The force needed for breaking and cutting of winter wheat and spring barley straw

Abstract

When applying soil, environment and energy sustaining tillage and drilling technologies, cultivation and seed incorporation become more complex. Crop residues left on the soil surface have a considerable influence on the process of tillage and drilling machinery operation. They aggravate the operation of tillage and especially that of drill coulters. Most often soil, environment and energy sustaining tillage and drilling technologies use disc coulters which can cut, break or press crop residues into the notch made by the coulter in the soil while interacting with the soil surface. The objective of this work is to investigate the forces of breaking or cutting fresh or overwintered straw of winter wheat and spring barley influencing the process of tillage and drilling machinery operation. Research on cutting and breaking crop residues was carried out during the period of 2011–2012 in the Tribology Laboratory of Aleksandras Stulginskis University. The fresh straw of winter wheat and spring barley of 22% moisture content and overwintered straw of 5% moisture content with nodes and without nodes were used for the research. Our research evidenced that the crop residues of spring barley were easier to break compared with those of winter wheat. About 160 N force is needed to break fresh straw of winter wheat with nodes or without them compared with the analogous type of spring barley straw – about 53 N force. Great influence on breaking characteristics is made by leaving the crop residues to overwinter on the soil surface. However, the research showed that the characteristics of the winter wheat and spring barley crop residues left to overwinter vary unevenly. The force for breaking the overwintered winter wheat straw decreases by about 3.2 times compared with the fresh straw of winter wheat and the force for breaking the straw of overwintered spring barley decreases by 34%. The research on cutting crop residues with a knife simulating a disc coulter showed that the cutting of the fresh and overwintered crop residues of winter wheat and spring barley at the node and other section of the straw differs signally. In order to cut the fresh straw of winter wheat and spring barley at the node 35 to 43 N weaker force is required compared to cutting at other sections of the straw. To cut the overwintered straw of spring barley and winter wheat at the node 18% to 30% weaker force is required compared with the fresh straw. During the cutting at the node the straw of winter wheat and spring barley is deformed less and more slowly compared to solid straw without nodes.