杀灭土壤中线虫对小麦生长和吸收N、P的影响

盆栽条件下研究了施用杀线剂(克线磷,67mg·kg^-1干土)和干热(105℃,2h)两种杀线措施对小麦生长和N、P养分吸收的影响。杀线剂对土壤中线虫的平均杀灭率约为80%, 干热处理的杀灭率为100%. 在杀线剂处理中,苗期至抽穗期小麦生物量、拔节期至成熟期植株含N量、全生育期植株吸N量以及抽穗和成熟期吸P量均显着低于对照。土壤干热处理后抽穗和成熟期小麦的生物量、含N量及N、P吸收量也比对照显着降低。两种杀线处理植株地上部生物量和N、P吸收量与相应处理全株变化趋势基本一致。但杀灭线虫对植株含P量影响较小。分析杀线虫后小麦生长和养分吸收受抑主要与土壤有机氮的矿化作用减弱、微生物活动产生的植物生长促进物质降低有关

Effect of soil nematode exclusion on wheat growth and its N and P uptake

The soil used for pot experiment was treated by a nematocide (phenamiphos, 67mg·kg^-1 dry soil) or dry heating at 105℃ for 2h before wheat (Triticum aestivum) planting to study the effect of these two treatments on wheat growth and its Nand Puptake.Approximately 80% of the nematodes in soil were eliminated by nematocide and 100% by dry heating.Significantly lower wheat biomass was found in nematocide treatment than in control from seedling to heading stage.The same was true for plant Ncontent from jointing to ripening stage, Nuptake in whole growing season, and Puptake from heading to ripening stage.In dry heating treatment, wheat biomass, Ncontent and Nand Puptake were also markedly lower than control from heading to ripening stage.The aboveground biomass and its Nand Puptake had a similar tendency with those of whole plant for the two treatments.However, nematode exclusion had little effect on plant Pcontent.The inhibitory effect of nematode exclusion on wheat growth and its nutrient uptake was suggested to be associated with the reduce of Nmineralization and of plant growth promoting substance derived from soil microbial activities.