长期有机–无机肥配施对农田杂草土壤种子库的影响

为揭示长期有机-无机肥配施处理下农田杂草土壤种子库的特征变化规律，本研究通过田间长期定位施肥模式试验，运用群落生态学方法研究了小麦-大豆轮作制度下大豆种植季7种施肥处理区杂草土壤种子库的结构及其生物多样性特征。结果表明，土壤样品中共检出杂草种子16种，隶属于10科； 土壤种子库总密度分布在15995~106300 grain/m2范围。长期有机-无机肥配施处理区的杂草土壤种子库优势物种组成较为简单，优势种为12种，配施麦秸处理区主要以栗米草为主，配施粪肥处理区主要以水苋菜为主； 土壤种子库的密度显著降低至15995~41900 grain/m2范围； 物种丰富度降低至7.67~9.33范围，并且将物种多样性和均匀度指数维持在休闲与纯化肥处理区之间（1.5~2.0和0.6~0.8）。长期配施麦秸、 粪肥均显著影响土壤杂草土壤种子库的结构特征，且麦秸与粪肥品种间差异的影响大于麦秸施用量差异的影响。因此，本研究认为有机-无机肥配施既有利于作物的优质高产，也可以通过调整有机肥种类以及与施用量来调控杂草土壤种子库，实现经济效益和生态效益的双赢。

Effects of long-term mixed application of organic manure and chemical fertilizers on farmland weed soil seedbank

 The effect of long-term mixed application of organic manure and chemical fertilizers on farmland weed soil seedbank was evaluated in this study. The weed soil seed bank’s structure and biodiversity characteristics were studied by using the community ecology method under seven different fertilization treatments at soybean cultivating season of the wheat-soybean cropping system. The results show that all the weed seeds affiliated with sixteen species and ten families are detected, and the weed soil seed density is from 15995 to 106300 grain/m². In the treatments with mixed organic manure and chemical fertilizers, the composition of weed species is relatively simple, and the number of the dominated species is from 1 to 2.  In the treatment with mixed wheat straw and chemical fertilizers, the dominated species is Mollugo pentaphylla, and in the treatment with mixed manure and chemical fertilizers, the dominated species is Ammannia baccifera. The density of weed soil seedbank is reduced in the range from 15995 to 41900 grain/m². The species richness is reduced in the range from 7.67 to 9.33, and the Shannon-Wiener index and Pielou index are in the range of those of the CK2 and NPK treatments (from 1.5 to 2.0 and from 0.6 to 0.8). Types and application amounts of applying organic fertilizers affect the weed species structure features significantly, and the influences of organic fertilizer types are greater than those of application amounts of wheat straw. The results of this paper show that the mixed application of organic manure and chemical fertilizers not only has beneficial to get high yield, but also regulates weed soil seedbank by adjusting the types and application amount of organic fertilizer to achieve economic and ecological benefits.