Machinery Insider Tip: Size Up Your Field to Select Tillage Approach
Consider soil condition (including drainage and texture), residue level, and slope erosion when selecting tillage approaches, explains Jodi DeJong-Hughes of the University of Minnesota.
This is how the engineer ranks the action of shanks, coulters, and disks on tillage equipment:
• Shanks will dig into the hardest, driest, toughest soil. On a field cultivator, they do a nice job of mixing soil and fertilizer on top while taking out weeds.
• Coulters with waves and fluted edges are great for sizing residue and mixing a little soil. Because they are straight up and down, they tend to bounce along on dry soil without digging. “Don’t ask them to penetrate dry ground or fully incorporate anything,” DeJong-Hughes adds.
• Disks are intended for slicing residue, breaking clods, and burying residue. The deeper the concavity of a disk, the better it can cope with slicing while sweeping through hard soil, and the better it is at breaking clods.
Although they have a place and purpose, she dislikes disks as shallow-tillage tools. “While disks are wonderful at cutting up residue, corn chopping heads have reduced their usefulness. Disks are very destructive to soil structure. If you use them, keep them shallow,” she advises.
When wetland needs to be dried quickly, DeJong-Huges prefers vertical-till tools with coulters. “A vertical-till machine can get through wet soil without mudding up. It introduces air, and it doesn’t go very deep. But you don’t have to create a seedbed – 2 to 3 inches is great. Farmers have found that if they run it twice and wait a few days in between, they can plant,” she notes. “It chops really well and throws things up and down, but it doesn’t do a lot of mixing or incorporating. Plus, you can run at 8 mph to 11 mph.”
Field cultivators remain a good option for good field conditions and somewhat drier soil. However, in wet soil they can create a shallow-tillage pan that hinders downward root growth. Shanks tend to go under and pick up clods in hard, compacted soil.