Editor’s note: The following was written by Mark Licht, assistant professor and Extension cropping systems specialist with Iowa State University, for the university’s Integrated Pest Management website Feb. 18.
The fall of 2018 was challenging for most farmers. It started with rainfall beginning in early September as the corn and soybean crop was maturing. While a good portion of the crop was harvested, rain and cold temperatures limited fall tillage operations.
This presents an opportunity to save money on input costs this spring.
Soybean does not have a yield response to tillage. This is good news. There is no need to spend labor and fuel incorporating the corn residue. On top of that, spring tillage operations are not effective for breaking soil compaction. In fact, the opposite happens in normal spring conditions when soil moisture is plentiful.
Spring tillage in wetter conditions leads to smearing of soil from the tillage knives or sweeps and disking creates a compaction layer while sizing residue.
There may be a need for some spot tillage to fill ruts created during harvest. This should be limited to the areas with ruts. Shallow tillage is adequate. Deep tillage will likely not reach the full depth of compaction and, because of spring soil moisture, will make the compaction problem worse.
The essential part of no-till planting is to ensure proper function of the planter. This is not different from any other tillage system. Confirm appropriate row unit down pressure, check seed placement depth, and ensure furrow closure.
No-tilling corn and soybean does require more finesse but with some patience will provide dividends at harvest.
No-till soybeans into corn
I have talked to a couple farmers who have experience with no-tillage planting. It was unanimous that any planter purchased in the last 20 years can plant soybean into corn residue without any trouble, especially if the planter already has row cleaners.
Nearly all planters have the ability to ensure appropriate down pressure and seed depth placement. Research from across Iowa shows that soybean yield is not influenced by tillage system. Therefore, no-till planting soybean into corn residue will yield similar to other tillage systems but also result in high economic returns.
No-till corn into soybean
Since soybean residue is fragile and less abundant than corn residue, today’s planters can easily move through the field with little to no reduction in typical planting speed.
Row cleaners should be set to “tickle” the soil which will easily move soybean residue out of the row.
Using injected spring nitrogen to prepare a seedbed similar to strip-tillage is a good option but should be conducted seven to 14 days ahead of planting and ideally have a gentle rain to avoid burning corn seedling roots.
No-till corn into corn
Planting corn into corn residue is more complicated than no-tillage planting corn into soybean residue. In this situation, light tillage such as a rotary harrow or vertical tillage implement may be necessary.
It is going to be important to use row cleaners to move residue out of the row. Having the ability to use starter fertilizer can help lessen early season growth challenges often associated with corn following corn.
If fall anhydrous was delayed, using RTK can be an effective way to form a tillage zone similar to strip-tillage. If doing this, be cautious of high nitrogen rates burning corn seedling roots. Waiting seven to 14 days between anhydrous application and planting (and a gentle rain) along with injecting slightly deeper can reduce issues with this practice.
- Wait for fit soil conditions.
- Like any new practice, start slow to gain confidence then increase the speed.
- Set row cleaners to move residue, not make a trench.
- Check planter performance and seed placement often.