Relationship between land use change, soil fertility and erosion across different agro-ecological zones in south eastern slopes of mt. Kenya

followed by soils under dairy, maize, tea and horticulture in LHp which had over 200% A study was conducted along two line of threshold level sac in soils and it was transects in Embu-Mbeere Districts to lowest in LMs under all existing land uses. Investigate the relationship between land use Available P (P. Olsen) was lower than the change, soil fertility and erosion across threshold levels under all land uses across differentagro-eco1ogica1 zones on the slopes all agroeco10gica1 zones. These observed of Mt. Kenya. The study involved soil variations of soil fertility indicators with sampling for fertility evaluation and erosion agroeco10gica1 zones was attributed to assessment within land use types found in different land uses in the same agro¬the prevailing agro-eco10gica1 zones along ecological zone, climate and decreasing the two transects. The study revealed that amounts of rainfall down the agroeco10gica1 soil fertility indicators (available P, Soil zone 1 to 7 which led to decreased leaching Organic Carbon (SaC) and exchangeable of basic cations and hence the increase in soil acidity (hp) decreased down the soil pH and sum of exchangeable cations agroecological zones 9TA,LH UM UM (Ca, Mg and K). The variations of available 1 I' 2¬14' LM), LM4 and LMs) while soil acidity P (P. Olsen), total Soil Organic Carbon (pH) and sum of basic cations increased. (SaC) and exch. K with land uses across There was insignificant change in nitrogen agroeco10gica1 zones was attributed to bound in the soil organic carbon although fertilizer inputs, nutrient recycling through sac decreased significantly with increasing litter fall, amount of nutrients in the litter and dryness as indicated by change of climate which influences soil organic matter agroecologica1 zones from TA to LM When turnoverrates in soils. Erosionquantification s. available P, total sac, and exchangeable K was attributed to topography, change in land were expressed as percentage of respective use and change in soil properties (soil threshold levels in the soils across various organic carbon content and textural land uses and agroeco10gica1 zones, the change). Erosion was found to be virtually results revealed that, there was significantl yzero at TA, and variable in UM , UM 1 2+J+4 more exch. K in soils cropped with coffee and LMJ and more quantifiable in LM4 and in UM2 (650% ofthreshold level) followed LMs. This trend of erosion observation by soils under maize in UMl and under followed soil susceptibility to erosion, which bushland which had exch. Kover 350% of increased with decreasing soil organic the soil threshold level. sac was significantly carbon content and change in soil texture more (over 350% of threshold level) in soils from more clay soils at higher altitudes to under forest in Tropical A1phine (TA) sandy soils at lower altitude zones. It was concluded that land use and climate change significantly affect soil fertility indicators along the study transect in Embu-Mbeere Districts while erosion preference was more controlled by land topography and change in land use than soil properties.