Dr. M. H. Ali
SSO
BINA
A.K.M. Adham
Assistant Prof.
IWM, BAU
Solar radiation, Dry-matter production, Comilla, Bangladesh
Crop-Soil-Water Management
, Weather/Climate
Solar radiation and other climatic data were collected from Bangladesh Meteorological Department. Yield data was taken from the Annual Report of Bangladesh Institute of Nuclear Agriculture (BINA, 2004).
Dry matter calculation: Dry matter production for a particular crop season was calculated as (Adapted from Ghuman and Singh, 1993):
DM = AE x Ep x Cd ................................................ (1)
Where, DM = dry-matter production, Mg/m2-day
AE = available solar energy, MJ/m2-day
Ep = photosynthetic efficiency
Cd = energy needed (MJ) to produce 1 gm dry-matter
For field crop, photosynthetic efficiency (Ep) was taken as 6.6 %, and energy needed to produce 1 gm dry-matter of field crop was taken as 4226 cal (0.01768 MJ) (Mitsui et al., 1977).
The increased production percentage (Pp) was calculated as:
Pp = 100(Production gap between potential and present drymatter )/ (Present drymatter production)
Calculation of atmospheric (extraterrestrial) radiation: The extraterrestrial radiation was calculated following the procedure of Smith et al. (1992):
Crop season: Three crops were reported in cropping pattern for Comilla, mustard (Nov. – Jan), Boro (Jan. – May.) and T. aman (July -Oct.) [BINA, 2004]. The effective growth period (for capturing solar energy) for mustard was taken as 67 days (out of 95 days), for Boro it was taken as 115 days of growth period (out of 155 days) and for T. aman it was taken as 108 days (out of 135 days of growth period).
J. Bangladesh Agril. Univ. 3(1): 149 – 154, (2005)
Journal