Influence of soil hardness on traction force of different design coulters

Abstract

No-tillage technologies have been developed in the world and in Lithuania at the same time, because of economical and environmentally-friendly advantages. However, the sowing into no-plowing and completely undeveloped soils is more complex because plant residues prevent in the soil. Using no-tillage technology, the soil surface is usually much harder if compared with tillage soils. Therefore, the sowing coulter in no-tillage soils has more difficulty in penetrating into the soil and ensuring the required sowing depth. The soil hardness also has an unavoidable influence on tillage and traction forces of sowing coulters. The research aim is to determine the influence of soil hardness of different tillage on the traction force of various coulters. The tests were carried out in three variants. In the first version the soil surface was loosened by the vertical rotary cultivator, in the second version it was loosened by the vertical rotary cultivator and compressed two times by a plain roller of 1000 kg mass, in the third version it was compressed six times by the plain roller. The tests were carried out with two different coulters: hob and complex, which consisted of two disc and hob coulters. The coulters were pulled at the speed of 1.39 m·s-1, the traction force was measured by six sensors, three of which measured the horizontal force, two measured the vertical force and one measured the lateral force. The tests have shown that to pull the complex coulter less traction force is required than to pull the hob coulter independent on the soil hardness.