Effects of Returning Mushroom Residues to the Field on Soil Properties and Rice Growth at Different Stages

Straw returning has been evidenced to be an effective strategy for straw utilization. Nevertheless, numerous adverse effects on straw direct returning have been widely reported. It is safer to fully degrade the straw and then return it to the soil. This strategy has been shown to significantly improve soil nutrients. However, the effect on rice growth is unclear. In this study, a pot experiment was conducted by using different types of mushroom residues with chemical fertilizer for field return, compared to the conventional method of applying chemical fertilizer alone, and straw return with or without fertilizer. It was found that the return of mushroom residues to the field could increases the soil organic matter content by 16.9–23.5%, the alkaline nitrogen by 39.1–47.4%, and the available potassium by 6.8–10.8%. Furthermore, mushroom residues were found to reduce the population of fungi and bacteria in the soil to a certain extent and increase the number of actinomycetes. Moreover, it was determined that mushroom residues elevated the nutrient content in plants, accelerated the tillering rate, and increased the number of tillers. This ultimately led to an increase in rice yield components, such as thousand-grain weight and the effective number of spikes. Mushroom residues can mimic the benefits of straw return while minimizing potential harm to rice yields. This study provides an effective strategy for the resource utilization of straw.