite Maize) for dry areas and high yielding crops have also been approved for different regions of the country. Agricultural sustainability should become an integral part of land use policies. Integrated nutrient management should become a common practice and projects that address nutrient management e.g. increased fertilizer use efficiency, zero-grazing, rotations with N-fixing species, agroforestry and soil conservation etc. should be appreciated.

Frontline extension staff in conjunction with the researchers disseminates technologies developed by researchers. A link exists between the extension and research through the Research-Extension Liaison Offices in the districts who coordinate the dissemination activities. Up scaling of developed technologies is presently being done through Farmer Field Schools which is a concept introduced by FAO Office especially in the Western and Coast regions of Kenya.


6.3 > 6.


6.4  Other response indicators


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6.4 > 6.

7.   Challenges and viewpoints



The major challenges facing the agricultural production in Kenya is low rainfall in the arid and semi-arid lands to sustain agricultural production while in the medium to high potential areas the major problems are soil erosion, poor seeds quality, poor infrastructure, low soil fertility, leaching, low soil water holding capacity, lack of credit facilities to the farmers, population pressure on agricultural land and low technical knowledge on agricultural production and storage.

Through these challenges, the government has encouraged the farmers to form co-operative movements through which they can sell their agricultural products, access credit facilities, train the farmers on new techniques in agricultural production, irrigation, water harvesting, fertilizer applications and ways to market their products through avoidance of middlemen.


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8.   References and related internet links

8.1  References

8.2  Related internet links

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8.1  References


Cege, O.S. 1968. Kenya's water resources and their development. Hydro meteorological survey of the catchments of Lakes Victoria, Kyoga and Albert. Inauguration, 22nd March 1968: 46-52

Doorne, J.H. van. 1985. A review of small-scale irrigation schemes in Kenya. FAO, Rome

FAO. 1999. Integrated Soil Management For Sustainable Agriculture and Food Security In Southern And Eastern Africa (Proceeding of the Expert Consultation) Harare, Zimbabwe, 1997. Food and Agriculture Organisation of the United Nations, Rome.

FURP. 1994. Fertilizer Use Recommendation Project. Volume 3. Kenya Agricultural Research Institute (KARI).

GoK. 1983. Development Plan, 1984-1988. Government Printer, Nairobi. Government of Kenya.

GoK. 1985. An Interministerial Policy Task Force. Irrigation development in Kenya. Government of Kenya.

GoK. 1986. Economic management for renewed growth. Sessional paper No.1 of 1986. Government Printer, Nairobi. Government of Kenya

GoK. 1990. A policy framework and development programme, 1991-1996. Kenya Wildlife Service, Nairobi pp 1-148. Government of Kenya

GoK. 1992. National water master plan, 1992. The study on the National Water Master Plan. Department of Water, Nairobi . Government of Kenya

GoK. 1994. The Development plan 1994-1996. Government printer. Government of Kenya.

GoK. 1996. The Economic Survey 1996. Central Bureau of statistics. Nairobi, May 1996. Government of Kenya

GoK. 2000. The Economic Survey 1999. Central Bureau of statistics. Nairobi, 2000. Government of Kenya

GoK. 2000. Population Census. 1999. Central Bureau of Statistics. Government of Kenya

GoK. 2001. Economic Survey 2000. Central Bureau of Statistics. Government of Kenya

IDRP, 1987. National Irrigation and Drainage Research Proposal. Irrigation and Drainage Research Programme.

Kanyanjua, S.M. and G. Thuranira. 1998. Effects of fertilizer inputs on maize yields and chemical properties of selected Acrisols in Kenya. In: Proceedings of the 16th Conference of Soil Science Society of East Africa. 13th - 19th December, 1998, Tanga, Tanzania.

KARI, 2001. Fertilizer Use Manual. Soil Fertility and Plant Nutrition Research Programme, Kenya Agricultural Research Institute.

Kenya Meteorological Department. 1984. Climatological statistics for Kenya.

Kool, R and Schulze, F.E. 1975. Towards a comprehensive national program for research, training and project guidance in irrigation and drainage. Report of a visit to Kenya.

Ministry of Water Development. 1982. National Master Water Plan stage 1. Summary of technical results. Maji House, Nairobi, Kenya.

Mutuo, P., Marandu, A.E. and Rabeson R. 1998. Nitrogen fertilizer equivalency values of organic materials of differing quality. In: Proceedings of the Soil Science Society of E. Africa. 13th - 19th December, 1998, Tanga, Tanzania.

Nandwa, S.M., P.T. Gicheru, J.N. Qureshi, C. Kibunja and S. Makhoha. 1997. Kenya Report. In: Proceedings of the Expert Consultation on Integrated Soil Management for Sustainable Agriculture and Food Security in Southern and East Africa. Harare, Zimbabwe.

Okalebo, J.R. and Nandwa, S.M. 1997 Effect of organic resources, with and without inorganic fertilizers on maize yield mainly on P deficient soils. EAFRO for J. 43:75-83.

Smaling, E.M.A. 1993. An agro-ecological framework for integrated nutrient management with special reference to Kenya. PhD Thesis. Agricultural University, Wageningen, The Netherlands.

Sombroek, W.G., Braun, H.M.H. and B.J.A. van der Pow. 1982. Exploratory soil map and agroclimatic zone map of Kenya. Scale 1:1,00,000. Kenya Soil Survey Report No. E1, Nairobi.

Toksoz, S. 1981. Policy on an accelerated program on irrigation and drainage development in Kenya. Ministry of Agriculture, Nairobi.

Woomer, P.L. and F.N. Muchena (1997). Overcoming soil constraints in crop production in tropical Africa.


8.1 > 8.


8.2  Related internet links

Country in general

Kenya Facts and Figures
http://www.pbs.org/sixbillion/images/LHKenya.pdf


Land and Water resources

Land rights in Africa - Land use in Kenya
http://www.oxfam.org.uk/landrights/eafrica.htm#Kenya

"Devastating Drought in Kenya: Environmental Impacts and Responses"
http://www.unep.org/ROA/1/News/Devastating%20Drought%20in%20Kenya.htm

"Rehabilitating the Baringo Drylands of Kenya"
http://www.idrc.ca/reports/read_article_english.cfm?article_num=982


8.2 > 8.



history:

[09/05/02] on-line
[04/12/03]add link to LADA case study on 5.1.1
[29/07/04]add link to Directory of Soil Institutions and Experts in Africa on 2.2.1