The effect of different organic fertilizers on salt tolerance of sweet sorghum (Sorghum bicolor (L.) Moench.)

Salinity is one of the most important factors limiting crop production, especially in arid and semi-arid regions of the world. This study has been conducted in order to determine the effects of different organic fertilizers [amino acid (AA), cow manure (CM), biochar (BC), leonardite (LEO), sheep manure (SM), worm manure (WM), poultry manure (PM) and bat guano (BG)] under salt stress (150 mm) conditions in Gulseker sweet sorghum (local variety) cultivar. The trial was carried out according to the randomized split-plot design, in the summer of 2019, under greenhouse conditions. In this research, some morphological (scale, plant height, stem diameter, number of leaves, leaf area, fresh and dry weights, root fresh and dry weights) and physiological parameters [relative water content (RWC), malondialdehyde (MDA), the amount of chlorophyll (SPAD value), sodium (Na+), potassium (K+), calcium (Ca2+) and chlorine (Cl-) ion content) were investigated. As a result of the study, it was found that salt stress caused a decrease in chlorophyll, RWC, K+ and Ca2+ ion content with growth parameters in plants, and an increase in MDA content, Na+ and Cl- accumulation. In additon, compared to salt stress in organic fertilizer applications with salt stress; AA caused improvement of 17.45-221.84%, CM 44.18-441.48%, BC 6.38-260.94%, LEO 9.45-232.58%, SM 31.11-393.21%, WM 7.27-163.20%, PM 36.11-392.46% and BG 14.91-401.81%. As a result, organic fertilizer applications; all of that has a positive impact on the morphological characteristics, additionally, showing a positive effect in reducing the oxidative stress resulting from salt stress level and MDA Cl- and Na+ intake, limiting K+ and Ca2+ uptake to increase, thus resulting from the harmful effects of salt stress applied organic fertilizers, depending on different proportions (6.38-441.48%) had been found to decrease.