Pedosphere 18(4): 533--538, 2008
ISSN 1002-0160/CN 32-1315/P
©2008 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Enhancement of phosphorus solubility by humic substances in Ferrosols |
HUA Quan-Xian1,2 , LI Jian-Yun3, ZHOU Jian-Min2, WANG Huo-Yan2, DU Chang-Wen2 and CHEN Xiao-Qin2 |
1 Zhengzhou University, Zhengzhou 450001 (China);
2 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China);
3 Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou 450015 (China) |
| ABSTRACT |
| An investigation was conducted to study the effect of humic substance (HS) on the phosphorus (P) solubility in acidic soil. The soil (2.5 g), HS (0, 0.5, and 2.5 g), and P as monocalcium phosphate (0.31 and 1.25 g P kg-1 soil) were mixed with 50 mL distilled water and two different sequences of adding HS and P were used. The results indicated that the P concentration in water and 0.01 mol L-1 CaCl2 solution increased with increasing amounts of humic substance. The concentrations of Fe and Al were also increased. However, Olsen P decreased with increasing amount of humic substance. Water-soluble P concentrations from P rates at 0.31 and 1.25 g P kg-1 soil in the treatment with 0.5 g (2.5 g) humic substance addition were 360% and 70% (500% and 90%) higher, respectively, than those in the treatment with no humic substance addition. P extracted by 0.01 mol L-1 CaCl2 in the treatments with 0.5 and 2.5 g humic substance addition was increased by 400% and 540%, respectively, compared with that in the treatment without humic substance at the rate of 0.31 g P kg-1 soil, while the corresponding P concentrations were increased by 80% and 90% at the rate of 1.25 g P kg-1 soil. The order of mixing humic substance and phosphate did not significantly affect desorbed P and labile P extracted with CaCl2. |
| Key Words: aluminium, Ferrosols, humic substance, iron, phosphorus |
| Citation: Hua, Q. X., Li, J. Y., Zhou, J. M., Wang, H. Y., Du, C. W. and Chen, X. Q. 2008. Enhancement of phosphorus solubility by humic substances in Ferrosols. Pedosphere. 18(4): 533-538. |
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