Details

Autor(en) / Beteiligte

• Najafi-Ghiri, Mahdi
• Boostani, Hamid Reza
• Hardie, Ailsa G.

Titel

Release of potassium from some heated calcareous soils to different solutions

Ist Teil von

• Archiv für Acker- und Pflanzenbau und Bodenkunde, 2023-01, Vol.69 (1), p.90-103

Ort / Verlag

Abingdon: Taylor & Francis

Erscheinungsjahr

2023

Quelle

Taylor & Francis

Beschreibungen/Notizen

• Top soil burning may occur in shifting cultivation in hills, forest fire or burning of agricultural straw. It may affect the mechanisms of potassium (K) release by different extractants. Cumulative K release from six calcareous soils before and after heating (at 350°C) during 10 times extraction with 0.025 M CaCl 2 , HCl, oxalic and citric acids was determined. Initial K release was increased from 8-23 mg kg −1 to 13-47 mg kg −1 by heating the soils. Citric acid extracted more K than other solutions in the initial stage of K release. Cumulative K release ranged from 61 mg kg −1 for Torriorthents (containing high calcium carbonate and low clay) to 248 mg kg −1 for Haploxererts (containing low calcium carbonate and high illitic clay). Citric and oxalic acids extracted more K than CaCl 2 and HCl. Heated soils released more K than unheated soils to the different extractants (62, 86, 112 and 105% increase for CaCl 2 , HCl, oxalic and citric acids, respectively). It is concluded that presence of calcium carbonate in soil affects the mechanisms of K release; in highly calcareous soils, exchange reactions were the main mechanism, while in slightly calcareous soils, exchange reactions and mineral dissolution were involved in the K release.