【目的】长期不合理施化肥对生态环境的影响已经引起学者和公众的关注,有机肥的施用越来越受到重视。揭示有机肥对农田杂草群落影响的机制、预测有机农业环境下杂草群落的演替趋势十分困难。本文对比研究不同施肥模式下农田杂草的群落特征,探索晚稻田杂草群落结构演变趋势,以期为现代农业中有机肥的合理施用和农田生物多样性保护提供科学依据。【方法】通过田间长期定位施肥试验,运用群落生态学方法研究了晚稻种植季五种施肥处理区杂草群落的结构特征及其生物多样性。在每个小区随机设置5个面积为0.25 m2的样方,记录各样方内杂草物种种类、每个种类杂草的数量,调查杂草的盖度与频度;测定稻谷理论产量;使用照度计测量地表与水稻冠层顶部的光照强度,计算光照透过率;测定耕作层土壤的有机质、碱解氮、有效磷、速效钾含量。计算杂草的重要值,采用物种丰富度(S)和Shannon-Wiener指数(H)测定杂草群落的生物多样性;以15个处理小区中的11种常见杂草的重要值构成原始数据矩阵,应用SPSS16.0软件进行主成分分析和典范对应分析。【结果】晚稻田不同施肥处理土壤养分以及光照透过率差异显著,施有机肥的处理晚稻稻谷产量高于CK与NPK纯化肥处理。CK处理区优势种为野荸荠-节节菜-异型莎草-鸭舌草,NPK处理区优势种为双穗雀稗,NPK5/5和NPK3/7处理区优势种为双穗雀稗-鸭舌草,NPK7/3处理区优势种为双穗雀稗-鸭舌草-稗。主成分分析结果表明15个施肥处理小区的杂草群落可以分为三大类:第一类是CK处理;第二类是NPK3/7处理;第三类是NPK、NPK5/5、NPK7/3三个处理。主成分Factor 1与有机质、碱解氮以及有效磷呈极显著负相关(P<0.01),与光照透过率呈极显著正相关(P<0.01)。典范对应分析结果显示,节节菜、野荸荠与牛毛毡比较适宜生长在CK处理区,双穗雀稗适宜在NPK7/3处理区生长,鸭舌草、陌上菜以及四叶萍适宜生长在NPK3/7处理区。有机肥处理区的物种丰富度与物种多样性指数处于NPK与CK之间,且随着有机肥比例的增加物种数增加。物种丰富度以及物种多样性指数与有机质、碱解氮以及有效磷呈极显著正的“U型”相关(P<0.01),与速效钾呈显著负相关(P<0.05),与群落光照条件呈极显著正相关(P<0.01)。【结论】晚稻田杂草群落特征与土壤有机质、碱解氮、有效磷含量以及地表光照透过率关系密切。均衡施用有机和无机肥可以显著降低杂草群落的优势种数量,将杂草群落的优势种数量以及生物多样性维持在不施肥与纯施化肥处理区之间。因此,可以通过调整有机肥的施用量来调控农田杂草生长及群落特性,实现农田杂草的科学综合管理。综合考虑晚稻稻谷产量和杂草群落生物多样性状况,NPK3/7(化肥30%+有机肥70%)施肥模式既可以保证作物的优质高产,也可以较好地维持杂草群落的生物多样性。 【Objective】 The long-term irrational application of fertilizers on the ecological environment has drawn the attention of scholars and the general public. The application of organic fertilizers has attracted more and more attention. It is very difficult to predict the succession of organic fertilizer on the weed community in farmland. In this paper, we compared the community characteristics of weeds in different fertilization modes and explored the evolution trend of weed community structure in late rice so as to provide a scientific basis for the rational application of organic fertilizers and the conservation of farmland biodiversity in modern agriculture. 【Method】 Based on the long-term fertilization experiment in the field, the community characteristics and biodiversity of five weed communities in five fertilization treatments were studied by using community ecology. Five plots of 0.25 m2 area were randomly allocated in each plot. The types of weeds, the number of weeds in each plot, the coverage and frequency of weeds were recorded; the theoretical yield of rice was measured; The light intensity of the top of rice canopy was measured by illuminometer and the light transmittance was calculated. The contents of organic matter, available nitrogen, available phosphorus and available potassium were determined. The importance of weeds was calculated, and the weed community diversity was determined by species richness (S) and Shannon-Wiener index (H). The importance values ​​of 11 common weeds in 15 treated plots formed the original data matrix , Using SPSS16.0 software for principal component analysis and canonical correspondence analysis. 【Result】 The results showed that there was significant difference in soil nutrient and light transmittance of different fertilization treatments in late rice paddy. The yield of paddy rice treated with organic manure was higher than CK and NPK pure fertilizers. The dominant species in CK treatment area were wild water chestnut - Roketai - Shaped sedge - Monochamus alternatus, the dominant species was B. paspalum in NPK treatment area, and the dominant species was B. paspalum - duck in NPK5 / 5 and NPK3 / 7 treatment areas The dominant species of tongue grass and NPK7 / 3 was Paspalum, Monochamus alterniflora and barnyardgrass. The results of principal component analysis showed that the weed communities in 15 fertilization plots could be divided into three groups: the first type was CK; the second type was NPK3 / 7; the third type was NPK, NPK5 / 5 and NPK7 / 3 Three processing. The principal component, Factor 1, showed a significantly negative correlation (P <0.01) with organic matter, available nitrogen, and available phosphorus, and had a significant positive correlation with light transmittance (P <0.01). The results of canonical correspondence analysis showed that Artemisia selengensis, Water chestnut and cow felts were more suitable for growth in CK treatment area, Paspalum bivalvia was suitable for growing in NPK7 / 3 treatment area, Monochamus alternatus, NPK3 / 7 treatment area. The species richness and species diversity index of organic fertilizer treatment area are between NPK and CK, and the number of species increases with the proportion of organic fertilizer. Species richness and species diversity index were significantly positively correlated with organic matter, available nitrogen, and available phosphorus (P <0.01), negatively correlated with available K (P <0.05) Light conditions were significantly and positively correlated (P <0.01). 【Conclusion】 The characteristics of weed community in late rice were closely related to soil organic matter, available nitrogen, available phosphorus, and surface light transmittance. The balanced application of organic and inorganic fertilizers can significantly reduce the number of dominant species in the weed community, maintaining the dominant species quantity and biodiversity of the weed community between no-fertilization and pure-fertilizer treatments. Therefore, by adjusting the amount of organic manure applied to regulate the growth of weeds and community characteristics of farmland to achieve the scientific integrated management of farmland weeds. Considering the status of paddy yield and weed community biodiversity in late rice, NPK3 / 7 (30% of chemical fertilizer and 70% of organic fertilizer) could not only ensure the high yield of crops, but also maintain the biodiversity of weed communities .