Effects of Auricularia auricula residue on soil physicochemical properties, microbial community composition and diversity, and rice yield

The return of mushroom residue to the field is an effective measure to improve soil fertility and maintain agroecosystem productivity. We investigated the effects of returning Auricularia auricula residue to the field on the soil nutrients, enzyme activities, and microbial communities in a rice– A. auricula rotation farmland. The trial was designed with three treatments: K0 (no mushroom residue), F1 (3600 kg/667 m² residue), and F2 (4500 kg/667 m² residue). The return of A. auricula residue to the field significantly increased the soil nutrient content. The contents of ammonium nitrogen, total nitrogen, total potassium, total phosphorus, available potassium (QK), available phosphorus, and organic matter in the F2 treatment increased by 180.49%, 70.41%, 16.3%, 54.35%, 137.33%, 38.84%, and 59.29%, respectively, compared to those of the K0 treatment. The activities of the soil enzymes urease, sucrase, β-glucosidase (β-GC), and acetyl-β-d-glucosidase significantly increased by 32.98%, 407.78%, 206.85%, and 186.26%, respectively, in the F2 treatment compared to those of K0; catalase and leucine aminopeptidase activities were increased by 244.42% and 130.90% in the F1 treatment compared to those of K0. Moreover, A. auricula residue return to the field increased the Chao1 and Shannon indices of the bacterial community, but decreased the diversity of the fungal community. Redundancy analysis showed that QK, β-GC, and urease were the main factors driving the changes in microbial communities. In conclusion, returning A. auricula mushroom residue to the field can enhance soil ecological functions by improving soil nutrients, enzyme activities, and microbial community structure.