Short-Term Response of Soil Organic Carbon Indices to Different Farming Strategies and Crop Rotation Systems in a Semiarid Warm Region

Figure 4

(a) represents the Pearson correlations between carbon (C) fractions consisting of: labile C and non-labile-C, lability index and C pool index with the C management index. and ^ns indicate significant and non-significant correlations between the parameters. (b) represents the matrix of partial correlation analysis between LI (lability index), CPI (C pool index) with CMI (C management index) under different C inputs as: three farming strategies: SIF_no-CR (inorganic fertilizer, no return of crop residues to the soil), SOF_30% CR (organic fertilizer, returning 30% of crop residues), and IOF_15% CR (integrated use of organic/inorganic fertilizers, returning 15% of crop residues) and four crop rotation systems: mung bean-wheat (B-W), corn-wheat (C-W), sesame-wheat (S-W), and fallow-wheat (F-W).

(a)

(b)