The efficiency of potassium fertilization methods on the growth of rice (Oryza sativa L.) under salinity stress

Abstract

Land salinization in the coastal region, caused by the progressing of sea or by rising of the saline ground water to the soil surface, is a principal problem in some parts of Iran. It decreases the efficiency of used fertilizers. This study was conducted with the aim of comparing the efficiency of potassium spraying and application in soil; and its effect on yield and yield components of rice under salinity stress in a greenhouse experiment. Treatments included four levels of irrigation water salinity (tap water and salinities 2, 4 and 6 dS/m) and four methods of K application: a, spraying with distilled water as control; b, application of potassium on soil; c, potassium spraying and d, application of potassium on soil plus spraying. Every treatment was replicated three times and study was conducted as a complete randomized block design. The results show that grain yield and shoots, 100 seeds weight, tiller number, root dry weight and potassium uptake in seeds and shoot significantly decreased with increasing salinity. The best method of K application was soil intake plus spraying method.

Key words: Greenhouse, ground water, salinization, spraying.