Integrating composite microorganism agents in rice-crayfish rotational cropping systems to enhance water quality and productivity

Abstract

Global agriculture urgently needs sustainable strategies to balance rising food demands with environmental constraints. Although rice-crayfish rotation cropping makes efficient use of land and water, poor straw decomposition and impaired water quality often limit yields. Conventional solutions that rely on chemical inputs or frequent water exchanges can be expensive and pose environmental risks, highlighting an urgent need for eco-friendly alternatives. To address these challenges, this study developed an innovative rice-crayfish rotational cropping system that integrates rice cultivation with crayfish breeding, using multifunctional microbial inoculants to enhance sustainability and productivity. Field experiments showed that inoculating the lignocellulose-decomposing fungus Talaromyces funiculosus XM21 significantly accelerated straw degradation and enriched soil nutrients. During the crayfish breeding phase, combined microbial applications (functional SynCom & decomposer) improved water quality by reducing ammonia and nitrite levels and increasing dissolved oxygen content, leading to enhanced crayfish growth. These improvements, along with the application of beneficial microbes, increased rice yield and quality during the cultivation phase. Overall, the rice-crayfish system resulted in a 45.6 % increase in crayfish yields and a 26.4 % increase in rice yields, translating to a 77.2 % rise in income per hectare. This study highlights the potential of bioengineering strategies with beneficial microbial communities to enhance the sustainability and productivity of rice-crayfish systems, providing a pathway for modern agriculture amid environmental challenges.