Wind-proof Seedbed for Reducing Wind Damage at Early Germination Stage of Direct Sowing Sugar Beet

Abstract

Seedlings of direct sowing sugar beet cultivation are vulnerable to wind injury in the early stage of germination. Seedbeds prepared to shelter the young seedlings from strong wind are a possible wind-damage countermeasure. In the present study, effect of a wind-proof seedbed that has Λ-shaped ridges at both sides of the sowing position on wind proofing was examined by wind tunnel tests. Measurements were made of vertical wind velocity profile using hot-wire method, and of wind velocity vector using particle image velocimetry (PIV) technique in the vicinity of a wind-proof seedbed model. Wind flow characteristics above the seedbed were also modeled and simulated by Computational Fluid Dynamics (CFD) modeling. Based on the measured and simulated data, a seeder-mounted ridger was developed which can form the wind-proof seedbed with the Λ-shaped ridges with height of 5 cm. Field tests were conducted to measure and compare the wind velocity at different heights above the sowing position of the wind-proof seedbeds and conventional seedbeds. Test results showed that the wind velocity at an elevation of 1 cm above the sowing position of the wind-proof seedbed was reduced by 60 % in comparison with that of the conventional seedbed.