Fang Li;Chen Lin;Yue Li;Yong Han;Yi Wang;Shuiqing Zhang;Jiabao Zhan

Co-construction State Key Laboratory of Wheat and Maize Crop Science, College of Resources and Environment, Henan Agricultural University Zhengzhou 450044 (China); College of Resources and Environment, Henan Agricultural University, Zhengzhou 450044 (China);State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China;State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China);College of Resources and Environment, Henan Agricultural University, Zhengzhou 450044 (China);Institute of Plant Nutrition and Environmental Resources Science, Henan Academy of Agricultural Sciences, Zhengzhou 450002 (China)

uniseriatum;fallowing;fertilization;treatments;chaetomiaceae;melanogenesi

Cropland expansion has caused the loss of soil organic carbon (SOC) and the degradation of microbial communities. Fallowing is an important strategy for soil restoration, and fungi are critical in soil fertilization. This study compared the soil properties and fungal assemblage in two adjacent environments (farmland vs. fallowing) using a 30-year field experiment composed of five treatments: fallowing or agricultural management plus no fertilization, chemical fertilization, and chemical fertilization plus cow manure or crop straw amendments. The fallowed soil had more diverse fungi and maintained a higher SOC than the artificially managed treatments. Importantly, the relative abundance of Chaetomiaceae was positively correlated with all the carbon components (SOC, dissolved organic carbon, and microbial biomass carbon) simultaneously. An RNA-Seq of Trichocladium uniseriatum, the key fungus affiliated with Chaetomiaceae, showed that straw amendment significantly upregulated the genes for T. uniseriatum melanogenesis, resulting in recalcitrant necromass formation. A remarkable CO2 assimilation capacity of T. uniseriatum was revealed by 13C-labelling assay. Therefore, T. uniseriatum improved SOC storage directly by CO2 fixation and indirectly by melanogenesis. Fertilization of agricultural systems can stimulate the growth of T. uniseriatum. T. uniseriatum inoculation promoted crop growth, facilitating C absorption from the roots. This study highlighted that the valuable microbial species resources preserved in fallowed soils can improve farmland ecosystems.