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利用盆栽试验,研究了不同年限连作对芝麻农艺性状、产量性状、土壤化学性状和微生物数量的影响。结果表明:与正茬相比,连作情况下芝麻的株高、果轴长度、单株蒴数、单蒴粒数、千粒重、单株产量均显著下降。连作1~3年,单株蒴数下降范围为8.41%~20.85%,单蒴粒数为7.32%~18.16%,千粒重为4.69%~14.72%,单株产量为11.86%~44.07%,并且连作年限越长,农艺性状变劣越严重。连作对芝麻根际土壤微生物活性影响较大,导致根际土壤微生物菌群改变,比例失调。随着连作年限增加,土壤中微生物总量下降,根区土壤中细菌、放线菌、真菌数量都有显著下降,连作3年,分别下降了66.1%、76.2%、56.0%;根际土壤中细菌、放线菌数量下降,而真菌数量增加。土壤速效氮、磷、钾,交换性钙、镁,有效锰、硼、铁、铜和锌随连作年限增加而下降,连作3年,土壤速效磷、钾,交换性钙,有效硼、铁和锌的养分递减率都达5%以上,连作还导致土壤供肥能力变差。
Pot experiments were conducted to study the effects of continuous cropping with different years on the agronomic characters, yield traits, soil chemical properties and microbial population of sesame. The results showed that plant height, length of axillary axis, number of bolls per plant, number of bolls per plant, grain weight per plant, grain weight per plant and yield per plant decreased significantly under continuous cropping. Continuous cropping 1-3 years, the number of bolls per plant decreased from 8.41% to 20.85%, boll number was 7.32% ~ 18.16%, grain weight was 4.69% ~ 14.72%, yield per plant was 11.86% ~ 44.07% The longer the duration, aggravating aggravating agronomic traits. Continuous cropping had a great influence on the microbial activity of rhizosphere soil in sesame, which led to the change of microbial flora in the rhizosphere and the imbalanced proportion. The amount of bacteria, actinomycetes and fungi in the root zone soil decreased significantly with the continuous cropping years increasing, and the total amount of soil microbes decreased significantly. The number of fungi decreased significantly by 66.1%, 76.2% and 56.0% respectively in the three years of continuous cropping. Bacteria, actinomycetes decreased, while the number of fungi increased. Soil available N, P, K, exchangeable Ca, Mg, available Mn, B, Fe, Cu and Zn decreased with continuous cropping years. Even for 3 years, available P, K, exchangeable Ca, available boron, Zinc nutrient decline rate of more than 5%, even cropping also lead to poor soil fertility.