I spent Thursday this week in Lac Qui Parle County with around 250 growers looking at soil, tillage and the impact our choices make on field productivity. The event was a University of Minnesota field day, sponsored in part by soybean check off along with other commodity groups and industry.
Seeing that large of a group of farmers fully engaged in the presentations was exciting and demonstrates the kind of investment the Production Action Team is making in getting good information out to Minnesota farmers. This is the kind of field day that would be great to expand to three sites next year to better assist our growers with strong options for tillage and soil management across the state. Several important messages that I heard from the sessions throughout the day involved what you as growers can do to help improve your field productivity in the area of tillage and soil management. For example; it had rained recently and conditions were not optimum for demonstrating field tillage equipment but it was a great opportunity to demonstrate the message of waiting for the right field conditions. Tilling in field conditions that are too wet can result in large clods that will require further operations to reduce their size, as well as glazing of the soil as the equipment passes through the soil. Glazing essentially polishes the soil and reduces water movement. Every tillage pass through a field changes the soil structure, which in turn impacts water and fertilizer movement.
Hal Weiser with North Dakota NRCS showed photographs of plant root zones where the crop had developed few roots in the shallow tillage zone precisely where most of the applied fertilizer would be found in any given year. He reported that this condition is exacerbated in dry years. Soil compaction was a second topic University of Minnesota Regional Extension Educator Jodi DeJong-Hughes covered. In some areas of the state, saturated soil conditions would lead to wheel ruts from equipment if harvest were to happen today. Jodi talked about the difference between soil compaction and the soil condition in those wheel ruts. She indicated that soil compaction is defined as the loss of air space in soil due to damage to the soil structure. Since saturated soils have those voids normally filled with air now filled with water, the rutting in the field is not soil compaction and is best remediated by freeze/thaw fracture, not by tilling through it. During the day I also spoke briefly with Dr. Abbey Wick from NDSU whose work focuses on soils and soil health. Dr. Wick is a collaborator with Jodi DeJong-Hughes on a larger project that the Production Action Team through MSR&PC supports with a component of the funding.
Dr. Wick is the primary investigator with the NDSU SHARE farm (http://www.smallgrains.org/2013Conf/Wick2013PGConf.pdf). NDSU also has a web site focused on soil and soil health research (www.ndsu.edu/soilhealth)worth taking a look at when you have time. Keep this bookmarked as another resource for information on soil, tillage and soil health questions as they arise in your operation.
In a follow up on variety selection from last week, be sure to look at the kinds of resistance genetics available for any particular trait you are adding in your cultivar choices. Look for, or ask your seed sales person about the IDC tolerance ratings in lines that indicate they have it and ask for an explanation of how that ranking works as there are several methods used by individual companies. When looking for SCN resistance, be sure to ask for cultivars that allow you to rotate the SCN resistance mechanisms to slow the loss of effectiveness of a particular genetics due to over use. Look for aphid resistant cultivars that use pyramided genes when possible to provide more effective resistance as well. Finally, keep in mind that using conventional lines versus herbicide resistant cultivars may provide an economic balance in production profitability. They may also give you a weed control option in specific fields where herbicide resistant weeds are becoming problematic. The job of evaluating each field for specific needs and matching the best yield potential/trait combination package to each field is a large, but important component to raising the overall profit potential of your soybean farming operation as you start making plans for next year.