Potassium behavior and clay mineral composition in the soil with low effectiveness of potassium application

作者：Kubo Katashi; Hirayama Takashi; Fujimura Shigeto; Eguchi Tetsuya^*; Nihei Naoto; Hamamoto Shoichiro; Takeuchi Megumi; Saito Takashi; Ota Takeshi; Shinano Takuro

来源：Soil Science and Plant Nutrition, 2018, 64(2): 265-271.

DOI：10.1080/00380768.2017.1419830

• Buckwheat
• clay mineral composition
• exchangeable potassium
• potassium fixation
• vermiculite

Increasing exchangeable potassium (ExK) content in soil to an appropriate level is important to mitigate the transfer of radioactive cesium to crops. We focused on a buckwheat (Fagopyrum esculentum Moench) field with a low ExK content, despite the application of K, in Fukushima Prefecture, Japan (Field A), following the Tokyo Electric Power Company Fukushima Dai-ichi (No. 1) Nuclear Power Plant accident in March 2011. We examined the relationship between K concentration and clay mineral composition in the soil of Field A and compared the findings with another field in Fukushima Prefecture (Field B) to clarify whether K applied to the soil was leached or remaining fixed. Pot experiments showed that K concentration in water seepage from pots following irrigation was significantly lower in pots from Field A than in those from Field B. Soil ExK content after soybean cultivation was lower in soils of Field A than those of Field B. These results indicate that K applied to Field A was fixed in the soil. Analysis of clay mineral composition confirmed the distinctive vermiculitic nature of Field A soils. This clay mineralogy would be associated with the higher K fixation ability of Field A than Field B soils. This study demonstrated that K fixation in vermiculite was a factor preventing the increase in ExK content from K application to Field A.

• 出版日期2018