Understanding Research Statistics
Dr. Charlie Wortmann, UNL Extension Soil Fertility Specialist, explains the power of statistics for understanding yield and other differences and non-differences for on-farm research.
Research Fertilizer Options for Your Farm
November 1 is just around the corner-the beginning of when fall fertilizing occurs in this area of the State. Hopefully many of you have taken soil samples as excess nitrate is to be expected after this drought year. This is an excellent time to consider evaluating your nitrogen program by starting an on-farm research trial!
On-farm research is using your own equipment, in your own fields, over single or multiple growing seasons allowing you to determine the most economical, efficient, and sustainable practice for the production of irrigated and/or dryland crops on your own farm.
What are the soil fertility questions you have for your farm?
Right now, with fertilizing on producers’ minds, we’re hoping you will consider a soil fertility study. We have several example nutrient protocols including the UNL N fertility rate compared to +/- 30 lbs, and considerations for nitrogen timing studies such as pre-plant, sidedress, or fertigation. You can view all these plot designs by clicking on 2012 protocols. If you are planning on applying anhydrous this fall, be sure that the anhydrous strips are the correct width, as the corn must be harvested and weight determined in a correct manner next fall.
When designing a nitrogen comparison you need to remember nitrogen is a mobile nutrient and corn roots will spread laterally. Therefore, the width of the treatments must take this into account and compensate for it. If you have a 16 row nitrogen applicator and an 8 row corn head, you will need 32 rows of each nitrogen rate. Each 32 row strip must be repeated 4 times. At harvest, in each 32 row block, you must record and weigh the center 16 rows with two separate weights i.e. 8+8 . This is done for statistical analysis purposes. Without statistics, you cannot determine if differences between treatments is the result of the nitrogen rate or because of soil variability.
What’s in It for You?
On-farm research in your own fields allows you to find answers to the questions you may have. We all read articles or hear presentations about various practices and products. The question is “Will it work on my farm?“. That’s what on-farm research allows you to find out!
UNL Extension Educators and Specialists are here to help you design your on-farm research trials, help you with data collection, and will statistically analyze the data for you at the end of the season. Correct plot setup is critical to reduce any error in favoring one treatment over another (because we know fields are variable and some portions of the field will yield better than others). The statistical analysis is another tool which helps us determine how much any yield differences between treatments are due to the treatments themselves or to chance.
So if you have an idea you’d like to try, please contact any of the UNL Extension Educators or Specialists working with on-farm research! The Nebraska On-farm Research Effort is a partnership between the Nebraska Corn Board, Nebraska Corn Growers Association, and UNL Extension.
On-farm research may sound daunting, but today’s equipment makes it easier than ever. It does take a little extra time, but our farmers conducting on-farm research feel the value of knowing the results of a study on their own piece of ground make the effort worthwhile.