Natural Resources Institute Finland, Natural Resources, Yliopistokatu 6B, FI-80100, Joensuu, Finland.
Natural Resources Institute Finland, Natural Resources, Tietotie 4, FI-31600 Jokioinen, Finland.
J Environ Manage. 2024 Jan 1;349:119388. doi: 10.1016/j.jenvman.2023.119388. Epub 2023 Oct 27.
Food production has a profound eutrophication impact on waterbodies via nutrient leaching. To provide reliable life cycle assessments of the eutrophication potential of agricultural products, accurate nitrogen leaching models are needed. Although many dynamic nitrogen leaching models are in use, their suitability for farm-level assessments remains limited when their requirements for site specific data or numerous parameters are not met. In Finland, less data intensive leaching models for life cycle assessments have been developed using data from conventional farming, however, the suitability of these models for organic farming remains unknown. In this work, we developed new nitrogen leaching models that are applicable to both conventional and organic production. While this paper does not aim to argue in favor of organic or conventional farming it provides tools that can be used to inform decisions about management practices from the environmental perspective. We utilized up to 16 years of field measurements from two leaching fields in Finland. We developed prediction equations for nitrogen leaching for two soil types: sand soil and clay soil. According to our statistical analysis based on the data, the relevant factors for explaining nitrogen leaching included soil type, rainfall, whether the farming is done organically, and the availability of nitrogen for leaching. Computed nitrogen balance as such was found to be a poor proxy for nitrogen available for leaching, while nitrate nitrogen concentration measurement of the soil carried out in the fall was found to be a valuable predictor. Organic farming, with a crop rotation resembling that of conventional farming, resulted on average in 20% less nitrogen leached per hectare as compared to conventional farming with 95% C.I. [-34%, -3%]. The developed models are suitable for integration into a life cycle assessment framework, and especially the models utilizing nitrate nitrogen were shown to be applicable to a wide range of different crop types, making the model well-suited for plots with diverse crop rotations.
食物生产通过养分淋溶对水体产生深远的富营养化影响。为了对农产品的富营养化潜力进行可靠的生命周期评估，需要准确的氮淋溶模型。尽管有许多动态氮淋溶模型在使用，但当它们的要求无法得到满足时，如需要特定地点的数据或大量参数，它们在农场层面评估中的适用性仍然有限。在芬兰，已经开发了使用常规农业数据的、较少依赖数据的生命周期评估氮淋溶模型，但这些模型是否适用于有机农业仍不清楚。在这项工作中，我们开发了适用于常规和有机生产的新氮淋溶模型。虽然本文不是为了支持有机或常规农业而撰写，但它提供了可以从环境角度为管理实践决策提供信息的工具。我们利用了芬兰两个淋溶场长达 16 年的田间测量数据。我们为两种土壤类型（沙土和粘土）开发了氮淋溶预测方程。根据我们基于数据的统计分析，解释氮淋溶的相关因素包括土壤类型、降雨量、耕作方式（有机或常规）以及氮的淋溶可用性。我们发现，计算的氮平衡本身并不是氮淋溶可用量的良好指标，而秋季土壤中硝酸盐氮浓度的测量则是一个有价值的预测指标。与常规农业相比，轮作方式类似于常规农业的有机农业平均每公顷氮淋溶量减少 20%，置信区间为 95%[-34%，-3%]。开发的模型适合整合到生命周期评估框架中，特别是利用硝酸盐氮的模型被证明适用于广泛的不同作物类型，使得模型非常适合具有不同作物轮作的地块。
