```json
{
	"low": [1.0, 1.2, 1.4, 1.6, 1.8],
	"high": [2.5, 2.8, 3.0, 3.2, 3.5]
}
```
Based on prior knowledge, a low grain yield in soybean cultivars is typically associated with a lower number of grains per pod (NS), while a high grain yield is associated with a higher number of grains per pod. The values in the "low" section represent typical NS values for soybean cultivars with low grain yield, while the values in the "high" section represent typical NS values for cultivars with high grain yield. The specific values provided in the dictionary are just examples and may vary depending on the context.