Phosphorus Sorption and Redistribution on Soil Solid Phase in a Brazilian Haplorthox Amended with Biosolids

Abstract

Land application of biosolids (SS) can cause a buildup of phosphorus (P) in the top soil. The changes in the soil P characteristics may be assessed by the sorption isotherm and the sequential fractionation techniques. Samples of Haplorthox were collected from a field experiment where maize was cultivated for two years, after two applications of SS originated from two cities of São Paulo State, Brazil. SS applications added a total of 125, 250, 500, 1000 and 2000 kg ha−1of P in the area. To perform the sorption isotherms and obtain P maximum sorption capacity (Qmax) and the binding energy, soil samples were submitted to increasing P concentration solutions until equilibrium was reached. Sequential fractionation was done by a sequential extraction with CaCl2, NaHCO3, NaOH, HCl, and HNO3+ HClO4(residual). Addition of biosolids from both cities to the soil decreasedQmaxand the binding energy obtained by the Langmuir equation. SS additions changed the P fractions distribution in the soil by increasing the labile fractions (P-CaCl2and P-NaHCO3) and the moderately labile fraction (P-NaOH) by 11.2% and 20.3%, respectively, in detriment of the most resistant P fraction.

Phosphorus sorption on tropical soils with relevance to Earth system model needs

“…Our Langmuir-calculated P sorption maxima exceeded many of the Qmax values used by Yang et al (2014) in their ESM (Anghinoni et al 1996;Gichangi et al 2008;Bastounopoulou et al 2011;Munhoz et al 2011;Wang and Liang 2014). These studies also used notably different maximum P concentrations to calculate the P sorption isotherm, which could lead to an underestimation of P Qmax values (Harter 1984).…”

“…Oxisols and Andisols (Wang et al 2007;Goll et al 2012;Yang et al 2014;Yang et al 2016). However, there is a lack of P sorption studies related to tropical soils (Fontes and Weed 1996;Sato and Comerford 2005;Munhoz et al 2011) compared with other environments (Anghinoni et al 1996;Gichangi et al 2008;Cannon 2010;Bastounopoulou et al 2011).…”

“…Tropical soils are particularly prone to this potential source of error due to their high P sorption capacities (Walker and Syers 1976;Fontes and Weed 1996;Poudel and West 1999;Elser et al 2007;Auxtero et al 2008;Yang et al 2014;de Campos et al 2016). Further, there is an absence of reported parameter uncertainties in the current literature, such as standard error or confidence intervals (Ryden et al 1977;Fox 1982;Anghinoni et al 1996;Fontes and Weed 1996;Gichangi et al 2008;Bastounopoulou et al 2011;Munhoz et al 2011). Without these uncertainty values, it is difficult to compare sorption parameters from different studies in the same context.…”

“…Without these uncertainty values, it is difficult to compare sorption parameters from different studies in the same context. Finally, sorption isotherms are often fitted to the Hanes-Woolf linearised form of the Langmuir equation (Ryden et al 1977;Fox 1982;Anghinoni et al 1996;Fontes and Weed 1996;Gichangi et al 2008;Bastounopoulou et al 2011;Munhoz et al 2011). The axes of a linearised isotherm are not truly independent of one another because the sorbed concentration (y-axis) is calculated from the equilibrium solute concentration (x-axis).…”

Fertilidade e disponibilidade de fósforo em Latossolo tratado com lodo de esgoto

“…até 720 kg ha -1 P2O5 e 15 cultivos sucessivos, observou que até o cultivo 9, as formas de P mais recalcitrantes (PiHID05, PoHID05, PRES) não foram modificadas expressivamente, refletindo pouca participação destas frações quando a disponibilidade das mais lábeis era maior. A partir do cultivo 9, ouve mineralização das frações orgânicas recalcitrantes, o que contribuiu para a disponibilização do nutrientes para os cultivos subsequentes.Foi possível observar que a aplicação de LE modificou alguns aspectos na dinâmica do P nos solo, pois além de formar compostos de maior ou menor complexidade, ligados a Fe, Al, Ca e matéria orgânica,(RAIJ, 2004;MUNHOZ; BERTON, 2006), altera a sua disponibilidade e redistribui o elemento entre as suas principais frações no solo. A proposta de que a aplicação de LE aumenta as frações lábeis de P no solo, aumentando a disponibilidade do nutriente para as plantas, foi aqui comprovada pela evidencia de aumento da fração lábil nas três profundidades estudadas.…”