The assessment is performed for all experimental farms. The scientific principles of the 4R Nutrient Stewardsheep framework include:

1. Right Source - ensure a balanced supply of essential nutrients, considering both naturally available sources and the characteristics of specific products, in plant available forms

2. Right Rate - assess and make decisions based on soil nutrient supply and plant demand

3. Right Time - assess and make decisions based on the dynamics of crop uptake, soil supply, nutrient loss risks, and field operation logistics

4. Right Place - adress root-soil dynamics and nutrient movement, and manage spatial variability within the field to meet site-specific crop needs and limit potential losses from the field.

Appropriate guidelines and evaluations of GHG emission and economics will be consulted to the farm managers.