42 It’s Farming. And It’s Better. Better Farming | April 2024 crops: yield matter$ A LOOK AT BASIC YIELD MAP ANALYSIS Last year’s results offer insight on yield ranges, & production patterns emerge. By Dale Cowan Yield monitors on combines have been around since the late 1990s. The monitor technology has steadily improved over time. The calibration and capture of relevant yield data have become easier to collect and share. However, the number of yield maps that get looked at after harvest by producers remains relatively low. When it comes to crop planning for next year, often last year’s results can offer some insight on yield ranges and definitive production patterns emerge. Looking at several years of data using a normalized yield function can help sort out production zones that are always high-yielding and zones that are perennially low-yielding, with a few flex acres in the field that may fit neither scenario. Let’s start with the simplest of observations. Every map maker will tell you a map needs a title, scale, compass, legend, and latitude and longitude. Most farmers recognize the shape and location of their own fields, so a lot of those other map attributes are glossed over. It is the legend that provides the most relevant information. Often, colours are assigned to the legend with yield ranges that correspond to the colours on the map. In addition, most ag software adds in some basic statistics on average yield and yield ranges. This facilitates a quick understanding of yield distribution across the field landscape. Interpreting a yield map is often considered complicated, but it does not have to be. The farmer knows his own field the best and can often tell you about what happens on every acre; deep black soil profiles, shallow sandy knolls, drainage issues, nutrient levels, if site-specific soil testing has been completed, etc. All these attributes can impact crop performance. Consulting a trusted crop advisor can help make some sense out of the yield data. Often, high soil test values are associated with low-yield areas, and low soil test values are associated with high-yield areas. If the strategy has been to apply a fixed rate of fertilizer in a highly variable field, then it stands to reason that low-yield areas are being over-fertilized and high-yield areas may be under-fertilized. The first option may be to use both the soil test and yield map to create a more prescriptive rate of fertilizer and use variable rate technology to apply the nutrients where needed to optimize the return on nutrient investment. The 4R nutrient stewardship principles can be met as long as timing and placement are optimal. On corn, the other layer that accompanies the yield map is the harvest moisture map. Often the yield and moisture are inversely related: High yields associated with lower harvest moistures and, conversely, lower yields with higher moistures at harvest. This may take some more thought and analysis. It has been my experience that crop emergence uniformity may be a factor here, as the lower-yielding areas may Looking at several years of data using a normalized yield function can help sort out which production zones are higher yielding. Geoff Small/E+ photo
RkJQdWJsaXNoZXIy NTc0MDI3