Climate

http://i1.trekearth.com/photos/112254/kenya_1_093-4.jpg

Nyeri + Othaya

http://pdf.wri.org/kenya_atlas_11_uppertana_ch8_300.pdf

• Altitude: 1500-2000m • Annual Rainfall 1200-1600mm in 4/5 yrs

(PA=1022mm)• Cold to warm, wet, medium altitude region• Nyeri district = 3,356sq.km land, 0km water

District of Nyerihttp://t2.gstatic.com/images?q=tbn:ANd9GcQndni_sC8BAcBMxArG_9ZtiYI6EDSs36PZdPTnIgu0pLG5JUoz

FAO

Nyeri Othaya•Classification: semi-humid•Annual Average Rainfall (mm): 800-1400•Average Annual Potential Evaporation: 1450-2200•Vegetation: Dry forest + moist woodland•Potential for Plant Growth: medium-high•Risk of Failure of an Adapted Maize Crop: fairly low (5-10%)•Mean annual Temp (C): 16-18•Mean Max Temp: 22-24•Mean Min Temp: 10-12•Abs. Min Temp: 2-4•Night Frost: Very Rare

•Classification: sub-humid•Annual Average Rainfall (mm): 1000-1600•Average Annual Potential Evaporation: 1300-2100•Vegetation: moist and dry forest•Potential for Plant Growth: high•Risk of Failure of an Adapted Maize Crop: very low (1-5%)•Mean annual Temp (C): 16-18•Mean Max Temp: 22-24•Mean Min Temp: 10-12•Abs. Min Temp: 2-4•Night Frost: Very Rare

Data from 1980 Map

ElevationFAO: 1996

Precipitation

FAO:-Last updated in 2000-averaged over 37 years

Nyeri Othaya Nyeri Othaya

2001Elevation: 1500-1800m 1800-2100m

1961

The probability of obtaining less than 20in (500mm) of rain a year 0-10% 0-10%

The probability of obtaining less than 30in (760mm) of rain a year 20-30% 0-10%

1961Mean Annual Rainfall 760-1010mm 1010-1270mm

Info from maps in PSU Library

Precipitation- Nyeri

Harvesting/Land Prep Planting Harvesting/ Land Preparation Planting

Long Rains

Short Rains

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec0

20

40

60

80

100

120

140

160

180

200

25 30

89

178

130

3825

3823

7689

76

Mean Monthly Rainfall

Month

Rain

fall

(mm

) -1961 Map in PSU Library-average of 6 years

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec0

20

40

60

80

100

120

140

160

180

200

25 30

89

178

130

3825

3823

7689

76

Mean Monthly Rainfall

Month

Rain

fall

(mm

)

-1961 Map in PSU Library-average of 6 years

myweather2:No information provide on time period from which the data was collected

Rainy Days

myweather2

Humidity

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec0

102030405060708090

Average Daily Relative Humidity

Month

Rela

tive

Hum

idity

(%)

myweather2

Temperature

FAO:-Last updated in 1991-averaged over 37 years

Temperature- Nyerimyweather2

Nyeri and Othaya (1980)•Mean annual Temp (C): 16-18•Mean Max Temp: 22-24•Mean Min Temp: 10-12•Abs. Min Temp: 2-4•Night Frost: Very Rare

Wind

myweather2

Length of Growing Period

FAO:-Last updated in 2000-averaged over 37 years

Kenya Soils

3 major soil orders

•Oxisols•Ultisols•Alfisols

Oxisols

• Strongly weathered• Little texture variation

with depth• Clay sized Fe and Al

oxides• Very red due the

presence of Fe

Ultisols

• “red clay soils”• High clay in B horizon• Acidic• Leached• <35% base saturation• Deficient in calcium and

potassium

Alfisols

• High clay in B horizon• ≥ 35% base saturation • Form in semi-arid to

humid areas• Generally drier areas

than oxisols & ultisols• Moderate to high

fertility

Natural Vegetation

What to find…

http://ecodiv.org/trapnell/trapnellol.html

Othaya: Moist Montane Forest

• Highly diverse in species– Potential for ecotourism– Many diverse tree species

help with agro forestry, food diversification, new crop potential

• Patches of wetland and open grassland

• Higher rainfall

Nyeri: Dry Intermediate Forest

• Not as diverse or productive in tree growth• Dry grassland present• Does have native medicinal trees – Combretum molle (Swahili: Mlama)• Quick growing• Good for burning, tool implements• Parts used for treating snakebites, hookworm, stomach pains etc.

Water Conservation

Water Conservation:The Need

• Difficulty growing crops

• Rainfall becoming more unreliable

• Land degradation• Loss of nutrients

http://www.sustainabilityninja.com/wp-content/uploads/2009/04/river-drying-up.jpg

Water Conservation:Loss of water

• Major causes:– Overgrazing– Deforestation– Tillage– Over cropping

Water Conservation:Existing Methods

• (NOT very widespread)• Rooftop water harvesting• Retention pits• Reduced Tillage

Water Conservation: Potential Methods

• Cover crops• Replanting trees (Agro forestry)• Rotational grazing• Crop rotation• Mulching• Build up soil structure• Increase existing methods

Rotational Grazing

• Rotate pastures and animals– Cow– Pig– Goat/Sheep– Chicken