Phosphorus forms and P-sorption properties in three alkaline soils after long-term mineral and manure applications in north-eastern Italy
Phosphorus forms and P-sorption properties in three alkaline soils after long-term mineral and manure applications in north-eastern Italy
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DOI：
10.1016/j.agee.2011.02.011
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发表时间：
2011-04
期刊：
影响因子：
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通讯作者：
D. Pizzeghello;A. Berti;S. Nardi;F. Morari
中科院分区：
文献类型：
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作者：
D. Pizzeghello;A. Berti;S. Nardi;F. Morari
在集约化农业地区，连续施用矿物肥料和有机肥料会导致土壤中磷 (P) 的积累及其吸附能力逐渐饱和，从而增加水生生态系统磷流失的风险。通过结合三种土壤（沙土、粘土和泥炭土）和三种施肥类型（不施肥、农家肥和矿物肥料）的析因实验，研究了土壤磷形态的长期演变（44 年）。测定了钙磷 (PCa)、铁磷 (PFe)、铁+铝磷 (PFe+Al) 形式的磷分布，以及处理对磷有效性的影响（草酸盐可提取-P、Mehlich-3-P、Olsen-P、水可提取-P）。还计算了两个吸附 P 指数和土壤饱和度。土壤磷的形态受到磷输入数量和质量的影响。农家肥导致土壤磷含量持续增加，尤其影响水溶性和不稳定磷的形式（Mehlich-3-P 和 Olsen-P）。易于同化和潜在移动的磷形式与高分子量腐殖质部分的量呈正相关，从而强调了掺入材料的类型及其演变在确定土壤磷行为方面的重要性。使用农家肥以及少量矿物肥料处理的土壤，Olsen-P 超过了 20mgkg−1 阈值，Mehlich-3-P 超过了 150mgkg−1 阈值，从而证明了水体磷流失的潜在风险。虽然从绝对值来看，在粘土和泥炭土中观察到更一致的积累，但沙土的磷含量尤其值得关注，因为它们的磷吸附能力较低，饱和度较高。在土壤 P 测试中，Mehlich-3-P 被证明是评估意大利农艺和环境土壤条件的最佳指标。
In areas of intensive agriculture continuous applications of mineral and organic fertilizers can lead to an accumulation of phosphorus (P) in the soils and progressive saturation of their sorption capacities, increasing the risk of P losses to aquatic ecosystems. The long-term evolution (44years) of soil P forms has been studied in a factorial experiment combining three soils (sandy, clay and a peaty) with three types of fertilization (no fertilizer, farmyard manure and mineral fertilizer). The P distribution in the calcium P (PCa), iron P (PFe), iron+aluminium P (PFe+Al) forms, and the effect of treatments on P availability (oxalate extractable-P, Mehlich-3-P, Olsen-P, water extractable-P) were determined. Two sorption P indices and the degree of soil saturation were also calculated. Soil P forms were affected by both quantity and quality of P inputs. Farmyard manure caused a more consistent increase in soil P content, affecting the water soluble and labile P forms (Mehlich-3-P and Olsen-P) in particular. Readily assimilable and potentially mobile P forms were positively correlated with the amount of high molecular weight humic fractions, thus stressing the importance of the type of incorporated materials and their evolution in determining soil P behaviour. Soils treated with farmyard manure, and to a lesser extent with mineral fertilizer, exceeded the threshold values of 20mgkg−1for Olsen-P and 150mgkg−1for Mehlich-3-P, thus evidencing a potential risk of P loss to water bodies. While in absolute terms the more consistent accumulations were observed in clay and peaty soils, the P content of sandy soils is of particular concern, given their lower P sorption capacity and higher degree of saturation. Among the soil P tests, Mehlich-3-P proved to be the best indicator to assess Italian soil conditions for both agronomic and environmental purposes.