Read your Pre-Planting Weather Report like a pro to optimize your season and improve yields.
1. Find the Winning Planting Temperatures in Your State in 2015
Data on yield and planting soil temperature in your state can give you some important insight into how farmers in your area made that planting date decision last year, and how that turned out. An interesting bit of insight from Illinois, for example, is that though most farmers planted between 50°-55° F, there was a 3 bu/A advantage to planting in at 45°-50° F (the second most popular temperature).By checking the “Distribution of Planting Temperatures” graph, you can see the percent of analyzed acres that were planted in each temperature range.
2. The Highest Yielding Growing Seasons are Not Necessarily the Longest
Do longer growing seasons always increase yields? The interesting thing we’ve found is that a longer growing season doesn’t always (or necessarily) lead to a higher yields. For example, the data for corn in Illinois in 2015 showed that, though the highest absolute yields were achieved between 170-175 days, comparably good yields were achieved between 155-160 days. The 155-160 day timeframe actually outperformed the 160-165 day timeframe by 7 bu/A in Illinois in 2015, and even slightly outperformed the 165-170 day timeframe by 1 bu/A.
3. Use Freeze Risk Estimates to Adjust Your Planting and Harvest Timing
Understanding historical freeze risk (based on the 15 year average) can help you understand and avoid the risk of suffering a damaging freeze event during germination and emergence. Plus, it’s important to take freeze risk into account as you plan the order in which to plant your fields. If you manage fields that are miles apart, historical freeze risk at the field-level can help you tailor your planting practices to the needs of each field’s geography and climate.
For these graphs, with an April 1st planting date, there is about a 100% freeze risk, but by April 15th, it's dropped to 20%, and by May 15th to 0%. Harvesting around October 15th on the other hand puts the freeze risk at around 50%, whereas an October 1st harvest date reduces it to 0%.
4. Plot Your Expected Precipitation and GDUs Based on Your Planting Timing
Use the Growing Degree Units (GDUs) and Precipitation graphs to understand how many GDUs and how much rainfall you can expect on each field given your planting and harvest date. You can then check the optimal GDU and Precipitation performance for your seeds in Seed Finder to determine what planting and harvest dates will get you into your seeds’ sweet spot. In the example graphs below, an April 15th planting date and October 15th harvest date will likely bring you about 3200 GDUs in your season as well as 24 inches of precipitation.
For more information on using growing degree units to plan for your growing season, see the Growing Degree Units and Corn Emergence page at UNL’s Cropwatch.