Haque, M.E., Esdaile, R.J., Kabir, E., Vance, W., Bell, R.W., Musa, A.M., Shahidullah, A.K.M., Nobi Mia, M.N., Maruffuzaman, M. and Johansen, C. (2010) Minimum-tillage, mechanized sowing of pulses with two-wheel tractors. In: Gilkes RJ, Prakongkep N, editors. Proceedings of the 19th World Congress of Soil Science; Soil Solutions for a Changing World; Published on DVD; http://www.iuss.org, 1 - 6 August, Brisbane, Australia, pp 156-159.
Pulse crops in Bangladesh are mainly low-input rainfed crops with broadcast sowing. Since the 1990s, rotary tillage two-wheel tractors (2WT) have largely replaced animal draft for crop establishment. However, rotary tillage causes excessive evaporation from seedbeds in rapidly-drying soils. Therefore 2WT-based minimum tillage (MT) options were explored to optimize seedbed moisture for lentil and chickpea establishment. Two types of 2WT-mounted seeding units were manufactured, a strip tiller retaining rotary blades only in front of the tynes and a tyne seeder in which the rotary tiller shaft is removed. In some soil types, seedling emergence and grain yields of lentil and chickpea with these seeders matched those with broadcasting. In wet soils, the minimal soil disturbance with MT resulted in anaerobic conditions around seedling roots thereby limiting root growth and nodulation. In clay soils with rapid surface drying traction was inadequate for tyne tillage and strip tillage could not adequately penetrate rice paddy hardpans to allow adequate growth of seedling roots. Potential solutions to these limitations are under test so that 2WT-based MT can be adapted for more timely and economic sowing of crops, including pulses, in smallholder plots and to achieve the agronomic benefits of line sowing over broadcast sowing.