Effect of added straw carbon on soil microbe and protozoa abundance
添加秸秆碳源对土壤微生物生物量和原生动物丰富度的影响

Driven by economic profits, the area of vegetables grown under plastic-film greenhouse has rapidly increased in recent years in China. Specific environmental conditions in plastic-film greenhouses could cause severe root-knot nematode disease. Hence a greenhouse pot experiment was conducted to study the effects of added straw carbon on soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and soil protozoa abundance. In the experiment, independent cultivation methods and selected tomato crops were used in a 3-gradient additive 1N (2.08 g·kg-1), 2N (4.16 g·kg-1) and 4N (8.32 g·kg-1)] of winter wheat straw. Two sets of experiments were set up with respective tomato growth durations of 6 and 4 months. Based on the study, the order of abundance of MBC, MBN and protozoa was 4N>2N>1N>CK. Wheat straw carbon significantly enhanced MBC, MBN and protozoa abundance and protozoa community structure. Flagellate and amoeba were in vast proportions of soil microbial abundance, respectively accounting for 29.44% and 66.19%. Ciliates accounted for only 4.37% of total soil microbial abundance. With increasing cultivation period, soil protozoa abundance increased while soil MBC and MBN decreased under the same additive amount of wheat straw carbon. Under the same cultivation period, MBC, MBN, MBC/MBN ratio and soil protozoa abundance increased with increasing amount of added wheat straw carbon.