Aerodynamic properties of green gram sown in different environments in Indo-Gangetic Plains of West Bengal

摘要

Field experiments were conducted on green gram during spring-summer seasons of 2011 and 2012 with four dates of sowing and five varieties arranged in a strip-plot design to study the aerodynamic characteristics of green gram at BCKV, Kalyani, West Bengal. Micro-cup anemometers were placed at 0.5, 1.0, 1.5, 2.0 and 2.5 m above the crop canopy on a wooden mast. The zero-plane displacement (d), roughness length (Z(0)) and drag coefficient (C-d) were found to increase with crop age but the effect of dates of sowing was not prominent except at the final stage of growth. For a LAI value of 1.5, "d" values was 0.254 m and the "C-d" value was 0.015. Both the "C-d" and "d" increased with plant height and LAI. The "d" and "Z(0)" had significant positive correlation with the total dry matter and crop growth rate irrespective of dates of sowing.