We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five ...We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five treatments and 4 replicates was set up in Qingzhou, Shandong Province, China. In addition to methyl bromide （MB） and untreated control （CK）, three alternative fumigation treatments were studied, including MB＋VIF （virtually impermeable films）, metham sodium （MS） and MS＋VIF. Tomato cultivars （Lyeopersicum eseulentum Mill）, cv. Maofen-802 were selected as test crops. Results of four fumigations were demonstrated through three-level ten-fold dilution methodology. Abundance of three groups of soil protozoa-flagellates, amoebae, and ciliates was measured from July 2002 to July 2003. Results indicated that two chemical fumigants and their combinations with physical material all significantly repressed soil protozoan abundance. MB was a stronger fumigant than MS, and use of VIF increased their repressive power. The most serious population reduction occurred in amoebae, thus, they also required the longest time to recover. MB and MS also changed the protozoan community structure. MB use decreased the percentage of amoebae but increased percentage of ciliates, while MS incrcased the percentagc of amoebae and decreased the percentage of flagellates in the protozoan community.展开更多
[目的]通过田间药效试验明确35%威百亩水剂对人参田杂草的防除效果和安全性,为威百亩在人参上的登记使用提供理论依据。[方法]通过2年2地田间试验,测定35%威百亩水剂不同施药剂量下进行土壤熏蒸对人参的安全性和除草效果。[结果]35%威...[目的]通过田间药效试验明确35%威百亩水剂对人参田杂草的防除效果和安全性,为威百亩在人参上的登记使用提供理论依据。[方法]通过2年2地田间试验,测定35%威百亩水剂不同施药剂量下进行土壤熏蒸对人参的安全性和除草效果。[结果]35%威百亩水剂在制剂用药量30、60、90 m L/m^2时,对一年生杂草鸭趾草、小飞蓬、藜、稗草、蓼株平均总体防效为73.48%～90.09%,鲜重总体防效为76.12%～95.57%,在试验剂量下未观察到药害发生。[结论]35%威百亩水剂在试验剂量下对人参生长安全,能够有效防除人参田杂草,可以用于人参田苗床杂草的防除。展开更多
研究了连作栽培条件下,威百亩土壤熏蒸与微生物菌剂联用对兰州百合(Lilium davidii var. unicolor)生长及土壤生物理化性状的影响。结果表明:与对照相比,威百亩熏蒸处理对百合生长有抑制作用,显著降低了百合产量。微生物菌剂处理对百合...研究了连作栽培条件下,威百亩土壤熏蒸与微生物菌剂联用对兰州百合(Lilium davidii var. unicolor)生长及土壤生物理化性状的影响。结果表明:与对照相比,威百亩熏蒸处理对百合生长有抑制作用,显著降低了百合产量。微生物菌剂处理对百合生长有促进作用,显著提高了百合产量;部分土壤生物化学指标发生了显著变化,与对照相比,土壤真菌数量下降,细菌数量增加;土壤总孔隙度和绝对含水量增加;土壤碱解氮、速效钾、速效磷等可利用养分含量增加,pH下降。而威百亩熏蒸与微生物菌剂联用处理与对照相比,作用效果不显著,但与单纯熏蒸处理相比,植株生长指标、土壤细菌数量及土壤理化性状指标有一定改善。在西北寒旱生态区山地蔬菜春茬旱作栽培模式下,受低温及土壤含水量不足的影响,威百亩熏蒸容易对百合产生药害;土壤熏蒸和微生物菌剂联用不能缓解兰州百合连作障碍;而单独使用微生物菌剂处理可以缓解连作障碍,并且可以消减威百亩处理所产生的负作用。利用异硫氰酸甲酯及其产生前体棉隆及威百亩进行土壤熏蒸,由于异硫氰酸甲酯有可能降解或挥发不完全,易发生药害,应慎重使用。展开更多
文摘We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five treatments and 4 replicates was set up in Qingzhou, Shandong Province, China. In addition to methyl bromide （MB） and untreated control （CK）, three alternative fumigation treatments were studied, including MB＋VIF （virtually impermeable films）, metham sodium （MS） and MS＋VIF. Tomato cultivars （Lyeopersicum eseulentum Mill）, cv. Maofen-802 were selected as test crops. Results of four fumigations were demonstrated through three-level ten-fold dilution methodology. Abundance of three groups of soil protozoa-flagellates, amoebae, and ciliates was measured from July 2002 to July 2003. Results indicated that two chemical fumigants and their combinations with physical material all significantly repressed soil protozoan abundance. MB was a stronger fumigant than MS, and use of VIF increased their repressive power. The most serious population reduction occurred in amoebae, thus, they also required the longest time to recover. MB and MS also changed the protozoan community structure. MB use decreased the percentage of amoebae but increased percentage of ciliates, while MS incrcased the percentagc of amoebae and decreased the percentage of flagellates in the protozoan community.
文摘[目的]通过田间药效试验明确35%威百亩水剂对人参田杂草的防除效果和安全性,为威百亩在人参上的登记使用提供理论依据。[方法]通过2年2地田间试验,测定35%威百亩水剂不同施药剂量下进行土壤熏蒸对人参的安全性和除草效果。[结果]35%威百亩水剂在制剂用药量30、60、90 m L/m^2时,对一年生杂草鸭趾草、小飞蓬、藜、稗草、蓼株平均总体防效为73.48%～90.09%,鲜重总体防效为76.12%～95.57%,在试验剂量下未观察到药害发生。[结论]35%威百亩水剂在试验剂量下对人参生长安全,能够有效防除人参田杂草,可以用于人参田苗床杂草的防除。
文摘研究了连作栽培条件下,威百亩土壤熏蒸与微生物菌剂联用对兰州百合(Lilium davidii var. unicolor)生长及土壤生物理化性状的影响。结果表明:与对照相比,威百亩熏蒸处理对百合生长有抑制作用,显著降低了百合产量。微生物菌剂处理对百合生长有促进作用,显著提高了百合产量;部分土壤生物化学指标发生了显著变化,与对照相比,土壤真菌数量下降,细菌数量增加;土壤总孔隙度和绝对含水量增加;土壤碱解氮、速效钾、速效磷等可利用养分含量增加,pH下降。而威百亩熏蒸与微生物菌剂联用处理与对照相比,作用效果不显著,但与单纯熏蒸处理相比,植株生长指标、土壤细菌数量及土壤理化性状指标有一定改善。在西北寒旱生态区山地蔬菜春茬旱作栽培模式下,受低温及土壤含水量不足的影响,威百亩熏蒸容易对百合产生药害;土壤熏蒸和微生物菌剂联用不能缓解兰州百合连作障碍;而单独使用微生物菌剂处理可以缓解连作障碍,并且可以消减威百亩处理所产生的负作用。利用异硫氰酸甲酯及其产生前体棉隆及威百亩进行土壤熏蒸,由于异硫氰酸甲酯有可能降解或挥发不完全,易发生药害,应慎重使用。
