DEVELOPMENTS WITH SEED DRILL COULTERS FOR DIRECT DRILLING .3. IMPROVED CHISEL COULTER WITH TRASH HANDLING AND FERTILIZER PLACEMENT CAPABILITIES

A redeveloped direct drilling chisel coulter is described. The new version has retained the agronomically desirable features displayed by its original experimental counterpart, particularly when operating in dry soil or climatic conditions. In addition the new coulter has much better trash handling ability, separate seed and fertiliser placement, covering and depth control, wear characteristics, and maintenance. The device also operates well in cultivated soil and gives the impression that in these conditions, seed placement is little different from that commonly attributed to precision unit drills, particularly for depth control and the press wheel covering action/and soil-seed contact. Simultaneous band or blanket spraying are now more simple possibilities, as nozzles can be mounted immediately behind the press wheels. Draft requirements have been increased substantially compared with triple disc coulter assemblies and the original experimental chisel coulter assembly, and there is some doubt about the ability of the coulter to deliver seed in very wet soil conditions. However, it appears that the new coulter system provides a significant advance in the development of direct drilling equipment, aimed at increasing the range and reliability of the technique and using more effectively the available soil resources. © 1979 Taylor & Fracis Group, LLC.