不同水分模式分次施氮对水稻根际土壤微生物生态效应的影响

    研究了3种水分模式(干旱交替型,浅水层连续灌溉型和控水模式)及分次施氮条件下,施氮对水稻根际土壤微生物生态效应的影响,结果表明:水稻根际土壤微生物生态效应,不仅仅受到水分条件和施氮的影响,还受到水分条件和施氮的交叉影响.氮素因子一般在水稻生长的分蘖期就对水稻根际土壤微生物生态效应有显著影响,到孕穗期,水分条件开始起作用,在成熟后期,水稻不仅受到水分条件和施氮的影响,同时还受到水分条件和施氮的交叉作用影响.这说明在分次施氮的施肥模式下,施氮对水稻根际土壤微生物的生态效应保持一定的持续作用,而水分条件对土壤微生物的生态效应也需要一定的时间才能起作用.同时在水稻生长周期内的各个时期,水稻根际土壤微生物生物量碳与根际土壤酶等变化并不完全一致.

Ecological effect of rice rhizosphere microbes under water regimes and nitrogen fertilizer with split application in paddy field

Study on the ecological effect of rice rhizosphere microbes under three water regimes and two nitrogen application levels was conducted in 2005 in pot experiment. The research results indicated that the ecological effect of rice rhizosphere microbes was not only affected by water regime and nitrogen fertilizer separately, but also affected by the mutual effect of the two factors. In general, N had a dramatic effect in the tillering stage, water regime produced little in the booting stage, during the rice riping stage, the rice was not only affected by water condition and N, but also affected by mutual influence. It was indicated N split supply has an accumulated ecological effect on the rice rhizosphere microbes activities, so does water factor on the soil microbes of rice rhizosphere. During the rice growth stages, the microbial biomass C content in rice rhizosphere didn't vary from the changes of enzymes in the soil.