Homogeneous fields are very rare in nature.
In most cases, productivity varies within a single field. There’s nothing we can do about it. As a result, the only thing that’s left to do is to work with heterogeneous fields. Productivity zones in the same field may vary from year to year.
I usually divide the fields into two types of fields: ones with stable and unstable productivity zones. The productivity zone features in the first kind of fields are not affected by either weather conditions or cultivated crop features. In this case, the field itself has a factor or factors that limit the yield. For example, their influence exceeds the influence of humid or dry weather.
For the second type of field, productivity zone features vary from year to year. During one variable-rate sowing experiment I conducted last year
, I saw how a moderate productivity zone became a high productivity zone after harvest. This is an example of the second type of field. In unstable fields, the yield is primarily affected by weather conditions or by cultivated crop features instead of internal factors.
It is essential to determine whether the field is stable or unstable to be able to interpret the results well. It is very easy to make a mistake when identifying productivity zones.
The field’s heterogeneity is characterized by its productivity zones. There are several ways to identify them. You can use soil analysis data, vegetation data, or yield data over multiple years. All methods are good if you know the factor that limits the yield on your field. But that’s not always the case.
The most surefire way to identify productivity zones is to use yield maps over at least three last years. Doing so will help you ensure you know whether or not the productivity zones are stable and be able to spot these zones in the field. Important! The yield data should be precise. The combines are calibrated to extract this data.