The drought monitor for this week remains essentially unchanged. This is likely due to the precipitation received last week and moderate temperatures. Whether conditions change for better or worse depends on the weather this winter. The 30 day temperature forecast, predicts a strong chance of above normal temperatures with equal chances of above or below normal precipitation. Remember, we are heading into the driest period of the year with liquid precipitation averaging about one inch for December and January in this area. The 90 day forecast calls for equal chances of above or below normal temperatures and precipitation through February. Naturally, this is subject to change. Today’s topic regards the information overload crop producers may experience this and every winter.
If you pay attention to Ag news services, from K-State and the USDA to private companies, you will find a plethora of data coming out from last year’s growing season. Hybrids and varieties were evaluated. Herbicide and fertilizer efficacy trials conducted. Information on social media and in print/ audio are starting to come out. Public and private companies will hold many update meetings. So today, it might be helpful to provide a few hints and caveats on how to interpret the data.
• K-State Research and Extension has a crop performance testing program with results available here: https://www.agronomy.k-state.edu/services/crop-performance-tests/index.html. Tests are conducted around the state, some dryland only and some dryland and irrigated. Crops tested include wheat, corn, grain sorghum, soybean, sunflower, canola, and summer annual forages. Depending on the crop there are locations around the state with some on K-State research facilities and some on producer sites. The next bullet points explains the value of this research.
• Without diving into the weeds too deeply, this is replicated testing that can be statistically analyzed providing an LSD (Least Significant Difference) of 5%. In English, if the varieties/hybrids differ by more than this number the yield differences are significant. Look for cultivars that have been in the test for several years and sites that are the closest to your field conditions. The downside is these tests only include cultivars entered by companies in most cases and there may not be a site close to your operation.
• Last week, the area extension office reported the results of their grain sorghum strip test. Private companies also conduct these strip tests. Typically, these tests are not replicated and so no statistical analysis is possible, although K-State often pools locations across the state and uses each site a replication. Sometimes this process works well and sometimes it’s a bit sketchy. This isn’t to demean the work or results. It’s just that care must be taken in using these results.
• The private company tests, whether for crops, herbicides, or fertilizers may provide useful data but use extreme caution when interpreting these results. Some are replicated tests where they apply statistical analysis while other are simple strip tests. Read the fine print on how the test(s) was/were conducted (planting date and rate, fertility, irrigation, etc.). When graphs are presented, look at the actual numbers and pay less attention to the graph. For herbicide efficacy tests, closely examine how they evaluated efficacy/weed control, rates, timing of application, and other factors.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.