1. Aerts, R., Chapin, F.S., 2000. The mineral nutrition of wild plants revisited: a re-evaluation of processes and patterns. Adv. Ecol. Res., 30:1–67. [doi:10.1016/S0065-2504(08)60016-1]
2. Ashraf, M., Naz, F., 1994. Responses of some arid zone grasses to K-deficiency. Acta Physiol. Plant, 16:69–80.
3. Bao, S.D., 2005. Soil and Agricultural Chemistry Analysis. China Agriculture Press, Beijing, China, p.106–268 (in Chinese).
4. Basile, B., Reidel, E.J., Weinbaum, S.A., DeJong, T.M., 2003. Leaf potassium concentration, CO2 exchange and light interception in almond trees (Prunus dulcis (Mill) D.A. Webb). Sci. Hortic.-AMSTERDAM, 98(2):185–194. [doi:10.1016/S0304-4238(02)00214-5]
5. Beauchamp, C., Fridovich, I., 1971. Superoxide dismutase: improved assays and an assay applicable to acrylamide gels. Anal. Biochem., 44(1):276–287. [doi:10.1016/0003-2697(71)90370-8]