Effects of Microbial Agents on Phytoplankton Community Structure and Water Quality in Paddy Fields with Red Swamp Crayfish Procambarus clarkii
To assess the impact of microbial agents on water quality in paddy fields with Procambarus clarkii,three different treatments were implemented at the Agricultural Science and Technology Park of Yangtze University in Jingzhou City,Hubei Province(30°22'12"N,112° 4'12"E).The treatments included the application of Bacillus subtilis(YB),photosynthetic bacteria(GH)and no microbial agents'application(CK).Each treatment covered an area of 1 100 m2,divided into four repeated smaller fields using impermeable enclosure.The experiments were conducted from March to May in 2019,encompassing the larval,adult,and mature stages of P.clarkii.The study was aimed to investigate the effects of microbial application on the community structure of phytoplankton in paddy field water,along with the associated environmental factors.The results revealed the presence of 106 phytoplankton species from 8 phyla across the three treatments.Among them,85,82 and 80 species were identified in the YB,CK,and GH treatments,respectively.The main dominant species included Schroederia nitzschioides,Pseudanabaena sp.,Merismopedia tenuissima and Chroomonas caudata.The total phytoplankton abundance and biomass in the three treatments were ranged from 3.10× 106 cells·L-1 to 20.45× 106cells·L1 and 1.40 mg·L-1 to 8.22 mg·L-1,respectively.Chlorophyta,Cyanobacteria and Cryptophyta were the predominant phyla in all treatments.During the juvenile and adult stages,both phytoplankton abundance and biomass followed the order YB＞GH＞CK,while in the mature stage,the order was CK＞YB＞GH.The Margalef,Pielou and Shannon-Wiener indices indicated higher diversity in the YB and GH treatments compared to the CK treatment.Based on these diversity indices,the water quality in paddy fields ranged from lightly to moderately polluted.Multiple linear regression analysis revealed that water temperature,dissolved oxygen and nutrients were significant environmental factors influencing the structure of phytoplankton communities in the paddy fields ofP.clarkii.Overall,the findings suggest that the application of microbial agents in paddy fields had minimal effects on phytoplankton growth,water quality improvement and phytoplankton community structure stability.
NETL
NSTL
万方数据
