Potassium fertilization: paradox or K management dilemma?

作者：Bar Yosef B; Magen H^*; Johnston A E; Kirkby E A

来源：Renewable Agriculture and Food Systems, 2015, 30(2): 115-119.

DOI：10.1017/S1742170514000295

• exchangeable potassium
• capacity/intensity
• chloride
• potassium fertilizer recommendations
• non-exchangeable potassium

In 2014, Khan et al. presented evidence that soil exchangeable K (Exch-K) increases over time without addition of potassium (K) to the soil despite the removal of K in crops on a soil rich in montmorillonite and illite. The authors term this behavior 'The potassium paradox'. From their review of the literature, the authors also report a lack of crop response to potassium chloride (KCl) fertilization. Close evaluation of these findings reveals that their observations can be interpreted and predicted using current knowledge of K in soil chemistry and its uptake by plants, and there is no paradox in K behavior in the soil-plant system. There is also no evidence of a detrimental effect of KCl on crop yield or quality. Their conclusion that the widely used Exch-K soil test is inadequate for managingKfertilization is discussed and some possible modifications to improve its performance are included. We believe that measurement of Exch-K is an essential and valuable tool and its use should be continued, along with improvements in recommending K fertilizer application.

• 出版日期2015-4