【作者】 马波；

【导师】 强胜；

【作者基本信息】 南京农业大学 ， 植物学， 2004， 硕士

【摘要】 本文以江苏省农田杂草综合体为研究对象，选取有代表性的旱连作田样点和稻麦连作田样点进行种子库取样，利用水洗计数的方法研究了两种类型农田潜杂草群落的结构特征，并结合环境条件利用典范对应分析进行潜杂草群落的区系研究；利用保湿萌发的方法比较研究两种类型农田的潜杂草群落的特征，利用淹水处理萌发种子库，比较研究两种类型农田潜杂草群落的发生数量，探讨水旱轮作的治草机理；同时利用萌发和水洗计数的方法研究旱连作田潜杂草群落，比较研究两种方法不同之处；对取样地进行显杂草群落调查，结合潜杂草群落的结果，阐述农田潜显性杂草群落综合体的结构特征；选用异丙隆和敌草强、都尔进行复配筛选研究，两配方对控制潜显性杂草群落综合体都有很好的效果。详细结果如下： 1、江苏省农田潜杂草群落结构特征 采用水洗计数的方法对江苏地区12个旱连作样点和19个稻麦连作田样点杂草种子库进行了研究。一般情况下，两种类型农田杂草种子库中都同时包括三种类型杂草，具有水田杂草的样点，其夏熟作物田杂草多以湿生性杂草如看麦娘等为主，反之，则以旱生性杂草为主；共统计到48种杂草，稻麦连作田中发现43种，旱连作田中出现36种，其中禾本科杂草最多，其次为莎草科；异型莎草和通泉草在两种类型农田杂草种子库中出现频率最高，种子库数量很大；杂草种子库密度地区变化很大，稻麦连作田种子库数量明显多于旱连作田，但是两种农田杂草种子库0-10cm土层内种子数量占0-15cm的60％-90％，在土层中递减式分布；耕作方式和种植制度相对稳定的田块，种子库的结构相对稳定，翻耕地或深耕地的土壤种子库的垂直分布相对均匀。典范分析结果表明影响农田种子库主要因素是农田的种植制度，其次为土壤pH，人为管理水平也有很大影响。 2、种植制度和水分管理对潜杂草群落的影响 采用温室保湿萌发的方法对旱连作田和稻麦连作田潜杂草群落进行了调查，结果表明潜杂草群落(种子库)的结构特征同水洗计数的方法相似，但在数量上相差较大，其中夏熟作物田杂草数量都占很大部分。不同水分条件萌发的结果表明，长期不变的种植制度下实施水旱轮作更为有效，否则应采取必要的预防措施。 3、水洗法和温室萌发法对旱连作田潜杂草群落的比较研究 利用萌发和水洗同时研究旱连作田杂草种子库发现，保湿萌发的方法获得种类最多，其次为水洗计数和淹水处理，数量上则是水洗计数的最多，淹水处理最少，结果江苏省农田杂草综合体及其复配除草剂筛选控制的研究差异很大，所以应根据具体研究目的来选择适合的研究方法.4、农田杂草群落综合体的研究 农田杂草危害是基于地上当季1个“显”杂草群落和地下2一3个“潜”杂草群落构成的杂草群落综合体.两种类型农田的潜杂草群落和显杂草群落的主要优势种类及其相似杂草比例，定性相似性指数较高，数量上相差很大.部分杂革具有很大的种子库数量，但其危害性不大，而在种子库内数量不大，田间危害程度较大，因而杂草的综合治理需研究潜显性杂草群落综合体的结构特征，结合杂草的生物生态学特性，提出科学合理生态的杂草治理方案.5、除草剂复配筛选研究 选择异丙隆和4种耽胺类除草剂复配，以本实验室专利产品麦革隆作对照药剂，进行配方筛选，结果表明异丙隆和都尔1:1.5，用量3压60g.a.i/mu，用于棉花田;异丙隆和敌草强1:2，用于玉米田，用量30一60g.a.i/mu，可土壤处理或茎叶处理，可有效控制潜显性杂草群落综合体.关键词:种子库;萌发;水洗;综合体;除草剂复配更多还原

【Abstract】 Weed community complexes of summer, autumn crop and paddy fields in Jiangsu Province were studied. Soil weed seed banks (potential weed communities) were sampled in representative continuous dry-cropping and rice-wheat rotation fields. Elutriation of sampled soil and account of weed seeds were used to study characteristics of the potential weed communities in these two kinds of farmlands, and canonical correspondence analysis (CCA) was applied to study the flora of potential weed communities associated with environmental conditions. Keeping wet, the weed seeds in soil banks were germinated in greenhouse to analyze the characteristics of potential weed communities of two different cropping systems; and also keeping submerged to compare the two methods’ weed germination quantities of two kinds of cropping systems, to discuss the mechanism of weed control effect of rice-dry rotation systems. Germination and elutriation were used to study potential weed communities of continuous dry-cropping fields to compare the difference between the two methods. Real weed communities were surveyed to explain the comprehensive structure characteristics of real and potential weed community complexes integrated with the results of the potential weed community structure. Isoproturon plus DiCaoQiang and isoproturon plus metolachlor two mixture had good control effect on potential and real weed communities. The detailed results are as following: 1. The structure characteristics of potential weed communities in Jiangsu ProvinceWeed seed banks of 12 samples of continuous dry-cropping and 19 samples of rice-wheat rotation fields were studied through using elutriation. Normally, all weed seed banks include three types of weeds in two different cropping systems; and if weeds in included paddy weeds, there were more hydrophilous weeds in summer maturity crop fields, such as equal alopecurus (Alopecurus aequalis Sobol.), contrarily, more xerophilous weeds. Through counting sampled soil seedbank, 48 weeds were recorded. Among them, 43 weeds were found in seed bank of rice-wheat rotation fields, 36 in continuous dry-cropping fields, of which gramineae (Poaceae) is the most, the second sedge family (Cyperaceae).Difformed galinagle (Cyperus difformis L) and Japanese Mazus {Mazus japonicus (Thunb.) O. Kuntze) had the highest frequency and the largest amount of seed bank density in fields of two kinds of cropping systems. There were the marked differences of seed bank density in different fields, and seed density of rice-wheat rotation fields were much higher than that of continuous dry-cropping fields. 60%-90% seeds were found in 0-10 cm soil layer in fields of two kinds of cropping systems with distributing decreasingly in the lower soil layers. Seed bank structure was relatively stable in the fields with stable cultivation and cropping systems; and the vertical distribution of seeds in the fields under deep-ploughed was relatively even. The results of canonical correspondence analysis showed that cropping systems was the main factor influencing seed bank structure, and the second was soil pH. The artificial management level had very great influence too.2. The influence of cropping system and water condition to potential weed communitiesUsing induced emergence under keeping wet in greenhouse, potential weed communities of continuous dry cropping and rice-wheat rotation fields were investigated. Results indicated that compositions of the seed bank were similar to the results of elutriation, but the size of each weed species was different in which most of the weed seeds belonged to summer crop fields. The results under different water conditions in germination indicated that rice field-upland field rotation could control weeds effectively after a long time of the same cropping systems, otherwise the essential precautionary measures should be taken.3. Comparison of characteristics of potential weed communities in continuous dry-cropping systems with elutriation and induced emergenceUtilizing emergence inducement and elutriation to study weed seed banks o更多还原