Pedosphere 5(4): 343--348, 1995
ISSN 1002-0160/CN 32-1315/P
©1995 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Distribution of exchangeable calcium, magnesium and potassium as affected by fertilizer application to red soil |
| SHEN Ren-Fang and ZHAO Qi-Guo |
| Laboratocy of Material Cycling in Pedosphere, Institute of Soil Science, Academia Sintca, P.O. Box 821, Nanjing 210008 (China) |
| ABSTRACT |
| A leaching experiment was carried out with repacked soil columns in laboratory to study the leaching process of a red soil derived from sandstone as affected by various fertilization practices. The treatments were CK (as a control), CaCO3, CaSO4, MgCO3, Ca(H2PO4)2, Urea, KCl, Multiple (a mixture of the above-mentioned fertilizers), and KNO3. The fertilizers were added to the bare surface of the soil columns, and then the columns were leached with 120 mL deionized water daily through peristaltic pumps over a period of 92 days. At the end of leaching process, soils were sampled from different depths of the soil profiles, i.e., 0-5 cm, 5-10 cm, 10-20 cm, 20-40 cm, and 40-60 cm. The results showed when applying Ca, Mg, and K to the bare surface of the soil columns, exchangeable Ca2+, Mg2+, and K+ in the upper layer of the soil profile increased correspondingly, with an extent depending mainly on the application rates of Ca, Mg, and K and showing a downward trend. CaCO3, CaSO4, MgCO3, and Ca(H2PO4)2 treatments had scarcely any effect on movement of exchangeable K+, while CaCO3, and CaSO4 treatments significantly promoted the downward movement of exchangeable Mg2+ although these two treatments had no obvious effect on leaching losses of Mg. The fact that under Urea treatment, exchangeable Ca2+ and Mg2+ were higher as compared to CK treatment showed urea could prevent leaching of exchangeable Ca2+ and Mg2+. The obvious downward movement of exchangeable Ca2+ and Mg2+ was noticed in KCl treatment. In Multiple treatment, the downward movement of exchangeable Ca2+ and Mg2+ was evident, while that of K+ was less evident. Application of KNO3 strongly promoted the downward movement of exchangeable Ca2+ and Mg2+ in the soil profile. |
| Key Words: distribution of exchangeable Ca2+, Mg2+ and k+, fertilization, leaching, red soil |
| Citation: Shen, R. F. and Zhao, Q. G. 1995. Distribution of exchangeable calcium, magnesium and potassium as affected by fertilizer application to red soil. Pedosphere. 5(4): 343-348. |
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