西瓜连作土壤微生态环境对生物耕作的动态响应

Dynamic response of soil microecological environment to earthworm tillage in watermelon continuous cropping

采用盆栽试验,考察生物耕作(接种蚯蚓)在不同时间尺度上对西瓜连作土壤理化性质、微生物群落特征的影响。结果表明:生物耕作90 d,土壤p H趋近中性,为7.25—7.68;速效氮、速效磷、速效钾较对照组分别提高了13.51%—36.68%、26.45%—46.33%、8.74%—22.29%;粒径> 0.25 mm的土壤大团聚体的比重提升了2.88%—29.10%;随生物耕作时间延长,土壤Cu、Zn、 Mn、Fe的含量无显著变化,而Ca的含量呈上升趋势,Mg含量则呈下降趋势;生物耕作组细菌数和放线菌较对照组分别提升54.95%—107.69%和15.81%—27.49%,而真菌则下降了28.67%—52.68%。综上,生物耕作能有效改善西瓜连作土壤的理化性质,促进土壤养分转化,提升土壤微生物总量,提高细菌和真菌比,促进土壤微生态环境的改善;提高生物耕作的密度有助于提高土壤微生态环境的改善速度,缩短处理时间;在质量相近的情况下,威廉环毛蚓对土壤的修复效果优于赤子爱胜蚓。

The greenhouse pot experiments were conducted to investigate different earthworm tillages on soil physi-chemical properties and microorganisms communities structure at different time scales.The data showed that after 90 days of earthworm tillage,the soil pH was 7.25—7.68,and the available nitrogen,available phosphorus and available potassium were increased by 13.51%—36.68%,26.45%—46.33%,8.74%—22.29%,respectively.The proportion of soil aggregates with particle size>0.25 mm increased by 2.88%—29.10%.The contents of Cu,Zn,Mn and Fe in soil showed no significant changes,but the content of Ca increased with the extension of earthworm tillage time,while the content of Mg decreased.The number of bacteria and actinomycetes of the earthworm tillage group increased by 54.95%—107.69%and 15.81%—27.49%respectively,while fungi decreased by 28.67%—52.68%.The results showed that earthworm tillage could effectively improve the physi-chemical properties of watermelon continuous cropping soil,promote the transformation of soil nutrients,increase the total amount of soil microorganisms,increase the ratio of bacteria to fungi,and promote the improvement of soil micro-ecological environment.Increasing the density of earthworms was helpful to speed up the improvement of soil micro-ecological environment and shorten the treatment times.In the case of similar weight,the effect of soil remediation by Metaphire guillelmi was better than that of Eisenia foetida.