Assessing cover cropping options for improved forage yield, quality and soil health in a boreal climate

覆盖作物正被纳入北美温带经济作物生产系统。然而，在北方气候（纽芬兰和拉布拉多-NL）的经济作物轮作中确定和纳入适当的CC混合物，以及它们对土壤物理，化学和生物特性，氮（N）动态和温室气体排放（GHGE）的影响尚不清楚。北方气候的特点是生长季节短，温度较低。北方地区种植的经济作物一般在6月的第一周播种，10月的第三周收获，因此收获后的生长季节很短。在北方气候条件下，在经济作物上间作CC混播和定植，可以提高牧草产量和品质，改善土壤理化和生物学性状，减少土壤侵蚀和氮素淋失，最终减少温室气体排放。我将使用不同的CC混合物进行现场实验，以：1）评估CC混合物在青贮玉米-蚕豆轮作中的饲料潜力，2）用选定的CC混合物测定4年以上青贮玉米和蚕豆的饲料产量稳定性和品质，3）测量GHGE、土壤矿物N动态、N淋溶和青贮玉米-蚕豆轮作中CC混合物的植物N吸收，4）评估CC混合物对土壤质量和健康的影响（土壤有机C和N库;酶活性;和微生物生物量组成、多样性和丰度）。这项研究计划将找到合适的CC混合物，可以成功地在短生长季节在北方气候，并将提供一些额外的高品质饲料。用CC混合物生产高质量的饲料将减少饲料进口，碳足迹，提高畜牧业和乳制品行业的盈利能力和自给自足能力，以及该省迫切需要的整体饲料安全。这项研究计划将为政策制定者、联邦和省级政府机构提供新的科学知识，帮助他们重新定义种植系统，以实现气候变化情景下的粮食安全。最重要的是，它将提高土壤质量和健康，减少土壤侵蚀，并将在北方气候中建立可持续和生产性的牧草覆盖种植系统。该研究计划将提高四名本科生，三名硕士，两名博士生和一名PDF的跨学科研究能力建设（农学，植物生理学，土壤科学，生物化学，微生物学和水文学），专业知识和田间实验设计技能，采用一系列实验室和现场设备，数据收集，分析技术和沟通技能，为下一代研究人员做好准备，教师和行业利益相关者，以加强粮食安全，同时保护环境。研究结果将有助于发展新的低硝化和低N2 O种植系统，对社会和生态系统产生更大的影响。

Cover crops (CCs) are being integrated into the temperate North American cash crop production systems. However, identification and inclusion of appropriate CC mixtures in cash crop rotation in boreal climate (Newfoundland and Labrador-NL), and their effects on soil physical, chemical and biological properties, nitrogen (N) dynamics and greenhouse gas emission (GHGE) is not known. Boreal climate is characterized as a short growing season and cooler temperature. Cash crops grown in boreal region are generally seeded in first week of June and harvested in 3rd week of October, so very short growing season left after harvest. Interseeding of CC mixture and establishment in cash crops in boreal climate can enhance additional forage production and quality, and improve soil physiochemical and biological properties, and reduce soil erosion and N leaching losses, and eventually GHGE. I will conduct field experiments using different CC mixtures to: 1) assess the forage potential of CC mixtures in silage corn-faba bean rotations, 2) determine the forage yield stability and quality of silage corn and faba bean over 4 years with selected CC mixtures, 3) measure GHGE, soil mineral N dynamics, N leaching, and plant N uptake in CC mixtures in silage corn - faba bean rotation, 4) assess the effects of CC mixtures on soil quality and health (soil organic C and N pools; enzyme activities; and microbial biomass composition, diversity, and abundance). This research program will find suitable CC mixtures that could be successfully grown in short growing season in boreal climate and will provide some additional high quality forage. High quality forage production from CC mixtures will reduce the forage import, carbon footprints, enhance the profitability and self-sufficiency of the livestock and dairy industry and overall feed security in the province which is direly needed. This research program will generate new scientific knowledge for policy makers, federal and provincial government agencies related with agriculture, environment and climate in redefining cropping systems to achieve food security in climate change scenario. Most importantly, it will enhance soil quality and health, reduce soil erosion and will build sustainable and productive forage cover cropping system in boreal climate. This research program will enhance the capacity building of four undergraduate, three master, two PhD students and one PDF in interdisciplinary research (agronomy, plant physiology, soil science, biochemistry, microbiology and hydrology), expertise and skills in designing of the field experiments, employing a range of laboratory and field equipment, data collection, analytical techniques and communication skills to prepare next generation researchers, faculty and industry stakeholders to enhance food security while protecting the environment. Findings will aid in the evolving of novel low-nitrifying and low N2O- cropping systems, with greater impact on society and ecosystems.