Mechanistic insights into phosphorus transformation mediated by Arthrobacter and Sordariomycetes under longterm high-volume swine manure application in a wheat-rice rotation system

Chunlong Zhang¹Shuang Zhang²Xiaoyan Tang²Bin Bin Zhang¹Dejun Liu¹Zepeng Yang³Rong Huang²Yingjie Wu²Qi Tao²Youlin Luo²Changquan Wang²Li Bing^2*

• ¹School of Pharmacy and Medical Laboratory Science, Ya’an Polytechnic College, Ya’an, China, Ya’an, China
• ²College of Resource, Sichuan Agricultural University, Chengdu, China
• ³Institute of Agricultural Resource and Environment, Sichuan Academy of Agricultural Sciences, Chengdu, China

Introduction: Understanding the impacts of sustained high-input swine manure on soil phosphorus (P), along with identifying and functionally characterizing P-associated microorganisms, can provide a scientific foundation for effective management of soil P in relation to swine manure application.The study investigated the prolonged impact of high-volume swine manure application on soil P fractions over an 8-year continuous, randomized field trial involving rotating wheat (wet conditions) and rice (flooded conditions) crops. And the soil treated with the prolonged highvolume swine manure application was selected to isolate and identify specific microorganisms, which were subsequently inoculated into soil previously treated with long-term NPK fertilizer (F) and swine manure application (M) for indoor cultivation and functional characterization verification.The sustained high input of swine manure markedly enhanced soil P activity and microbial P content (P<0.05), specifically extracting P-associated microorganisms, namely Arthrobacter sp. M4 bacteria and Sordariomycetes 2 MS-M4 fungi. Upon separate inoculation of these microorganisms into high-Carbon (C) and high-P soils (Olsen P > 70 mg kg -1 , ROC > 150 mg kg -1 ), it was observed that both microorganisms effectively converted available P sources into organic P reserves through biological immobilization. Conversely, under conditions of low C and low P (Olsen P < 10 mg kg -1 , ROC < 75 mg kg -1 ), there was an enhancement in the decomposition and utilization of soil organic C which resulted in increased effective P content via the breakdown of organic phosphates-demonstrating a robust capacity for P transformation. Furthermore, when these phosphate-related microorganisms were introduced to long-term fertilized soils enriched with NPK fertilizer (F), they exhibited a significantly greater enhancement in soil P availability compared to those inoculated into soils subjected to prolonged high inputs of swine manure.The P-related microorganisms Arthrobacter sp.M4 and Sordariomycetes 2 MS-M4 extracted from soils with high P availability were confirmed to have the key functions of enhancing the fixation of inorganic P into organic P (high-C and high-P condition) or promoting the activation of organic P into rapidly available P (low C and low P level). Which may plays an important role in the management of agricultural P nutrients.