TITLE:
Soil Organic Carbon Storage, N Stock and Base Cations of Shade Coffee, Khat and Sugarcane for Andisols in South Ethiopia
AUTHORS:
Bekele Lemma
KEYWORDS:
Annual Maize, CEC, Perennial Crops, Soil Nitrogen, Wondo Genet
JOURNAL NAME:
Open Journal of Soil Science,
Vol.8 No.1,
January
19,
2018
ABSTRACT: In the Wondo Genet,
Ethiopia, the common agricultural land uses include maize, shade coffee, khat
and sugarcane. The objective of this study was to examine the impact of
perennial land uses on soil organic carbon (SOC),
soil N and base cations. Four sites
having maize and one or two of perennial land uses
and with similar site characteristics were identified for this study. Soils (0 - 30 cm) were sampled at corners of a plot (20 × 20 m2) placed in
each land use at each site. Results indicated that the SOC storage of the shade coffee plantations were 86% and 125%
higher compared with adjacent maize land uses with the absolute differences
being 50.7 and 54.4 Mg·ha-1, respectively. The soil N stock was 109% and 126% higher for the
shade coffee than the maize land use while the absolute differences were 5.7
and 4.7 Mg·ha-1 for the same sites. Among perennials, the higher SOC storage in the shade coffee is
attributable to the increased litter input and reduced soil disturbance in the
system. While the higher soil N in
the shade coffee was attributed to reduction of leaching, N uplift, and the increased litter quality and input. The high
relative increase in shade coffee in SOC and soil N at Finance site was
ascribed to the finer soil texture and low SOC and soil N at the compared adjacent
maize farm. Although not significant, the relative increase in SOC (34%) and soil N (43%) in the sugarcane at the Finance as well as the relative
increase in SOC (7%) and soil N (9%) in khat at Gotu as compared to
Chaffee site was attributed to mainly the management differences. The shade
coffee has the greatest potential for SOC storage and for increasing N stock,
while khat and sugarcane have the least potential.