Pedosphere 13(3): 257--262, 2003
ISSN 1002-0160/CN 32-1315/P
©2003 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Interaction of NPK fertilizers during their transformation in soils: Ⅰ. dynamic changes of soil pH |
| WANG Huo-Yan, ZHOU Jian-Min, CHEN Xaio-Qin, LI Shou-Tian, DU Chang-Wen and DONG Cai-Xia |
| Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) |
| ABSTRACT |
| Dynamic changes of soil pH as influenced by ammonium sulfate (AS), monocalcium phosphate (MCP), potassium chloride (KCl) and their interaction in soils were evaluated in incubation experiments. Applying these fertilizers significantly reduced soil pH values in all cases and followed sequences of AS > MCP > KCl, MCP > KCl > AS and KCl > AS > MCP for the paddy, calcareous and red soils, respectively. The AS-induced reduction of pH in the three soils followed the sequence of red soil > paddy soil > calcareous soil, while in MCP and KCl systems the reduction of pH followed the sequences of calcareous soil > paddy soil > red soil and red soil > calcareous soil > paddy soil, respectively. The interactions of the NPK fertilizers on pH were significant. MCP plus KCl or MCP plus AS reduced pH values more than the fertilizers applied solely in the paddy soil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareous soil. The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the red soil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed the reduction of pH at the later incubation stage, which was related to inhibition of nitrification by KCl in the soils. |
| Key Words: nitrogen, pH, phosphorus, potassium |
| Citation: Wang, H. Y., Zhou, J. M., Chen, X. Q., Li, S. T., Du, C. W. and Dong, C. X. 2003. Interaction of NPK fertilizers during their transformation in soils: Ⅰ. dynamic changes of soil pH. Pedosphere. 13(3): 257-262. |
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