Despite the agricultural expansion into Canada's boreal ecoregion, little is known about the phosphorus (P) adsorption capacity in natural and managed Podzols' soil profiles. This information is critical for informing management decisions for P use efficiency and mitigating related environmental risks. Thus, this study aimed to evaluate P adsorption characteristics of podzolic horizons in natural and managed soil using nonlinear Langmuir and Freundlich adsorption models. A batch adsorption experiment was conducted using soils collected from distinct horizons of forested and managed fields in eastern and central Newfoundland, Canada. Nonlinear Langmuir and Freundlich fitted models had r values >.99 regardless of horizons, locations, and management history. The organic LFH, a surface horizon typical for forested Podzols, and a long‐term managed Ap horizon had the highest P retention capacities when compared to either newly converted soils or soils used as tree nursery following conversion from natural forest. A significant linear correlation and multiple regression models (p < .05) were established between P adsorption parameters and selected soil properties. Results suggest that following conversion from forest to agricultural use, long‐term management that includes tillage and lime and fertilizer application creates an Ap horizon with strong adsorption capacity, which could still fix P and serve as a source of P. The newly converted soils and the deeper soil horizons, for both natural and converted lands, do act mainly as P sinks; hence, crops may need larger quantities of P fertilizer increasing fertilizer expenses and also increasing future legacy P.

中文翻译：

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人工林和人工林土壤对磷的吸附特征

尽管农业已经扩展到加拿大的北部生态区，但人们对自然和管理的Podzols土壤剖面中磷（P）的吸附能力知之甚少。此信息对于告知管理决策以提高磷的使用效率和减轻相关的环境风险至关重要。因此，本研究旨在使用非线性Langmuir和Freundlich吸附模型评估天然土壤和管理土壤中Podzolic层对P的吸附特性。使用从加拿大纽芬兰东部和中部森林和管理土地的不同视野收集的土壤进行了批量吸附实验。非线性Langmuir和Freundlich拟合模型有[R值> .99，与范围，位置和管理历史记录无关。与新近转化的土壤或天然林转化后用作苗圃的土壤相比，有机LFH，典型的林用足动物的地表层和长期管理的Ap层层具有最高的P保持能力。显着的线性相关和多元回归模型（p在P吸附参数和选定的土壤特性之间建立<0.05。结果表明，从森林转换为农业用途后，包括耕作，石灰和化肥施用在内的长期管理创造了具有强大吸附能力的Ap视野，该视野仍可固定P并作为P的来源。对于自然和转化土地而言，更深的土壤层主要起着P汇的作用；因此，农作物可能需要大量的磷肥，从而增加化肥支出，并增加未来的遗留磷。