稻田不同水分管理方式对土壤线虫群落的影响

在下辽河平原地区就稻田不同水分管理方式对土壤线虫多度、营养类群、群落组成的影响进行了研究．结果表明，0～10cm土层不同水分管理处理的线虫总数在耙耕前和黄熟期显著低于对照，10～20cm土层各时期处理间线虫总数的差异不显著，20～30cm土层线虫总数在耙耕前和黄熟期差异极显著．北方单季稻水田试验共观察到土壤线虫16科22属．绕线属(Plectus)、垫刃属(Tylenchus)、单宫属(Monhystera)是优势属，绕线属和垫刃属对不同的水分管理比较敏感．在耙耕前和黄熟期不同水分管理方式对0～10cm土壤食细菌线虫能够产生显著影响．稻田土壤中食细菌线虫和植物寄生线虫是优势营养类群，而捕食／杂食性线虫的相对多度最低．

Effects of water managements on soil nematode communities in a paddy field

This paper studied the effect of water managements on the abundance, trophic groups and community composition of soil nematodes in a paddy field in the Lower Reaches of Liaohe Plain at the depths of 0-10 cm, 10-20 cm and 20-30 cm during rice (Oryza sativa L.) growth season. The total number of nematodes at 0-10 cm soil depth was lower in percolation-controlling treatments than in control during pre-tillage and yellow ripeness stage. No significant difference was found in the total number of nematodes at 10-20 cm soil depth during the study period, but significant difference was observed in 20-30 cm soil depth during pre-tillage and yellow ripeness stage. Sixteen families and 22 genera were observed, and Plectus, Tylenchus and Monhystera were the dominant genera. Plectus and Tylenchus were sensitive to different water managements. Significant difference was found in the number of bacterivores at 0-10 cm soil depth during pre-tillage and yellow ripeness stage in percolation-controlling treatments, which exhibited a similar trend with the total number of nematodes. Bacterivores and plant-parasites were the most abundant trophic groups in all plots and at all soil depths during the study period, averaging 60.8% and 33.8% of the nematode communities, respectively, and omnivores-predators were the least abundant groups.