RT - Journal Article T1 - Potassium Fixation and its Relationship with Physico-Chemical Properties and Clay Minerals in the Calcareous Soils of Kakan Plain, Kohgilouye & Boyerahmad Province JF - JSTNAR YR - 2018 JO - JSTNAR VO - 22 IS - 1 UR - http://jstnar.iut.ac.ir/article-1-3376-en.html SP - 239 EP - 254 K1 - Smectite K1 - Potassium fixation K1 - Drying and wetting K1 - Organic carbon K1 - Kakan plain. AB - Potassium fixation is one of the most important factors influencing the availability of this ion for plants. This research was carried out to evaluate the relationship between potassium (K) fixation with some physical and chemical characteristics of soils and clay minerals and to investigate the effect of the dry and wet cycle on potassium fixation in Kakan Plain, in Kohgilouye & Boyerahmad Province. To measure the amount of Potassium fixation, four levels of K were added to the samples and the samples were shaken for 24 h and then dried in the oven at 50°C for 24 h. The drying and wetting cycle was repeated three times. Another set of soil samples was similarly incubated for a period similar to the previous treatment, but drying was performed at room temperature in an equilibrium state. The results showed that potassium fixation was increased with the potassium concentration increment, whereas K fixation percentage was reduced. Also, potassium fixation showed a positive significant relationship with cation exchange capacity (CEC) as well as clay content, in both normal and dry and wet treatments, and a negative significant relationship with organic carbon. Moreover, potassium fixation was enhanced with the increase of smectite content in both normal and dry and wet treatments. Besides, due to more organic carbon and less smectite, surface horizons fixed K less than the subsurface horizons. LA eng UL http://jstnar.iut.ac.ir/article-1-3376-en.html M3 10.29252/jstnar.22.1.239 ER -