Rice response to different methods of potassium fertilization in salinity stress condition

ABSTRACT: Salinity is an environmental stress that limits growth and development in plants. With appropriate fertilizers application methods on salinity conditions can reduce its harmful effects and increased productivity of salinized soils. A pot experiment was carried out in 2011 in rice research institute of Iran to examine the effects of potassium application methods on the response of rice (Oryzae Sativa L.) to different soil salinity levels. Four methods of potassium 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 and four levels of irrigation water salinity (tap water and salinities 2, 4 and 6 dsm-1) were investigated in complete randomized block design with three replications. Results showed that soil salinity affected growth and yield component parameters in most of the cases. Potassium application alleviated the stress condition and significantly improved dry matter yield and yield components in rice. Grain, straw, total biological yield, harvest index, 100 seeds weigh ,root dry weigh and total tillers significantly decreased with increasing salinity but grain protein increased with increasing salinity. The interaction between salinity levels and methods of potassium application was significant only for root dry weight.