Understanding management effects on soil organic matter and ecological function in forage-based agroecosystems.

世界土壤越来越多地被承认为应对气候变化、营养污染和提供其他关键生态系统服务的潜在贡献。众所周知，包括饲料和服务作物（牧草、干草、覆盖作物）在内的种植系统可以增加碳固存，并为土壤健康和养分循环提供许多好处。特别是，放牧的农业草地通过增加地下生物量显示出很大的固碳潜力;例如，一些研究表明，在采用轮牧（牲畜在围场中频繁轮牧，并允许有足够的休息时间）时，主要以草饲牛肉的生产可能出现温室气体净负排放。需要更好地了解放牧管理和牧场施肥如何影响土壤碳固存，以便更好地促进减缓气候变化。 本建议的目标是确定饲料和服务作物提供的农业生态效益，并确定增加这些效益的管理措施。特别是，我将专注于牛肉生产系统中的放牧管理，以及轮牧策略和氮肥力管理如何影响碳固存。我的研究将检查土壤有机质的质量，以便更好地了解其生态功能（它的稳定性等）。我还将量化土壤健康的好处，包括多年生牧草在轮作制度的能力，以降低肥力的建议，为随后的作物。这些研究问题将通过结合农场，受控环境和研究站的研究来完成。 我的研究计划将提供数据，将进一步科学地了解机制，提高放牧生态系统中的碳封存，并提出建议，使放牧土壤中的土壤碳管理得到改善。这项研究预计将通过确定放牧管理战略，提高其生产力和生态影响（碳封存）在同一时间，以改善牛肉产业的环境成果。这一点很重要，因为牛肉产业经常受到审查，因为它是一个主要的温室气体贡献者，但在放牧期间对土壤碳固存的贡献通常不被考虑。最后，由于使用以牧草为基础的种植制度，促进土壤有机质和土壤健康，土壤质量得到改善，预计将对作为肥料施用的养分量产生影响。实践中，可能会减少营养物质的量，特别是P，在农业中所需的，这是目前的跨部门的优先事项，并为伊利湖流域的健康至关重要。

The world's soils, are increasingly being acknowledged for their potential contribution to the fight against climate change, nutrient pollution, and to provide other critical ecosystem services. Cropping systems that include forage and service crops (pasture, hay, cover crops) are known to increase carbon sequestration and provide numerous benefits to soil health and nutrient cycling. In particular, grazed agricultural grasslands show much potential for sequestering carbon by increasing belowground biomass; for example, some studies have indicated that net negative greenhouse gas emissions are possible for a predominantly grass-fed beef operation, when rotational grazing (where livestock are rotated frequently through paddocks, and allowing adequate rest periods) is employed. An improved understanding of how grazing management and pasture fertilization impact soil carbon sequestration is required in order to better contribute to climate change mitigation.   The objectives of this proposal are to determine the agro-ecological benefits provided by forage and service crops and to identify management practices that increase these benefits. In particular, I will focus on grazing management in beef production systems and how rotational grazing strategies and nitrogen fertility management can impact carbon sequestration. My research will examine the quality of the soil organic matter in order to better understand its ecological function (how stable it is, etc.). I will also quantify the soil health benefits provided by including perennial forage in a cropping system rotation in terms of the ability to lower fertility recommendations for a subsequent crop. These research questions will be accomplished through a combination of on-farm, controlled environment, and research station studies. My research program will provide data that will further scientific understanding on the mechanisms enhancing carbon sequestration in grazed ecosystems and make recommendations to enable improved soil carbon management in grazed soils. This research is expected to improve the environmental outcomes of the beef industry by identifying grazing management strategies that improve their productivity and ecological impacts (carbon sequestration) at the same time. This is important because the beef industry is frequently under scrutiny for being a major greenhouse gas contributor, but contributions to soil carbon sequestration during grazing are typically not considered. Finally, improvements in soil quality due to the use of forage-based cropping systems that promote soil organic matter and soil health are expected to have implications for the amount of nutrients that are needed to be applied as fertilizers. Practices that may reduce the amount of nutrients, particularly P, required in agriculture are needed; this is a current cross-sector priority, and critical for the health of the Lake Erie watershed.