Polyphosphate hydrolysis, sorption, and conversion in two different soils

作者：Rongwei Zhou, Jian Zhou, Lulu Jia, Jinju Wei, Jiaxin Yan, Jianhua Ji, Zongqiang Wei · 发表于：European Journal of Soil Science · 年份：2023 · DOI：10.1111/ejss.13341 · 被引用次数：17 · 研究领域：Phosphorus and nutrient management、Iron oxide chemistry and applications、Soil and Water Nutrient Dynamics

Abstract Polyphosphate fertilizer is an alternative to traditional orthophosphate fertilizer, but it is unclear whether it provides greater soil phosphorus (P) mobility and availability than orthophosphate fertilizer. This study aimed to examine the chemical behaviour of polyphosphate after its application to the soil. The hydrolysis, sorption, and P transformation of two types of polyphosphate fertilizers (short‐chain and long‐chain) were examined for two types of soils (acidic Acrisol and calcareous Cambisol), with orthophosphate serving as the control treatment. 31 P NMR spectroscopic analyses indicated that polyphosphate in soil was rapidly converted to pyrophosphate, which was then hydrolyzed to orthophosphate at a slower rate. In general, in the calcareous Cambisol, the addition of short‐chain polyphosphate fertilizer resulted in greater soil P mobility as measured by greater soil pore water orthophosphate concentration than the control. Thus, short‐chain polyphosphate fertilizer tended to be more effective than orthophosphate in calcareous soils. This was in contrast to the result of an aqueous incubation experiment, in which a lower pH increased the rate of polyphosphate hydrolysis. Indeed, in both soils, the sorption of total P was greater when P was added as polyphosphate than when it was added as orthophosphate. Moreover, polyphosphate sorption appeared to be mainly controlled by soil iron and aluminium minerals, because the Acrisol showed stronger polyphosphate so...