施用微生物有机肥对连作条件下西瓜的生物效应及土壤生物性状的影响

为探讨施用微生物有机肥对连作条件下西瓜生长、土壤微生物的影响,在西瓜连作3年的土壤上采用小区试验方法分析施用微生物有机肥对西瓜的生物学效应及对土壤微生物群落结构的影响。试验设置4个处理,依次为健康菜园土育苗(CK)、健康菜园土育苗+定植期增施微生物有机肥(施肥量为每株25 g)、健康菜园土+微生物有机肥育苗(微生物有机肥︰健康菜园土=1︰49)、健康菜园土+微生物有机肥育苗+定植期增施微生物有机肥(施肥量为每株25 g)。结果显示:在育苗及定植期均施用微生物有机肥使西瓜的生物学性状得到显著改善。与对照相比,施用微生物有机肥使西瓜株高、叶片数、叶绿素含量、植株氮、磷、钾吸收总量以及西瓜品质、产量显著增加(P<0.05);同时,微生物有机肥富含优质碳源和微生物,健康菜园土育苗+定植时增施微生物有机肥和健康菜园土+微生物有机肥育苗+定植期增施微生物有机肥处理土壤中细菌总量与对照相比分别增加24.9%~51.0%和35.7%~55.8%,放线菌数量分别增加18%~41%和15%~35%,真菌数量分别增加7.4%~21.9%和4.9%~31.9%;土壤中有益菌数量和放线菌与真菌的比例增加可有效抑制尖孢镰刀菌活性,对枯萎病的防治率高达83%以上。微生物有机肥能激发连作土壤有益微生物活性,显著改善和调节连作西瓜生长,对西瓜的连作障碍有明显缓解作用。

Effect of organic microbe fertilizer application on watermelon growth and soil microorganisms under continuous mono-cropping

Plot and field experiments were carried out to investigate the effect of organic microbe fertilizer(OMF) application on the bio-properties of watermelon and soil microorganisms under continuous mono-cropping.The field of the experiment was already continuously mono-cropped for three consecutive years with watermelon.Four treatments were arrayed — watermelon seedling was cultured in healthy vegetable garden soil(T1,control),T1 + application of 25 g per plant of OMF at transplanting period(T2),water-melon seedling was cultured in healthy vegetable garden soil with 2% OMF;T4: T3 + application of 25 g per plant of OMF at trans-planting period.Results showed that compared with the control,application of OMF significantly increased(P < 0.05) plant height,leaf number,chlorophyll content,total uptakes of N,P and K,and quality and yield of watermelon.After high-quality carbon and microbe OMF application,the numbers of bacteria of the treatments T2 and T4 increased by 24.9%～51.0% and 35.7～55.8%,actino-mycetes by 18%～41% and 15%～35% and fungi by 7.4%～21.9% and 4.9%～31.9%,respectively over the control.Conversely,the number of fusarium oxysporum(a witling disease causing fungi) significantly decreased.The number of actinomycetes,fungi was increased.The control rate of wilt was more than 83%.The results suggested that OMF application(especially at seedling and trans-planting stages) significantly promoted watermelon growth,stimulated soil microbial activity and limited the adverse effects of con-tinuously cropping on watermelon.