The most recent drought monitor still shows much of Western South Dakota in varying stages of drought with the worst conditions centered on eastern Meade and Pennington into Haakon and Ziebach counties. As a result, many farmers may find themselves planting winter wheat into dry soils, which poses a number of challenging options that should be considered.
In the Western part of the state, the ideal winter wheat planting window ranges from around September 15th through the first week of October. Planting later than this increases the risk of poor stand quality and yield declines. Previous research suggests a 5-10 bushel decrease over a five-year study period.
However, if timely rains fail to materialize, the logical choice may be to wait to plant until there is more soil moisture to help the germinating seed. If this is the case, it is important to understand the risk to wheat yield.
In general, there are two concerns with late-planted winter wheat. The first is that the plant does not have sufficient time for early crown and root development, which increases susceptibility to winterkill. If we have a mild winter, the yield effects may be minimal, but this is difficult to predict. Adequate phosphorus and nitrogen starter can help improve early root growth and increased seeding rates can make up for poor emergence and winterkill losses.
A second potential issue caused by later plantings is delayed maturity. The later wheat is planted, the further it is behind in the spring. Slower development leads to delayed flowering and grain filling, which generally corresponds to the hotter, drier period in the following summer. Again, if heat and moisture stress is minimal at this time, the yield impact is lessened. However, the likelihood of both a mild winter and a moderate, moist June and July in Western South Dakota is slim for any given year.
Even if dry conditions persist, small adjustments can make a big difference next summer. Planting depth should be modified along with seeding rate to accommodate dry soil. Deeper planting depths may help the seed find moisture, but there is always a concern of the seedling running out of energy before it emerges when planted too deep. Increasing seeding rates can help make up some of the difference, but this also increases seed cost. Site selection is also extremely important. Where there is more residue, there is likely to be more soil moisture and also increased protection from the extreme winter cold.