1. Phosphorus application promoted the sequestration of orthophosphate within soil microorganisms and regulated the soil solution P supply in a temperate grassland in northern China: A 31P NMR study.
- Author
-
Shi, Jiayu, Gong, Jirui, Li, Xiaobing, Zhang, Zihe, Zhang, Weiyuan, Li, Ying, Song, Liangyuan, Zhang, Siqi, Dong, Jiaojiao, and Baoyin, Taoge-tao
- Subjects
- *
GRASSLAND soils , *TOPSOIL , *SOIL microbiology , *SOIL solutions , *ORTHOPHOSPHATES , *NUCLEAR magnetic resonance , *EXTRACELLULAR enzymes , *PENICILLIUM - Abstract
Anthropogenic activities have made phosphorus (P) a new sustainability issue globally. To better understand the mechanisms of soil P dynamics responding to inorganic P fertilization (0–12.5 g P m−2yr−1), we conducted a 2-year field experiment in a temperate grassland in northern China. The P fertilizer was added once per year before the growth period as NaH 2 PO 4. We randomly collected topsoil samples (0–10 cm) and analyzed the soil properties, microbial community, and extracellular enzyme activities, and quantified the soil P fractions using solution 31P nuclear magnetic resonance (31P NMR) spectroscopy. P application promoted transformation from organic P to inorganic P driven by microbial carbon (C) demand and regulated by altered soil properties and microbial characteristics. P addition decreased orthophosphate diesters, especially DNA, due to increased hydrolysis under increased soil pH. This may increase hydrolysates such as α - glycerophosphate and choline phosphate. Orthophosphate monoesters, especially myo -inositol hexaphosphate, also decreased following increased P availability. This could be explained by increased alkaline phosphatase activity and reduced sorption due to a decreased metal (Ca, Al, and Fe) content. Furthermore, P fertilization increased soil NH 4 +-N, thereby increasing the growth of phosphonate-solubilizing microorganisms (Bacillus, Streptomyces, Bradyrhizobium, Mesorhizobium, Penicillium, Aspergillus , and Fusarium). Their increased growth also contributed to inorganic P solubilization and organic P mineralization due to their P-solubilizing specificity. Together, these factors increased inorganic P, especially orthophosphate, which was temporarily immobilized in microbial cells, to regulate the soil-solution P supply, and created a potentially available P sink in the grassland. • Microbial C demand drove transformations from organic P to inorganic P. • Increased soil pH stimulated the hydrolysis of diesters, especially DNA. • Monoesters decreased due to altered alkaline phosphatase activity and metal content. • Soil NH 4 +-N stimulated the growth of phosphonate-solubilizing microorganisms. • Orthophosphate immobilized in microbes regulated the soil solution's P supply. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF