TITLE:
Demonstrating Effect of Rainfall Characteristics on Wheat Yield: Case of Sinana District, South Eastern Ethiopia
AUTHORS:
Fitsum Bekele, Diriba Korecha, Lisanework Negatu
KEYWORDS:
CSIRO-Mk3.6.0, Impact, Kiremt (JJAS), Wheat Yield
JOURNAL NAME:
Agricultural Sciences,
Vol.8 No.5,
May
22,
2017
ABSTRACT: Demonstrating Effects of Current and Projected Rainfall Characteristics
on Wheat yield has been investigated in Sinana district for the period
1995-2016. Data on rainfall and crop yield for the period 1995-2016 were
obtained from National Meteorological Agency and Sinana District Agricultural
Offices, respectively. Following data quality checking, rainfall data (current
and future), correlation and regression studies were analyzed using Statistical
software like Instat V3.36 and SPSS V20. Downscaling the output of
CSIRO-Mk3.6.0 GCM model (daily rainfall data) for RCP8.5 emission scenario
using a web based software tool (Marksim GCM) for the period 2020-2049 were
used to determine seasonal total rainfall and ascertain its impact on yield.
This study used mean, coefficient of variation, correlation and regression
analysis to ascertain the relation, cause and effect relationship between
rainfall characteristics and wheat yields. The results indicated that the mean
onset date of the main rainy season (JJAS) for Robe and Sinana station was June
30 and July 3. Furthermore, the results of Pearson Correlation Coefficients
indicated that kiremt rainfall total (JJAS) had moderate positive relationship
(r = 0.499) with wheat yield in the study area. It was also observed that
nearly fifty percent of total variance of crop yield is explained jointly by
kiremt rainfall total and rainy day (R2 value was 47.9%). The result of
projected wheat yield indicated that there will be a slight decrease in wheat
yield (qt/ha) after 2030 years due to the impact of expected weakening of
kiremt rainfall total. Taking in to account the above findings, it could be
suggested that the farmers’ community will be encouraged encouraged to utilize
timely climate information issued from National Meteorological Agency of
Ethiopia (NMA) and other centers for farm level decision to enhance their crop
production.