Periphyton has the potential to increase phosphorus use efficiency in paddy fields

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Phosphorus (P) supply often mismatches rice demand, causing low P use efficiency and environmental risks.
• Periphyton's role in regulating paddy field nutrients is gaining attention, but its impact on P cycling needs mechanistic understanding.

Purpose of the Study:

• To investigate how periphyton proliferation and decomposition affect phosphorus migration and bioavailability in paddy soils.
• To understand periphyton's influence on P biogeochemical cycling during critical rice growth stages.

Main Methods:

• Two microcosm experiments were conducted using two different paddy soils.
• The study examined periphyton's influence on the soil surface and its decomposition effects on P.

Main Results:

• Periphyton proliferation on the soil surface under light conditions accumulated fertilizer P, reducing P fixation and runoff.
• Periphyton decomposition under dark conditions increased soil soluble reactive P and labile P fractions (AlP, FeP, OP).

Conclusions:

• Periphyton acts as a P sink in early rice growth, mitigating environmental risks.
• Periphyton decomposition in later stages serves as a P source, enhancing P bioavailability for rice.
• Regulated P bioavailability by periphyton can align with rice nutrient needs, potentially increasing P use efficiency.