Which approach makes the most cents? Evaluating the effect of land conversion practices on soil health and yields of barley and oats

气候变化正在为北方地区的农业扩张创造机会，这将需要将森林和灌木丛转变为生产性田地。从历史上看，由于有机物对土壤的回报较低，以及有利于现有储存物分解的条件，转换导致土壤有机物“库”损失高达50%。这些损失可能会侵蚀土壤健康，因为有机物质在决定土壤的物理、化学和生物特性方面发挥着关键作用，而土壤的健康是其核心。通过覆盖和深松过程将木质生物质留在现场可以减轻这些损失，同时是土地转换的最快速和最具成本效益的方法，但存在知识空白，需要进行拟议的研究。覆盖后第二年产量显著下降，需要施用大量肥料，尚未研究将有机物留在现场的长期效益，并且尚不清楚已建立的土壤健康指标（例如康奈尔土壤健康评估（CSHA））是否适用于更北方气候。 本项目将通过以下方式解决这些差距：1。研究土地转换对土壤健康和土壤有机质的长期影响，并通过测量和比较北方安大略常规覆盖和清除的农场土壤健康指标，确定监测北方安大略土壤健康变化的最佳指标，2.建立一个田间试验，以研究木质残留物掺入（时间和位置），施肥率和轮作策略对燕麦和大麦产量的影响，燕麦和大麦是北方安大略的两种主要粮食作物，土壤健康和土壤有机质储存，以及3.确定土地清理实践的利润率，以确定对安大略粮农最有效、最经济和最可持续的方法。

Climate change is creating opportunities for agricultural expansion in northern regions, which will demand the conversion of forest and scrub-brush to productive fields. Historically conversion has resulted in losses to the "bank" of soil organic matter of up to 50% because of lower returns of organic matter to the soil and conditions that favor decomposition of existing stores. These losses presumably erode soil health because of the key role organic matter plays in determining the physical, chemical and biological properties of the soil, the heart of its well-being. Leaving woody biomass on-site through the process of mulching and subsoiling could mitigate these losses, while being the most rapid and potentially cost-effective method for land conversion, but there are knowledge gaps that beg for the proposed research. Significant declines in yield in the second year after mulching have required the application of large amounts of fertilizer, the longer term benefits of leaving organic matter on-site have not been studied, and it is unknown if established indicators of soil health e.g. Cornell Soil Health Assessment (CSHA) are applicable in more northern climates. This project will address these gaps by: 1. examining the longer term effects of land conversion on soil health and soil organic matter and identifying the best indicators for monitoring change in soil health in Northern Ontario through measurements and comparisons of indicators of soil health on farms that have mulched and cleared conventionally in Northern Ontario, 2. establishing a field trial to examine the effects of woody residue incorporation (timing and placement), rate of fertilizer application, and rotation strategy on yields of oats and barley, two key grain crops in Northern Ontario, soil health and soil organic matter stores, and 3. determining the profit margins of land clearing practices to identify the most effective, economical and sustainable approach for Ontario's grain farmers.