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. That presents an opportunity to save money on input costs this spring.
Soybean doesn’t have a yield response to tillage. That’s good news. There’s no need to spend labor and fuel incorporating the corn residue. And spring tillage operations are not effective for avoiding 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; disking creates a compaction layer.
There may be a need for some spot tillage to fill ruts created during harvest. That should be limited to the areas with ruts in order to fill them. 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. That’s 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.
Plant soybeans using no-till
I have talked to a couple of farmers who have experience with no-tillage planting. It was unanimous that any planter purchased in the past 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 shows 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 good economic returns.
No-till plant corn into soybean residue
Because 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 it should be conducted seven to 14 days ahead of planting and ideally have a gentle rain to avoid burning corn-seedling roots.
into corn residue
Planting corn into corn residue is more complicated than no-tillage planting corn into soybean residue. Light tillage such as a rotary harrow or a vertical-tillage implement may be necessary. It’s 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 real-time kinematic can be an effective way to form a tillage zone similar to strip-tillage. If doing that be cautious of increased 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 that practice.
Visit crops.extension.iastate.edu for more information.