生态学长期研究促进资源高效利用和区域农业可持续发展

华北平原农业的高强度水肥投入造成严重地下水超采和氮素污染风险。中国科学院栾城农业生态系统试验站立足农田生态系统的长期生态学监测和研究,围绕农业资源高效利用和可持续发展,建立了农田土壤-作物-大气系统(SPAC)界面节水调控理论与技术,提出基于农田水平衡的休耕轮作和适水型种植制度调整思路,阐明了农田碳氮循环特征和温室气体排放及硝酸盐淋失通量,在厚包气带水盐运移和硝酸盐转化和削减机理方面取得突破性认识,研发了农田生产信息快速获取和精准管理的技术产品与平台,并与农业发展紧密结合,集成了系列农业生产技术模式,为区域农业的优质高效发展和水资源可持续利用提供了理论和技术支撑。

Long-term Ecological Research (LTER) Promotes Natural Resources Use Efficiency and Agricultural Sustainable Development in North China Plain

North China Plain has achieved great success in pursuing high grain productivity in the past decades, however, the achievements in grain yield promotion was largely relies on great inputs of water and fertilizer, and already caused severe ecological problems, such as groundwater level decline and nitrate leaching. With focusing on the sustainable agriculture especially on the aspects of groundwater depletion and contamination risk, Luancheng Agro-ecosystem Experimental Station (LAES) has conducted a series of experiments or measurements since it was established in 1981, in order to explore the mechanisms of improving the water and nutrients use efficiency. With the efforts of several generations, we have revealed the mechanisms of water transferring in soil-plant-atmosphere continuum (SPAC) and established an interface regulatory theory for water saving agriculture. The interfaces refer to interfaces between soil and roots, leaf and ambient air, soil surface and air. According to more than 10 years of continuous field measurement of water and heat fluxes over the predominant wheat-maize double cropping system, we proposed an alternative cropping pattern of 4 crops in 3 years based on the seasonal and annual water budgets analysis. We also clarified the characteristics of carbon and nitrogen cycles in the irrigated wheat-maize field, determined GHGs emission and nitrate leaching fluxes, made some breakthroughs in nitrate transport and transformation in deep vadose zone, and nitrate reduction pathways in deep soil layers. We also developed some information technologies to increase the resource use efficiency and improve field management, such as portable leaf nutrient diagnosis system using smart phone camera, regional soil wetness and fertility monitoring and irrigation supporting system, etc., and assembled large amount of cultivation technology packages and production patterns in the past 30 years. With good applied effects, the innovations in both resource use theory and technologies have received wide attentions praise from farmers and governmental authorities. We will continue to research and develop innovative knowledge and technologies with considering the agricultural revolutions happening nowadays and provide great decision supporting for policy makers in future.