Agricultural nitrogen loading is a leading cause of eutrophication within the Chesapeake Bay. Agriculture in the Commonwealth of Pennsylvania is responsible for a large portion of the nitrogen load entering the bay. Vegetated riparian buffers are a common agroforestry practice used to intercept surface runoff and subsurface leaching of nutrients such as nitrogen from upland agricultural fields. Watershed-wide nutrient credit trading has been suggested as a mechanism for reducing nutrient pollution entering the Chesapeake Bay. The cost of producing nitrogen credits through the establishment of riparian buffers on Pennsylvania farmland was analyzed to determine if nitrogen credit trading could provide an incentive for buffer establishment. Forest buffers were shown to have marginally lower nitrogen credit production costs and payback periods than grass filter strips. Larger riparian buffers were shown to have higher credit production costs than smaller buffers due to increases in establishment costs outpacing increases in nitrogen credit trading revenue. Nitrogen credit trading was determined to be an inadequate incentive for agricultural riparian buffer establishment due to the high cost of producing nitrogen credits. Furthermore, nitrogen credit trading was shown to be less lucrative compared to the Conservation Reserve Enhancement Program, a common riparian buffer cost share program. However, increases in the market price of nitrogen credits or bundling nitrogen with other nutrient credits such as phosphorus could ultimately result in credit trading providing an adequate incentive for agricultural riparian buffer establishment. These results could be used to guide the framework for nutrient credit trading programs within other watersheds.

农业氮负荷是切萨皮克湾富营养化的主要原因。宾夕法尼亚州的农业是进入海湾的很大一部分氮负荷的原因。植被的河岸缓冲带是一种常见的农林业实践，用于拦截地表径流和地下营养物（例如来自高地农田的氮）的地下浸出。人们建议在流域范围内进行营养素信贷交易，以减少进入切萨皮克湾的营养素污染。分析了通过在宾夕法尼亚州农田上建立河岸缓冲带而产生氮信用的成本，以确定氮信用交易是否可以为缓冲带的建立提供动力。结果表明，与草滤带相比，森林缓冲带的氮信用生产成本和投资回收期略低。事实表明，较大的河岸缓冲带比较小的缓冲带具有更高的信贷生产成本，这是因为基础设施建设成本的增长超过了氮信用交易收入的增长。由于生产氮信用额的高成本，氮信用额交易被认为不足以刺激农业河岸缓冲带的建立。此外，与普通的河岸缓冲成本分摊计划“保护储量提高计划”相比，氮信用交易的利润更低。然而，氮信用额的市场价格上涨或将氮与其他营养信用额（例如磷）捆绑在一起，最终可能导致信用交易为建立农业河岸缓冲带提供足够的动力。这些结果可用于指导其他流域内的营养素贸易计划框架。