Fungal Community in Soil Affected by Long-term Returning Maize Stover to Field

  Objective   Effects of different ways to return maize stover onto field after harvest on the nutrients and fungal community in soil were investigated.

  Method   A randomized group experiment was conducted in the maize producing areas in western Heilongjiang from 2015 to 2021 on Nendan 19 . The applied treatments included (1) no straw return (CK), (2) mulching ground with stover (CSR), (3) mixing chopped straws with soil (MSR), (4) deep plowing spent straws into soil (PSR), and (5) rotational return of stover (RSR). The effects on the soil and environmental drivers of fungal community were monitored by the Illumina Miseq sequencing technology.

  Result  Time, method, and their interaction of the treatments exerted significant or extremely significant effects on the diversity and structure of the fungal community as well as the soil chemistry. The dominant fungal phyla in soil at the maize jointing stage were Basidiomycota, Ascomycota, and Mortierellomycota, while the dominant genera were Tausonia, Coprinellus, and Solicoccozyma. Whereas, at the silking stage, the dominant phyla were Ascomycota and Mortierellomycota. The RDA analysis showed that nitrate, fast-acting phosphorus, and ammonium nitrogen were the key environmental factors that altered the fungal community at genera level. Compared to CK, the maize yield under RSR increased by 3.92%, under MSR by 3.76%, and under PSR by 1.97%.

  Conclusions  Under RSR the maize yield increased 3.92% over CK with an improved fungal richness index at jointing stage and a higher ASV than other treatments. At the same time, the abundant Penicillium spp. in soil due to the treatment materially hastened the lignocellulose degradation as the plant material decayed. RSR was, thus, the recommended utilization of the farm waste for maize cultivation in the region.