Figure 4. TEM images of the soil FAs from the NPK (a–b) and SM (d–e) treatments during a long-term (i.e., 22-year) fertilization experiment.

Selected area electron diffraction (SAED) patterns of the two images indicated by the blue squares, demonstrate that the black regions are polycrystal (c) or short-ranged-order (SRO) (f) minerals. NPK, chemical nitrogen, phosphorus and potassium; SM, swine manure. (g) and (h) energy dispersive X-ray spectroscopy (EDS) of region 1 and 2 located at the red square frames.