Multi-Year Prediction of Wheat Yield as Influenced by Changing Agro-Climatic Indices in Kapilvastu Using Dssat Crop Model
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Hydrology and Meteorology
Abstract
Central Terai in Nepal is the major production domain of wheat; however, wheat yields
have been majorly affected by anomalies of agro-climatic indices like fluctuating
maximum and minimum temperatures, solar radiation and rainfall. NASA Power data over
33 years records (1985-2018) were purposively download and compared with the ground
station measured data for the study of study by using four years of weather data (1986,
1996, 2006 and 2016) randomly selected years for the multi-year prediction of agroclimatic
scenarios on yields of wheat in Kapilvastu district, of Central Terai, Nepal. The
relationship between the DHM recorded weather data and the NASA power data was found
fairly valid and safe to see the long-term climate change impacts. At Kapilvastu the annual
average and maximum temperatures were found to be decreasing by 0.017˚C and 0.046˚C
per year, respectively, whereas the minimum temperature was increasing by 0.011˚C.
Similarly, the total precipitation was increased by 28.63mm per year and solar radiation
was decreasing by 0.035 MJm
-2
per year. The trend analysis on grain yields of wheat were
correlated over the historical records of maximum temperature, minimum temperature,
rainfall and solar radiations. A positive correlation was found with minimum temperature
and rainfall. However, the yield was found to be negatively correlated with the maximum
temperature and solar radiations. Cropping Systems model CERES-Wheat embedded in
Decision Support System for Agro-technology Transform (DSSAT) ver 4.7 model was
used to study the multi-year prediction of wheat yield over the changing agro-climatic
scenarios after following IPCC (2007) scenario using environmental modification section
of the DSSAT ver 4.7 models. The data sets to run the CSM-CERES- Wheat models have
been taken from the well predicted and validated crop model with WK-1204 cultivar of
wheat which is popularly grown in Terai and hills condition of sandy-clay loam soil,
resembling the production domain of the project sites. The simulation results using DSSAT
model over the 33 years of weather data were found to be very closely agreeing with the
observed data of the wheat yield recorded from the Ministry of Agriculture and Livestock
Development in Nepal. The trend analysis, regression and correlation studies and from
sensitivity analysis using DSSAT, all have resulted the uniform relationship between agroclimatic
indices
and
wheat
yields.
The
different
climate
change
scenarios
as
advocated
by
IPCC
(2007)
for
2020,
2050,
and
2080
were
studied
to
simulate
the
yield
performance
of
WK-1204
cultivar
of
wheat.
Increased
in
temperature
by
1˚C
will
increase
the
wheat
yield
and
furthermore
increased
in temperature decreased the yield under the present levels of
agronomic management options. The result showed that the wheat yields for few years can
only be sustained by using the present crop varieties and urged for the development of
climate change ready crop varieties to feed the increasingly growing population.
Keywords: Agro-climatic indices, DSSAT 4.7 crop model, Multi-year prediction, Wheat
yield
v
Description
Keywords
Agro-climatic indices, DSSAT 4.7 crop model, Multi-year prediction, Wheat yield