Periphyton: an important regulator in optimizing soil phosphorus bioavailability in paddy fields

Abstract

Periphyton is ubiquitous in paddy field, but its importance in influencing the bioavailability of phosphorus (P) in paddy soil has been rarely recognized. A paddy field was simulated in a greenhouse to investigate how periphyton influences P bioavailability in paddy soil. Results showed that periphyton colonizing on paddy soil greatly reduced P content in paddy floodwater but increased P bioavailability of paddy soil. Specifically, all the contents of water-soluble P (WSP), readily desorbable P (RDP), algal-available P (AAP), and NaHCO 3 -extractable P (Olsen-P) in paddy soil increased to an extent compared to the control (without periphyton) after fertilization. In particular, Olsen-P was the most increased P species, up to 216 mg kg −1 after fertilization, accounting for nearly 60 % of total phosphorus (TP) in soil. The paddy periphyton captured P up to 1.4 mg g −1 with Ca-P as the dominant P fraction and can be a potential crop fertilizer. These findings indicated that the presence of periphyton in paddy field benefited in improving P bioavailability for crops. This study provides valuable insights into the roles of periphyton in P bioavailability and migration in a paddy ecosystem and technical support for P regulation.

Periphyton‐induced changes in the phosphorus sorption characteristics of a paddy soil from coastal mudflat reclamation

“…A fiber substrate was used for periphytic microorganism enrichment and formation (Wu et al, ). First, the substrate was sterilized, rinsed, and submerged into the medium.…”

“…However, the periphyton in artificial wetlands, such as paddy fields, has rarely been investigated. Our previous work indicated that periphyton significantly affects soil P bioavailability in paddy fields (Wu, Liu, Lu, Wu, & Kerr, ). However, the mechanism by which paddy periphyton affects soil P bioavailability remains unclear.…”

Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions

“…For example, when Ca(II) concentration increased from 0 to 1.2 mM, P i concentration in the suspension decreased by 15% to 48%; and when Fe(II) concentration increased from 0 to 0.2 mM, P i concentration in the suspension decreased by 50%. The Ca(II), Fe(II) and P i concentrations chosen in this study are representative of paddy fields (Kögel-Knabner et al, 2010;Wu et al, 2016). Thus, periphyton propagated in paddy fields during the early stage of rice growth would serve as a sink for P i , thereby decreasing loss to surrounding water bodies.…”

Physical geography shapes the distribution characteristics of extracellular polymeric substances in periphytic biofilms

“…stream, wetlands, and rivers, etc.) [6], periphytic biofilms growing in paddy fields are important due to their potential significance for both agronomy and environmental protection [7]. However, the study of periphytic biofilms is still in its infancy due to periphytic biofilms have been chronically ignored by both agronomists and ecologists.…”

“…However, the study of periphytic biofilms is still in its infancy due to periphytic biofilms have been chronically ignored by both agronomists and ecologists. Most of the recent studies on periphytic biofilms have focused on the relationship between their microbial composition and their ecological functions [7,8], while the allimportant abiotic composition of the periphytic biofilm, specifically the EPS component, has received only limited attention.…”