滇池流域农田生态沟渠杂草氮磷富集效应的研究

通过研究滇池柴河流域不同时期农田近自然生态沟渠杂草对农田径流水及土壤有效氮磷的富集效应和测算杂草生物量及植株氮磷比值等，进行杂草去除氮、磷效果测算及物种去除氮、磷效果量化，以期为滇池水体富营养化的综合治理提供依据.结果表明：①同一物种或不同物种在不同时期，各杂草种间氮磷富集差异较大；②近自然杂草植株体对氮磷的富集主要表现为氮限制类型（N〖DK〗∶P<14）；③农田生态沟渠近自然杂草生物量与氮磷养分吸收呈正相关关系，全年流域氮、磷富集总量为（37.86±9.9） kg/hm2和（4.27±1.19） kg/hm2，远远小于滇池流域氮最大流失量113.16 kg/hm2和磷最大流失量10.14 kg/hm2.

Research on the effects of weed nitrogen and phosphorus enrichment in natural approximating ecological agro-ditches of Dianchi Lake basin

This paper quantified the weed and species removal effect of N&;P respectively, and definite the yearly absorption and removal effect of N&;P in farmland soil and runoff by weed in the natural approximating ecological agro-ditches in Dianchi Lake basin, to provide the evidence of water eutrophication comprehensive treatment in agro-diffused pollution by cutting N&;P effectively and source control. The result proved: ① There is a great difference of N&;P enrichment among different weeds, in the same or different species of different periods; ② the main phenomenon of N&;P enrichment of natural approximating weed plant is N limitation (N〖DK〗∶P<14); ③ there is positive relationship between N&;P nutrient absorption and the weed biomass in natural approximating ecological agro-ditch of farmland, and the whole year total amount of N&;P in the basin were N (37.86±9.9) kg/hm2, P (27±1.19) kg/ha, which were much lower than the maximum of N 113.16 kg/ha, P 10.14 kg/hm2.