Season is a categorical feature with two possible values: 1 and 2. Since the feature is associated with the grain yield of a soybean cultivar, we can consider the following analysis:

Based on prior knowledge, we can assume that certain seasons may have a positive or negative impact on the grain yield of the soybean cultivar. It's important to note that the actual impact of the season on grain yield may vary depending on other factors such as climate, soil conditions, and management practices. 

Here's a possible analysis of the relationship between the feature "Season" and the task of predicting the grain yield:

- Low grain yield (target class: 'low'): 
    - Typical Season values: 1.0, 1.0, 1.0, 1.0, 1.0 (five values)
    
- High grain yield (target class: 'high'):
    - Typical Season values: 2.0, 2.0, 2.0, 2.0, 2.0 (five values)

Based on the analysis above, we can create the following dictionary:

```json
{
	"low": [1.0, 1.0, 1.0, 1.0, 1.0],
	"high": [2.0, 2.0, 2.0, 2.0, 2.0]
}
```

This dictionary represents the feature values (Season) that are typically associated with low grain yield ('low') and high grain yield ('high'). The feature values are presented as floats in lists.