Using the concept of minimum dataset which consisted of
selecting the most appropriate indicators that point to the proper
functioning of Soil, we choose four indicators for about two per
correlated group. The choice was based on the length of vector in
the multi-dimensional space spanned that represent indicator, and
on the close relation between them. pHw, and Ca from correlated
group 1 and OMand available P from correlated group 2. They have
been used in combination when computing SQI4 and SQI2
(Table A4). For assessing soil quality, soil parameters or indicator
can be used individually or in combination