**5. Conclusion**

Composting is an inexpensive and sustainable treatment for solid organic wastes. The composting industry has been growing rapidly because of a boom in the animal industry in China over the past decades. In this chapter, we introduce composting process and status in China, especially in Jiangsu Province. Meanwhile, the developed novel spectroscopy techni‐ ques (i.e., NIRS-PLS and EEM-PARAFAC) are also introduced, which are more suitable for assessment of compost maturity than the conventional techniques in view of ease of sample preparation, rapid spectrum acquisition, nondestructive nature of the analysis, and the portability of the technology. In addition, organic fertilizer amendments can not only improve soil fertility but also offset chemical fertilizers' nanoscale changes. Recently, investigators have shown that organic fertilizer amendments could enhance the production of highly reactive minerals, for example, allophane, imogolite, and ferrihydrite, which further benefit for soil carbon storage and soil fertility improvement.
