| Autor: |
Hosseinpur, Ali Reza, Raisi, Tahereh, Kiani, Shahram, Motaghian, Hamid Reza |
| Předmět: |
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| Zdroj: |
Communications in Soil Science & Plant Analysis; Mar2014, Vol. 45 Issue 6, p726-740, 15p |
| Abstrakt: |
The rate of potassium (K) release from soils can significantly influence K availability to plants. There are few studies about K-release kinetics and K availability in calcareous soils of central Iran. The objective of this study was to study the release rates in 15 different soils from Chaharmahal-Va-Bakhtiari Province through successive extractions with 10 mM citric acid over periods of 2–2016 h and the correlation of K-release characteristics with bean plant indices. The results showed that there was wide variation in the cumulative K release among soils. The cumulative K release ranged from 169 to 1199 mg kg−1. The amounts of K released after 2016 h was not significantly correlated with bean plant indices. Plots of cumulative amounts of K released show a discontinuity in slope at 168 h. Thus, two equations were applied to segments of the total period (2 to 168 and 168 to 2016 h). The amount of K released after 168 h ranged from 62 to 879 mg kg−1. The amount of K released after 168 h was significantly correlated with bean plant indices. In the segment 1 parabolic diffusion, first-order and power function equations and in the second segment parabolic diffusion, first-order, zero-order, and power function equations described K-release kinetics. Release rate constants in the segment 1 were significantly correlated with bean plant indices; however, in the segment 2 release rate constants were not significantly correlated with bean plant indices. The results of our research showed that K-release characteristics after an initial fast reaction play a role in supplying available K and dilute citric acid solution can be used for estimating of K-release kinetics in the studied soils. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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