间作控病对产量优势贡献的定量评估及其响应氮调控的机制

Modern agriculture has resulted in the frequent occurrence and epidemic cycles shorten of crop diseases, and enhanced severe yield loss and excessive application of chemical fungicide. Intercropping is an effective practice with long history in crop production in China, and has been widely accepted due to its yield advantage and disease control. Numerous previous studies about intercropping mainly focused on the efficient utilization of resources and yield advantage, effect and mechanism of a single main disease control etc, little information is known about the relationship of disease infections and yield loss, especially no literatures cited the effects of multiple disease damages on yield loss in intercropping system. Quantitative assessment the yield advantage contribution through disease control in intercropping is only few reported so far. Recent studies showed that when multiple damages are considered, the corresponding yield reduction is smaller than the accumulation of individual yield reductions. When individual damage is considered alone, the corresponding yield losses will be overestimated. Our previous researches showed that wheat and faba bean intercropping significantly increased crop yield and decreased main diseases occurrence, and disease control effect and yield advantage of intercropping were influeced by nitrogen levels. Therefore, the objectives of this study are to investigate disease multiple damage characteristics under field conditions, using multivariate statistical analysis methods to study the effect of multiple disease damages on crop yield losses in intercropping system, to quantify the yield advantage contribution through disease control of intercropping，and to indentify the response mechanism of multiple disease damages to nitrogen regulation. The results of this study will be beneficial for using biodiversity as means to increase crop yield, decrease disease damages and sustainable agricultural development.

现代农业生产导致作物病害频繁发生，病害流行周期越来越短，造成作物减产和过量使用化学农药等严重问题。合理间作不仅能显著增加作物产量，而且是持续控制病害的有效措施。长期以来，间作研究主要集中在资源高效利用与产量优势及单一病害控病效果与机制方面，对病害危害与产量损失的研究较少，尤其是病害复合危害对产量损失的影响及间作控病在间作产量优势中的定量评估尚缺乏研究。最近研究显示病害复合危害减产效应小于单一病害危害累加之和。我们的前期研究表明，小麦//蚕豆显著降低主要病害的发生并具有产量优势，且间作控病效果和产量优势受氮水平的影响。因此，本项目拟以小麦//蚕豆体系为研究对象，通过大田试验和多元数据统计方法研究间作系统病害复合危害对作物产量损失的影响进而定量评估间作控病在产量优势中的贡献，探讨间作系统病害复合危害对氮肥调控的响应。为应用生物多样性持续控制作物病害，提高产量，实现农业可持续发展提供理论依据。

现代农业追求大面积种植单一作物和农药化肥的大量施用造成农田生态系统日趋简单和脆弱，使作物病害发生频繁，病害流行周期越来越短，造成作物减产。长期以来，间作系统大量的研究多集中在资源高效利用与增产效果，有关间作控病对作物产量优势的贡献程度目前尚不清楚。本项目通过田间小区试验，研究间作系统病害复合危害特征，量化病害复合危害造成的产量损失进而定量评估间作控病对产量优势的贡献程度，从复合危害角度量化每一种病害造成的产量损失。阐明间作系统氮肥调控对病害复合危害的影响，揭示间作控病-氮肥施用-产量优势的互作效应。. 研究表明，蚕豆赤斑病发病率及病情指数明显高于锈病，施氮加重了蚕豆赤斑病和锈病的总体危害程度，间作则显著减轻赤斑病和锈病危害。回归分析表明，每增加一个单位的赤斑病和锈病AUDPC值可造成1.4 kg•hm-2～1.6 kg•hm-2的籽粒产损失。间作控病增产效果平均挽回蚕豆籽粒产量损失330.1 kg•hm-2～539.7 kg•hm-2，占间作产量优势总效应增产量的51%～57.2%。赤斑病和锈病复合危害时，赤斑病是造成蚕豆籽粒产量损失的主要病害，锈病次之。间作控制赤斑病挽回产量损失对间作产量优势的贡献更大。各施氮水平下LER都大于1，LER随施氮水平的增加而降低，适宜施氮水平 (45 kg•hm-2～90 kg•hm-2) 下间作控病挽回的产量损失最大。在高肥力土壤条件下施氮主要通过改变田间微气候间接影响蚕豆病害发生，而在低肥力土壤条件下，蚕豆病害发生受氮营养和田间气候条件的联合影响。本研究结果为探索间作提高作物产量、持续控制病害、减少化肥和农药施用、实现环境友好的可持续农业生产提供科学理论依据。. 通过项目实施，发表学术论文12篇，其中SCI论文3篇，核心期刊论文9篇。获国家实用新型专利授权5项，出版学术专著1部。培养硕士研究生6人，1人公派赴荷兰Wageningen大学进行学术研究，1人晋升高一级职称。参加国内外相关学术会议12人次。