Correlation circle crossing the first two components of the principal component analysis performed on the result performance indicators (53 in total) measured on plots. We represent here only the vectors whose cos² (relative contribution) is greater than or equal to 50%. Indicators whose name begins with "m." are those whose value has been modified by adding a minus sign so that the direction of the vector indicates an improvement in the desired performance. Thus the arrow for "m.N_miner" indicates the direction of the decrease in nitrogen use (Tab. 6).