Abstract:
The present study was initiated with aim of investigating the importance of homegarden
agroforestry on improving soil properties with specific objective of evaluating selected
physico-chemical properties under homegarden agroforestry and to compare with adjacent
land use at Yayu district, Southwestern Ethiopia. Representative soil samples were taken
from homegarden agroforestry with different age classes; new (Nh), established (Eh) and old
homegarden (Oh), and from adjacent land of open cultivated land (Ocl), semiforest (Sf) and
natural forest (Nf). Samples were collected in each site of soil sampling in Zigzag method
from plot of 20mX20m at each soil depth of 0-30cm and 30-60cm by three replications, totally
of thirty six composite soil samples were collected for analysis. Soil data was subjected to
analysis of variance using the GLM procedure of the SAS version 9.3 and LSD test were used
to compare treatment means at 0.05. The result showed significant difference in soil
parameters analyzed.Considering the topsoil, the highest soil pH(6.06), available
P(23.17ppm) and exchangeable K(6.53cmol(+)Kg-1
)was obtained inold homegarden
agroforestry, whereas the lowest (5.40), (5.81ppm) and (1.45 cmol(+)Kg-1
)was in open
cultivated land, in respectively. Regards to subsoil, the highest soil pH(6.18) available P
(8.97ppm) and exchangeable (K 2.01 cmol(+)Kg-1
) in homegarden agroforestry, whereas
5.63, (2.34ppm) and (0.51 cmol(+)Kg-1
) respectively.Available p and exchangeable k was
highly significantly associated with soil pH value at r=0.78** and 0.73** in topsoil,
r=0.71**and r=0.87** in subsoil at p<0.05, in respectively. This soils property improvement
in the soils of homegardens may perhaps due to house refuses bones and ash, animals
manures, contribute of crop residues and litterfall to form SOM; as SOM mineralization form
inorganic matter, and humification and buffering capacity of SOM; as it optimizes soil basic
cations. Hence it can be concluded that, the soils in the homegarden agroforestry posses the
improving trend in soils properties as compared to the adjacent land uses soils. Therefore the
homegarden agroforestry practices that has been started and ongoing by the smallholder
farmers for ancient time in Yayu district should be considered by NutriHAF and Government
to scaling up the practices. Further, detail investigation on soils and plant nutrient analysis is
important to clarify the impact of homegarden agroforestry on soil.
