In agriculture, we spend a lot of time with data — collecting it, analyzing it, debating it, and using it for decision making. A recurring point of interest, particularly in the world of agronomy, is where the data is from and how it was collected. When we consider the relevance of data generated in a more controlled environment like a greenhouse or dairy barn, it can be easier to discern the applicability of the results to other facilities with the same or very similar design and management.
In contrast, given the influence of growing environment on crop performance, it can be more challenging to determine what data is most relevant, and for this reason, value is often assigned to local data. But does a local source boost the value of this data?
In true cooperative extension fashion, the answer is “It depends,” but in all cases, understanding the context is needed.
Weather and climate impacts
Seasonal weather conditions have a significant impact on crop performance, both agronomically (including emergence, growth rate, grain development, and yield) and in terms of forage quality (such as fiber digestibility and grain development in corn silage). However, given the hyper-localized weather patterns in many areas, the location closest to your farm does not necessarily provide the most relevant data.
When assessing data from crop performance trials, there can be greater value in data from locations with similar weather conditions, even if these locations are some distance away or from a previous growing season. They can be more relevant to your situation than the closest location geographically.
In contrast to seasonal weather patterns, more general climate factors based on geographic region can have a greater impact. A crop well-suited for one area of the country may not achieve the same potential in another area. An obvious example of this is selecting the proper relative maturity for corn.
An interesting example related to forage quality was shared by a colleague who participated in a multi-state evaluation of meadow fescue grass. The three states involved were in the Northeast, North Central, and Southeastern areas of the country. In the two more northern locations, the forage quality potential of the meadow fescue was similar and quite high. In contrast, the same varieties of grass grown in the Southeast performed quite differently and did not show the same quality potential, likely related to differences in temperatures.
Consider cropping system
The amount of information available for our major field crops is mindboggling, and the majority of this is sound information; however, this does not mean it applies to your situation. With corn, we often talk about the intended use (grain or silage) as a factor in management. Understanding the cropping system the guidelines are designed for, though, is critically important. There are meaningful differences in management between a typical row crop rotation with no manure inputs and a more typical dairy situation with corn grown in rotation with perennial forages with routine manure inputs. Guidelines for different systems can appear to contradict each other, and both can be correct within the correct context.
Remember soil resources
Soil type, as well as underlying parent materials, has a significant impact on many soil fertility guidelines affecting a range of factors, including nitrogen supplying potential to the soil’s impact on plant availability to pH management. When reviewing soil fertility recommendations, it is critical to ask questions and verify the data is relevant to the soils — both specific soil type and broader geological classification — on your farm or in your region.
Given the diversity in soil types, particularly in areas influenced by glaciation, a cropping practice may not be a fit for your soil resources even when it is successful on a neighboring farm.
