We haven’t given a rip about deep tillage on our farm for a few years. As we continue to move towards more acres in a no-till system with the rest of the farm in minimum till we traded in our 9 shank ripper a few years back. At an auction in March 2013 we bought a 5 shank ripper for the farm. So what exactly is a ripper, and why go back to using one as we look to reduce tillage over our operation? Brian and Darren Hefty of Ag PhD offer a good explanation of what deep tillage is and why farmers use this practice.
Since we’ve traded off our old ripper we believe some of the most traveled parts of our fields could use a little help battling soil compaction. Let’s take a closer look at our new tool which is an Unverferth 130 Zone Builder. This is the front of the implement. A coulter in front of each shank cuts a relatively shallow path ahead of the shank. The coulter also slices crop residue so it can slide on past the shank instead of hanging up and creating a mess. Each shank is spring-loaded so it can trip whenever it finds a large rock. And when you start ripping you will find rocks! Gauge wheels on the ends help maintain the depth. This 5 shank implement will cover the tracks of our tractors. We may look into adding on two more shanks because that width would cover the wheel tracks of the combine as well. A side view shows the shanks and springs hanging off the back off the toolbar. The springs are inside the black tubes. This ripper is an inline version with straight shanks and no wings on the teeth. In the past we’ve used rippers with curved shanks and winged teeth. That style heaves up a lot more soil instead of just slicing through, but this time we want less disturbance on top of the ground so we hopefully won’t have to do additional spring tillage ahead of planting in our no-till fields. I guess if the ripper goes out in any of those fields they’ll be just somewhat no-till. With previous rippers we would have to perform additional tillage to level the seedbed for planting. Subsoiling in generally done in the fall, so what we do disturbed on top ought to settle by spring. So with our new ripper we are looking to alleviate soil compaction selectively in certain fields. Compacted soil layers inhibit root growth which limits the ability of a crop to locate water and nutrients. We used to rip about a third or so of our acres every year going across entire fields. Now we just want to hit high traffic areas in our fields and maybe wet spots because machinery isn’t the only source of soil compaction. Areas that pond frequently can be compacted from the weight of water sitting on the soil for an extended period.
Our yield maps give us some clues as to where we might want to run the ripper. Harvest equipment is the worst offender when it comes to soil compaction. Combines and grain carts are the heaviest pieces of equipment to cross a field during the year, and since we’ve quit ripping it seems the areas most traveled are beginning to show effects of soil compaction.
The areas highlighted by the red ovals on this map tell us we might be seeing some compaction issues in the fairly straight areas of yellow and orange. The strip running North and South is along a gravel lane behind our shop. Trucks park on the lane where they are loaded with grain from the combine or grain cart meaning the soil adjacent to the lane sees a high level of heavily weighted traffic in addition to regular traffic of planting, tillage, harvest, and so on. The other oval is showing what I’ve starting calling the “grain cart highway.” The grain cart travels across these rows dozens of times during harvest to get back to the end of the lane from the far side of the field. There’s no doubt we have a compaction problem here, and we don’t need a yield map to know that. Of course compaction can’t be totally eliminated, but it can be mitigated. I’m sure you’ve noticed there are other yellow and orange areas in this field indicating similar yields. These would correlate better to soil type and slope as they don’t see excessive traffic like the areas I highlighted. An example from another field may show the effects of compaction more clearly. This is a small field just under 30 acres. The field above contains around 200 acres. This yield map makes it pretty obvious that compaction is occurring around the field edges where machinery travels most often. The North end is generally where we park trucks on the road to load our grain. This end sees the most traffic, and you can see there is a pretty clear-cut difference in yield between the end rows and the center of the field. We sometimes load out along the East road. The West is bordered by an open ditch and the South side butts up to a neighbor’s field. So in this field the areas we ought to go out and rip are easy to see. End rows and field borders don’t always do as well as the rest of a field, but I think these are areas where we need to do something about compaction due to the volume of traffic these acres experience through the course of a year. Now performing deep tillage with a ripper (also called a subsoiler) isn’t going to clear up all our compaction issues. The effects of breaking the hard pan below the top few inches of soil might last a few years at best. Therefore, we need to be diligent and try to do things like deep the grain cart limited to staying on the combine tracks instead of cutting an angle across the field because that path is faster. Ripping won’t be and shouldn’t be our only tool to fight back compaction. Since we’ve gone to less tillage in recent years we are making less passes over our fields which should limit compaction on the majority of acres within a field. By introducing cover crops on 20% of the farm we are using the roots of the covers as our deep tillage tools. They may not have the immediate effect of steel in the soil, but their benefits should be longer lasting not to mention the potential for increased yield and reduced inputs. We can also do a better job of controlling field traffic by taking the extra effort to drive across tracks we’ve already made versus cutting a new path just because it’s easier. Hopefully by investing in the ripper we’ll see some improvement in yield on our field edges and high traffic zones. And with GPS auto steer in place we can send it out across a field to just hit wheel tracks by dialing up either our planting or harvest tracks. So instead of ripping a whole field we’ll just hit the spots we drive on. Here’s to a yield bump in years to come!