Pedosphere 2(3): 201--208, 1992
ISSN 1002-0160/CN 32-1315/P
©1992 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Kinetics of K Desorption from Soils in a Constant Electric Field (Electro-Ultrafiltration) and Its Application |
| LU XIAO-NAN, LU YUN-FU |
| Institute of Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021 |
| ABSTRACT |
| Kdesorption from soils in a constant electric field (field strength:44.5Vcm-1) by means of electro-ultrafil-tration (EUF) followed second-order kinetics and could be described by the equation dd/dt=k(D-d)2. From theequation, such kinetic parameters relating to K desorption from soils as the maximum desorbable quantity D, quantity of K desorbed within 40 minutes d40, initial desorption rate Vo, desorption rate constant k and half-time t1/2 could be calculated. An expression which describes the relationships between the kinetic parameters on the one hand and the responses of barley to fertilizer-K in the field experiments in different sites and the potassium-supplying power of soils on the other was established. Vo, D and d40 were significantly correlated with barley relative yield, K uptake by barley and the content of soil available potassium. The rate constants of K desorption varied between 4.42×10-4-1.80×10-3kg mg-1 min-1 and highly correlated with the relative yield of barley. |
| Key Words: |
| Citation: Lu, X. N. and Lu, Y. F. 1992. Kinetics of K Desorption from Soils in a Constant Electric Field (Electro-Ultrafiltration) and Its Application. Pedosphere. 2(3): 201-208. |
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