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分别于2011年5月、7月和9月,通过设置免耕农田不同的玉米秸秆覆盖率,调查了中小型土壤动物的生态分布特征。采用Tullgren法分离中小型土壤动物,室内显微镜下鉴定。结果表明:共获得中小型土壤动物6 814只。其中优势类群:甲螨(Oribatida)和辐螨(Actinedida),占总个体数的77.71%。土壤动物集中分布在0—10cm土层,占总个体数的76%,表聚性明显。Margalef物种丰富度指数(R)指数显示,R(全秸秆覆盖+免耕)3.10>R(50%秸秆覆盖+免耕)2.96>R(普通玉米田)2.18,说明全玉米秸秆覆盖免耕的农田中小型土壤动物类群多样性最高,个体数量最多。50%秸秆覆盖和全秸秆覆盖处理下中小型土壤动物的丰富度均高于普通玉米田。全秸秆覆盖免耕条件下螨类的数量是2 680只,是普通玉米田螨类数量的1.32倍。在50%秸秆覆盖+免耕、全秸秆覆盖+免耕和普通玉米田这3种不同秸秆覆盖率和土壤环境下,中小型土壤动物的季节分布差异明显。全秸秆覆盖与普通玉米田相比,能提供更丰富的生存条件,有效提高了中小型土壤动物的生物多样性。
In May, July and September 2011, the ecological distribution characteristics of small and medium-sized soil animals were investigated by setting different corn stalk coverage rates in no-till fields. Small and medium soil fauna were isolated by Tullgren method and identified under laboratory microscope. The results showed that a total of 6 814 small and medium sized soil animals were obtained. Among them, the dominant species were Oribatida and Actinedida, accounting for 77.71% of the total number of individuals. Soil animals concentrated in the 0-10cm soil layer, accounting for 76% of the total number of individuals, the apparent polygamy. Margalef species richness index (R) showed that R (whole straw mulch + no tillage) 3.10> R (50% mulching + no tillage) 2.96> R (common corn) Small and medium-sized soil fauna in farmland has the highest diversity and highest number of individuals. The richness of small and medium sized soil animal under 50% straw mulching and the whole straw mulching was higher than that of the common corn field. The total number of mites under no-till conditions in the whole straw mulch was 2 680, which was 1.32 times of the number of mites in common corn fields. There were significant differences in the seasonal distribution of small and medium sized soil animals under the conditions of 50% straw mulching + no-tillage, full straw mulching + no-tillage and ordinary corn fields. Compared with the common corn field, the whole straw mulch provides more abundant living conditions and effectively improves the biodiversity of small and medium sized soil animals.