Fluorescence Spectroscopy and ¹³C NMR Spectroscopy Characteristics of HA in Black Soil at Different Corn Straw Returning Modes

Figure 3

Fluorescence spectra of HA in different maize returning methods on subsoil. Note. CK: no straw application; SCR: straw mulching; MBR: straw deep ploughing; SEDI: straw enrichment and deep incorporation. (a) Subsoil: CK. (b) Subsoil: SCR. (c) Subsoil: MBR. (d) Subsoil: SEDI.

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