Fig. 5

Diagram of the principal component analysis (PCA) of the phospholipid fatty acids (PLFAs). NT, no-tillage; ET, earthworm bio-tillage; RT, traditional rotary tillage; None, without OM input; Straw, straw return; CM, cow manure addition. G+, gram-positive bacteria; G-, gram-negative bacteria; F/B, the ratio of fungi to bacteria; G+/G-, the ratio of G + to G-.