Multivariate Statistical Analysis of Potassium Status in Agricultural Soils in Hamadan, Western Iran

作者：Jalali M^*

来源：Pedosphere, 2010, 20(3): 293-303.

• adsorption
• Gapon coefficient
• leaching
• non-exchangeable potassium
• principal component analysis

Multivariate statistical technique was used to determine the potassium (K(+)) status and to assess soil fertility and K leaching potential in some calcareous soils. Water-soluble K(+) (H(2)O-K) and ammonium acetate-extractable K(+) (NH(4)OAc-K) ranged from 0.019 to 0.590 (mean value 0.095) and 0.390 to 3.320 (mean value 0.954) cmol(c) kg(-1), respectively. The nitric acid-extractable K(+) (HNO(3)-K) varied from 1.03 to 13.63 (mean value 5.37) cmolc kg(-1). The proportion of H(2)O-K ranged from 0.34% to 14.8% of HNO(3)-K, and 2.2% to 53.2% of NH(4)OAc-K. The proportion of NH(4)OAc-K ranged from 5.8% to 80% of HNO(3)-K (mean value 23% of HNO(3)-K). The tendency of the soil to lose K(+) by leaching was examined by determining K(+)-Ca(2+) exchange isotherms. The soils mostly had moderate to high values of K(+) sorption capacity, ranging from 10% to 58% (mean value 28%) of added K(+). The Capon coefficient varied widely from 1.1 to 12.0 (L mol(-1))(-1/2). Clay minerals were dominated by illite, smectites and vermiculite with small amounts of kaolinite. Principal component analysis (PCA) showed that the first four components accounted for 27.7%, 21.4%, 13.8%, and 8.9% of total variation, respectively. The non-hierarchical cluster analysis (k-means clustering) grouped 75 sampling sites into six clusters, based on the similarity of soil quality characteristics The results suggested that such classes could form a basis for variable-rate application to maintain an adequate K(+) status for crop production and to reduce potential K(+) loss from soil by leaching.

• 出版日期2010-6