The potential of silicate fertilizer for salinity stress alleviation on red rice (Oryza sativa L. 'Sembada Merah')

Climate change causes an increase in soil salinity, hence reduce rice growth and productivity. The application of silicate fertilizer as a source of silicon (Si) can be encouraged to enhance the rice tolerance against biotic and abiotic stresses. This study aimed to analyze the potential of silicate fertilizer to alleviate the salinity stress on red rice. A pot experiments was conducted to observe the physiological and biochemical aspects. Rice seedlings were treated with three doses of rice husk ash/ RHA (0, 4, and 8 tons ha(-1)), and three levels of salinity stress, namely control (0 dS m(-1)), low (3 dS m(-1)), moderate (7 dS m(-1)), and high (10 dS m(-1)). The observed parameters were plant height, number of tillers, plant biomass, activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT), levels of chlorophyll, carotenoid and proline. The results showed the growth of red rice 'Sembada Merah' was inhibited by moderate and high salinity stress as indicated by a decrease in plant height, number of tillers and plant biomass. Photosynthetic pigment chlorophyll and carotenoid levels decreased with the increasing salinity stress. RHA application increased SOD activity as a response to enhance salinity stress tolerance. At doses of 4 t ha(-1), RHA could maintain rice growth up to moderate salinity stress.