TITLE:
Simulating Nitrogen and Irrigation Effects on Wheat Production in Bangladesh under Changing Climate
AUTHORS:
Ranjit Sen, Apurba Kanti Choudhury, Sohela Akhter, Sheikh Ishtiaque, Md. Abu Hena Sorwar Jahan, Faruque Ahmed, Jatish Chandra Biswas, Md. Maniruzzaman, Md. Main Uddin Miah, Md. Mizanur Rahman, Naveen Kalra, Md. Abdul Aziz, A. S. M. Mahbubur Rahman Khan
KEYWORDS:
Climate Change, Wheat, Temperature Rise, Irrigation, Nitrogen, Bangladesh
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.7,
June
22,
2017
ABSTRACT: Climate change impacts are visible in Bangladesh which requires adoption of judicious crop management
practices for sustainable agriculture. Crop simulation models are effective in
this regard and can be used for optimizing water and nitrogen inputs for
maximization of wheat yields. Two field studies were conducted at Bangladesh
Agricultural Research Institute (BARI) for evaluating the effect of increased
temperature on wheat production under variable water and N rates, through the
use of DSSAT v4.6 model. Thirty years historic weather data and BARI Gom-26
wheat-cultivar coefficients, as generated through use of GLUE of DSSAT model,
were used for evaluating the impact of temperature rise with variable rates of
irrigation water and nitrogen. The effects of four levels of nitrogen (0, 40,
80 and 120 kg ha-1) and four irrigation levels [0 (no irrigation), 1,
2 and 3] on wheat yield were evaluated under 0°C, 1°C, 2°C
and 3°C rise in temperature. Simulation results indicated that wheat
yield increased with increase in nitrogen application rate, but decreased with
the temperature rise. Crop growing duration was reduced by about five days for
each degree rise in temperature, irrespective of levels of irrigation water and
nitrogen-rates. In general, there was yield reduction of 8.13, 16.77 and 24.97
% with increased temperature of 1°C, 2°C and 3°C,
respectively, when compared with no temperature rise treatment. For interaction
of temperature rise-N dose, the magnitude of yield decline under temperature
rise was higher with increased dose of N. Agronomic
N use efficiency at different N rates and temperature rise level were
calculated. N use efficiency decreases with the increase in temperature rise
and the highest (29.95 kg grain kg-1 N) was
obtained from 40 kg N ha-1 treated plot with 0°C temperature
rise i.e. existing atmospheric
temperature. Simulation results indicated
increase in wheat yield with higher levels of irrigation water, and interaction
of irrigation level with temperature rise was significant. Irrigation
use efficiency decreases with
the increase in temperature rise. From the present study, it was seen that the
interaction of temperature rise with varying levels of N and irrigation water
was significant, and there is a need to design the appropriate inputs’
management, as the adaptation strategy, to sustain the wheat yield under climate
change situation.