微生物菌剂与耕作方式对冬小麦土壤化学性状的影响

Effects of Different Microbial Inoculants and Tillage Types on the Soil Chemical Properties of Winter Wheat

为了解不同的耕作方式和微生物菌剂施用下土壤化学性状的动态变化特征,在玉米秸秆还田的基础上,于冬小麦季通过田间小区试验,研究了旋耕和深耕2种耕作方式以及添加不同外源微生物菌剂条件下,冬小麦不同生育期土壤速效磷、速效钾、土壤微生物量碳氮的动态变化特征。结果表明,2种耕作方式下对土壤速效磷、速效钾、微生物量碳氮含量差异不显著,但小麦季不同生育期对这些的影响达到显著水平。旋耕方式下,施用(沼液+根际促生菌)和EM菌分别对土壤速效磷、土壤速效钾效果最明显;深耕方式下,施用(沼液+根际促生菌)和沼液分别对土壤速效磷、土壤速效钾效果最好;2种耕作方式下施用根际促生菌降低了土壤碳氮比值,有利于秸秆的腐解。土壤速效钾在小麦季收获期根区较非根区含量分别增加了44.31%(旋耕)和32.61%(深耕)。2种耕作方式下的根区土壤微生物量碳、氮显著高于非根区,且添加EM菌均能提高土壤微生物量碳、氮含量。

In order to understand the dynamics of soil chemical characteristics （soil available phosphorus, soil available potassium and soil microbial biomass carbon and nitrogen） of two types of tillage and different microbial inoculants during winter wheat growing periods, the author conducted plots experiment based on straw returning to field. The results showed that two the types of tillage had no significant effect on soil available phosphorus, available potassium, soil microbial biomass carbon and nitrogen content, but different growing stages showed significant impact on these indices. Application of biogas slurry ＋ plant growth- promoting rhizo-bacteria or EM influenced soil available phosphorus or soil available potassium in the rotary tillage markedly; while application of biogas slurry ＋ plant growth-promoting rhizo-bacteria or biogas slurry had best effect on soil available phosphorus or soil available potassium in the deep tillage. The addition of plant growth-promoting rhizo-bacteria under the two types of tillage could reduce soil carbon nitrogen ratio and enhance the decomposition of straw. The soil available potassium in the root zone increased by 44.31% （rotary tillage） and 32.61% （deep tillage microbial biomass carbon and nitrogen of tillage, and application of EM strain biomass nitrogen. ） comparing to that in the non-root zone at the wheat harvest stage. Soil in root zone was higher than that in non-root zone under the two types could improve the level of soil microbial biomass carbon and microbial