Blade edges wear and should be kept pinched together at the soil entry point to prevent soil and residue from plugging the opener. At other times, a single leading coulter is useful to cut residue ahead of the seed opener. If a coulter is required to cut through residue, additional weight may be needed for penetration. Engineers with the USDA Soil Tilth Lab found the vertical force to keep a single coulter in the soil was 100 to 200 pounds, but could be up to 400 to 600 pounds in difficult conditions. Operating the coulter only deep enough to cut residue minimized the weight requirement and helps to ensure seed contact with firm soil.
Some growers prefer to use a fluted coulter to disturb a wider band of soil in the row area.
There is a tendency, however, for soil loosened by fluted coulters to be thrown out of the row by the coulter or seed opener when planter operating speeds are greater than 5 miles per hour. This usually occurs when soil sticks between wider fluted undulations at the edge of the coulter. A leading single coulter to cut residue is usually not necessary for the staggered or offset seed opener. Figure 3 not available. Types of row cleaning devices.