Tuesday, September 10, 2013

Planting winter wheat into dry soil

Dry soil conditions have sparked many questions from growers on how best to establish their winter wheat crop. As we were reminded last year and this there is no substitute for rain (unless you have irrigation), however here are a few ideas to consider to mitigate your risk.
  • Conserve soil moisture. If possible no-till your winter wheat. If this is not possible due to equipment limitations, limit your tillage passes across the field. 
  • Increase your seeding depth (e.g. plant to moisture). As stated in the Top 7 Recommendations for winter Wheat Establishment: Wheat should be planted ~1.0 inch deep depending upon soil moisture conditions. Wheat planted more than 1.5 inches deep may result in death due to pre-mature leaf opening or poor tiller development and winter survival. 
    • As a grower there is little you can due to prevent pre-mature leaf opening. This phenomenon is rare unless seeded extremely deep and compaction also occurs. 
    • You can increase tiller development or effective head number by increasing your seeding rate. 
    • I do not have yield loss or winter kill data implicitly from seeding depth experiments however deep seeding will delay emergence which may be similar to delayed planting. Data from our 2009 Lancaster and Arlington WI planting date experiments show that yield and winter survival decreased as planting date was delayed (Table 1.).
    • Deeper planting may expose germinating and emerging wheat seed to greater potential for herbicide carryover. However if you explicitly followed the herbicide label restrictions for rotational crops you have a basis to contact the company if problems occur. Remember the label is the law.   
Table 1. Planting date effect on grain yield and winter survival at Lancaster and Arlington WI, 2009.
Lancaster, WI
Planting date Grain yield (bu/a) Winter survival (%)
17-Sep 74.9 88.5
30-Sep 68.3 70.0
13-Oct 54.2 58.0
Arlington, WI
Planting date Grain yield (bu/a) Winter survival (%)
18-Sep 101.9 83.8
1-Oct 93.3 55.3
17-Oct 73.9 30.
  • Remember to use a fungicide seed treatment. Even though you are planting into dry soil and the overall pathogen load may be lessened, you are planting deeper and delaying emergence especially as soil temps continue to decrease. 
  • Remember your crop insurance and planting date restrictions. In a spring seeded crop we would often say wait until it rains to establish the crop however we have a short window to get the crop established and still get your full crop insurance coverage. Please talk to your crop insurance agent for specific dates for your county.