How does the Hedley sequential phosphorus fractionation reflect impacts of land use and management on soil phosphorus: A review

Abstract

The Hedley sequential‐phosphorus (P)‐fractionation method has been used in many countries to study the effects of land‐use and management systems on soil P. Many data sets have been obtained but collectively never have been considered or to goal topic reviewed. Therefore, the objectives of this review were to compile and systematically evaluate these data. The data generated over many years were grouped into temperate, and subtropical and tropical soils of different land use and duration of soil‐management studies. In natural ecosystems, vegetation types and composition and percent of vegetation covers substantially affected all P fractions with pronounced impacts on the labile and moderately labile P. In short‐term studies (≤ 10 y), changes in the labile and moderately labile inorganic P (Pi) fractions were detected when more P (e.g., by factor 5) was applied than commonly recommended for agricultural crops. However, without P application the changes in all P fractions were subtle in temperate soils, but declines were significant in labile and moderately labile P in subtropical and tropical soils. In both temperate and tropical climates, medium (10–25 y) and long‐term (>25 y) cultivation without P application depleted all P fractions, whereas most of P fractions increased with continuous P application, regardless of the amount and source of P. Synthesis of data resulted in multiple‐regression functions which described differences in labile and moderately labile P fractions as function of differences in amount of P application and duration of the experiments. Moreover, the correlation analysis also showed strong association among most of the P fractions. Current limitations in data interpretation of Hedley fractionation can be overcome by the application of 31P nuclear–magnetic resonance (NMR) and X‐ray absorption near‐edge fine‐structure (XANES) spectroscopy.

Phosphorus fractions in sandy soils of vineyards in southern Brazil

“…In soils growing annual crops under long-term, successive phosphate applications, organic and inorganic P fractions are accumulated in the soil at different degrees of binding energy, although the accumulation of the inorganic fractions is generally most pronounced (Negassa et al, 2009;Linquist et al, 2011;Tokura et al, 2011). Few studies on P accumulation in vineyard soils after long-term nutrient application have been published in the international literature and none in Brazil.…”

Spectroscopic quantification of soil phosphorus forms by 31p-nmr after nine years of organic or mineral fertilization

“…Phosphorus added by fertilizers is distributed in the soil in inorganic and organic forms, which are subdivided in labile, moderately labile and non-labile forms (Negassa & Leinweber, 2009). This separation depends on the P fractionation method; however, most of these methods provide no information on the structural composition of soil P compounds (Guggenberger et al, 1996).…”

Soil order and management practices control soil phosphorus fractions in managed wetland ecosystems

“…Hedley et al 1982); and land use and management (see review by Negassa and Leinweber 2009). However, there has been limited application of sequential P fractionation applied to lowland rice systems.…”