Phosphorus status and its sorption-associated soil properties in a paddy soil as affected by organic amendments

Abstract

Purpose Yet the transformation and contribution of amorphous aluminum and iron which are usually indicated as oxalateextractable forms (Al ox and Fe ox ) to phosphorus (P) sorption in paddy soils, under long-term organic amendments combined with alternating flooding and draining, were not fully understood. The aim of this study was to investigate the effects of organic amendments on P status and P sorption-associated attributes including Al ox and Fe ox in a paddy soil. Materials and methods We selected 26 study sites that varied in three fertilization regimes (i.e., MF, straw, and manure) and three management histories (i.e., 2, 8, and 13 years) in the experiment station. Soil samples were assayed for (1) P accumulation status including total P, Olsen-P, oxalate-extractable (P ox ) and degree of soil saturation with P (DPS), and (2) soil properties associated with P sorption including pH, soil organic matter (SOM), Al ox , and Fe ox . Results and discussion Manure application presented significantly greater values for DPS (16.3 %, P<0.01), Olsen-P/TP ratio (4 %, P<0.01), and Olsen-P/P ox ratio (6.8 %, P<0.01). Moreover, it increased the contents of Al ox and Fe ox in the paddy soil, especially the content of Al ox . Phosphorus accumulation in the paddy soil was not significant in straw treatment vs. MF treatment. Both Al ox (P<0.01) and Fe ox (P<0.05) exhibited significantly linear relationships with SOM, suggesting that the organo-Al(Fe) complexes might widely generate in the paddy soil, which have strong affinity to P. In comparison with Fe ox , Al ox showed greater correlation coefficients with soil P forms (varying from 0.56 to 0.81) and higher predictability for DPS of the paddy soil (R 2 =0.3679, P<0.01). Conclusions These results suggest that Al ox is the primary soil property associated with P sorption in the paddy soil under long-term organic amendments and repeated redox circulations.

Relation between various soil phosphorus extraction methods and sorption parameters in calcareous soils with different texture

“…P CaCl2 , P citrate , P HCl , P Ols , and P M3 were highly correlated with TP (r = 0.587, 0.393, 0.886, 0.655, and 0.763, respectively). Similar results were also found by Palmer-Felgate et al (2009), Yan et al (2013), and Yan et al (2015). Pizzeghello et al (2011) suggested that the different correlations obtained can be related to the ability of methods to extract different proportion of available P. It was suggested that the buffering capacity and affinity of P in noncalcareous soils was strongly associated with extractable Al (Daly et al, 2015), while in calcareous soils it may be associated with extractable Ca (McLaren et al, 2014).…”

Organic Fertilization Improves the Availability and Adsorptive Capacity of Phosphorus in Saline-Alkaline Soils

“…Soil adsorption capacity could effectively inhibit the release of P into water (Cui et al 2017). On the one hand, the soil adsorption capacity of P is influenced by the presence of ions, such as amorphous Fe and Al minerals (Yan et al 2013;Yan et al 2015;Fei et al 2019). In fact, Kang et al (2009) and Yan et al (2017) indicated that the mechanism involving the increase of P adsorption in soils included the stable complexes formed between P and amorphous Fe and Al minerals.…”

Effects of drying and simulated flooding on soil phosphorus dynamics from two contrasting UK grassland soils

“…Iron (Fe 3+ ) is redox sensitive and reduces to Fe 2+ with the development of reducing conditions, subsequently releasing previously sorbed P into soil solution. Phosphorus release as a result of reductive dissolution of P bearing minerals has been reported in studies on flooded soils from wetlands (Lai & Lam, 2008;Liu et al, 2012;Maranguit et al, 2017), paddy soils (Li et al, 2017;Rakotoson et al, 2016;Yan et al, 2015) and floodplains (Loeb et al, 2008;Schonbrunner et al, 2012). Although Al is not redox sensitive, flooding-induced increase in pH can solubilise Al-organic matter-PO 4 (Al-OM-PO 4 ) complexes (Darke & Walbridge, 2000).…”

“…Bai et al, 2017;Kumaragamage et al, 2020;Rapin et al, 2019;Shaheen et al, 2021). However, studies investigating the effect of flooding on P dynamics are mainly confined to paddy soils (Li et al, 2017;Yan et al, 2015), wetlands (Bai et al, 2017;Lai & Lam, 2008;Surridge et al, 2007) and floodplains (Loeb et al, 2008;Schonbrunner et al, 2012) where soils remain flooded for large parts of the year and therefore are likely to have microbial populations well adapted to the seasonal fluctuations in soil moisture content. Moreover, in soils experiencing repeated drying-wetting/flooding cycles aggregates may become slake resistant (Denef et al, 2001), thus lowering the risk of nutrient release due to breakdown of aggregates and exposure of new labile organic matter (OM).…”

“…Despite the large number of studies on paddy soils (e.g. Li et al, 2017;Yan et al, 2015) and the influence of soil drying-rewetting on P mobilisation (e.g. Blackwell et al, 2013;Forber et al, 2017;Homberg & Matzner, 2018), it is unclear to what extent flooding of dried soils would influence soil-P mobilisation compared to flooding of soils which have not been dried.…”