Figure 5.

Structural equation model (SEM) analysis of the transformation of different P components with the addition of animal manures in paddy soil under the flooded condition (a) and upland condition (b). Optimal model fitting results under the flooded condition (a): χ² = 2.618, df = 5, χ²/df = 0.524, P = 0.759, and RMSEA = 0.000; optimal model fitting results under the upland condition (b): χ² = 1.463, df = 5, χ²/df = 0.293, P = 0.917, and RMSEA = 0.000. The number on the arrow represents the standardized path coefficient, the red and blue arrows represent the positive and negative effects, respectively, and the thickness of the arrow represents the size of the impact effect.