Cai Guan, Hu Ya-Jun, Wang Ting-Ting, Yuan Hong-Zhao, Wang Jiu-Rong, Li Qiao-Yun, Ge Ti-da, Wu Jin-Shui
College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.
Public Service Technology Center, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
Huan Jing Ke Xue. 2017 Apr 8;38(4):1606-1612. doi: 10.13227/j.hjkx.201608178.
A suitable fractionation method of phosphorus (P) is a key to effective assessment of soil P componential features. Here a new biologically-based P (BBP) method was used to evaluate the P fractions in the upland and paddy soils across large-scale area in China. The soil P was divided into four components:① soluble or rhizosphere-intercepted (CaCl-P), ② organic acid activated and inorganic weakly bound (Citrate-P), ③ enzyme mineralization of organic P (Enzyme-P), ④ potential activation of inorganic P (HCl-P). Then, the relationships between biologically-based P fractions and standard Olsen-P were investigated, and driving factors of P fractions were identified. The results showed that P content was in order of HCl-P>Citrate-P>Enzyme-P>CaCl-P. All P components of upland soil displayed higher levels than those of paddy soil. Moreover, the P components were highly positively correlated with the Olsen-P, suggesting that each P component contributed to soil P availability. However, it was found that Olsen-P was most highly correlated with CaCl-P and Enzyme-P (=0.359; =0.386) in upland soil, while Olsen-P was most highly with Citrate-P (=0.788) in paddy soil. This result indicated that available P of upland soil was mainly from organic P mineralization and soluble P, and available P in paddy soil was mainly from inorganic P activation. Redundancy analysis (RDA) showed that the P components were mainly affected by soil pH and silt content, which suggested that it could enhance the P availability via regulating soil pH in the agricultural activities.
