中文摘要：

施肥等人为管理下农田生态系统生物多样性的变化规律及其保护是生态系统研究的重要内容之一。我们通过镜检法对太湖地区一个长期肥料定点试验稻油轮作田表层（0—15cm）土壤中杂草种子的种类进行了鉴定，分析了长期不同施肥方式对稻油轮作田土壤杂草种了库群落结构及多样性的影响，讨论了杂草种了片多样性与农田生态系统生产力和稳定性的关系。4种施肥方式分别为不施肥（NF）、单施化肥（CF）、化肥配施猪粪（CMF）以及化肥配施秸秆（CSF）。结果表明：无论水稻种植季还是油菜种植季，与长期不施肥、单施化肥及化肥配施猪粪相比，化肥配施秸秆条件下的田间土壤杂草种子库密度均最低，但其总物种数和多样性较高；同时，这种施肥方式下水稻与油菜的年平均产量也较高，而且年际波动小。可见，施肥方式的不同会影响杂草种了厍的多样性，而多样性的高低与农作物产量高低及稳定性有着一定的相关关系：即均衡的施肥方式有利于维持土壤杂草种子库多样性，提高农作物产量，并降低产量年际间的波动性。在本文研究的4种施肥方式中，化肥配施秸秆可以作为提高农田生态系统生产力和稳定性并保持生物多样性的农田施肥管理方式。

英文摘要：

To study the dynamics in crop-field soil biodiversity under long-term fertilization is important for agricultural ecosystem protection. We selected a long-term fertilized paddy field under rice/rape rotation from the Taihu Lake region as a study site, and identified weed seeds in the topsoil （0-15 cm） by microscopic examination. Weed seed number and crop yields were recorded. We analyzed the effect of long-term fertilization on soil weed seed bank diversity and the relationship between weed seed diversity and crop yields. The fertilizer treatments were as follows： non-fertilizer （NF）, chemical fertilizer only （CF）, chemical fertilizer and pig manure combined （CMF）, and chemical fertilizer plus crop stalk （CSF）. The results indicated that in the cultivating seasons of both rice and rape, under the treatment of chemical fertilizer plus rice crop stalk, the density of soil weed seed bank was the lowest, whereas the total species number and diversity was the highest. Furthermore, the crop yields were maximal and the steadiest under this treatment. There was definite correlation among fertilizer treatments, soil weed seed bank diversity and crop yields. It was concluded that balanced fertilizer management helps to maintain soil weed seed bank diversity, increase crop yields, and prevent crop yields from fluctuating. Therefore, among the four fertilizer treatments, chemical fertilizer plus rice crop stalk was the best one to increase the productivity of agricultural ecosystems and simultaneously protect biodiversity.