摘要
【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。
【Objectives】Effect of long-term and unreasonable chemical fertilization on ecological environment has attracted attention of scholars and the public,and application of organic fertilizer is paid more and more attention.It is difficult to reveal mechanism of organic fertilization on weed communities and forecast evolution trend of weed communities under organic farming environment. This paper was to study weed communities under different fertilization patterns in farmlands,and explore evolution trend of weed community structure in late rice fields.【Methods】The weed community structure features and biodiversity of five fertilization treatments in late rice growing season were studied by using the method of community ecology based on a long-term fertilization field experiment. Five quadrats each with 0. 25 m2 area were set in each plot for sampling and investigation,and weed species,numbers,coverage and frequency in the quadrats were recorded and the rice yields were measured. Digital light meters were placed on the soil surface and top of the crop canopy. Soil samples were taken in each plot to analyze organic matter,available N,P and K. The importance values of each weed species in each plot were calculated,and the biodiversity of weeds was measured with the species richness S and Shannon-Wiener index H.Importance values of 11 common weed species in 15 plots were used as original matrix for principal components analysis and canonical correspondence analysis( CCA) by SPSS16. 0. 【Results】There are significant differences of soil nutrients and light transmittance in late rice fields under the different fertilization patterns. The rice yields in the treatments of combined application of organic manure and chemical fertilizers are higher than those in other treatments. Heleocharis plantagineiformis,Rotala indica,Cyperus difformis and Monochoria vaginalis are dominant weed species in the CK treatment. Paspalum paspaloides is dominant weed species in the NPK treatment. The weed species in the NPK5 /5 and NPK3 /7 treatments are dominated by Paspalum paspaloides and Cyperus difformis.Paspalum paspaloides,Cyperus difformis and Echinochloa crusgalli are dominant weed species in the NPK7 /3treatment. The result of PCA indicates that the 15 weed communities can be divided into three patterns: pattern 1includes the CK treatment,pattern 2 includes the NPK3 /7 fertilization treatment,and pattern 3 includes the NPK,NPK5 /5 and NPK7 /3 fertilization treatments. The principal component 1 is significantly and negatively correlated with organic matter,available N and P( P < 0. 01),but is significantly and positively correlated with light transmittance( P < 0. 01). The result of CCA indicates that Heleocharis plantagineiformis,Rotala indica and Heleocharis yokoscensis are adapted to the CK treatment,Paspalum paspaloides is adapt to the NPK7 /3 treatment,and Monochoria vaginalis,Lindernia procumbens and Marsilea quadrifolia are adapt to the NPK3 /7 treatment. The number of dominant species and biodiversity in the treatments that combined use organic manure and chemical fertilizers were between that in the CK and NPK treatments. There is a trend that the biodiversity is increased with the increase of organic manure proportion. The biodiversity indices of weed community are significant upward parabola correlative with organic matter and available N and P( P < 0. 01),whereas are negatively correlated with available K( P < 0. 05) and significantly and positively correlated with transmittance( P < 0. 01). 【Conclusions】The weed community features are closely related to the contents of soil organic matter,available N,available P and light transmittance. Balanced fertilization significantly reduces the number of dominant weed species. The treatments that combined use organic manure and chemical fertilizers maintain the number of dominant species and biodiversity between the CK and NPK treatments. These results show that the weed community could be regulated by adjusting the application rate of organic manure for realizing the integrated weed management. Considering both the yield of late rice and biodiversity of weed community,the NPK3 /7 treatment( chemical fertilizer 30% + organic manure 70%) is not only beneficial to obtain high yield,but also shows an advantage for keeping weed biodiversity.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2015年第1期200-210,共11页
Journal of Plant Nutrition and Fertilizers
基金
国际植物营养研究所资助项目(IPNI-HB-34)
湿地演化与生态恢复湖北省重点实验室开放课题资助
关键词
有机肥
杂草群落
土壤养分
生物多样性
organic manure
weed community
soil nutrient
biodiversity