The effect of different organic matters on plant growth regulation and nutritional components under salt stress in sweet sorghum [Sorghum bicolor (L.) Moench.]

Salinity is one of the major constraints of crop production, especially in the world's arid and semi-arid regions. Variations in the nutritional components of Gulseker sweet sorghum (local variety) and the effects of different organic matter on morphological and physiological changes under salt stress were examined herein. The response of sweet sorghum to applications of different organic matter [amino acid (AA), cow/farmyard manure (CM), biochar (BC), humic acid (HA), sheep manure (SM), worm casting (WC), poultry manure (PM), and bat guano (BG)], as well as water irrigation salinity at 150 mM NaCl were evaluated under greenhouse conditions using plastic pots containing 11 L of peat:perlite (2:1). Plants grown under different treatments were then classified as morphological (shoot fresh and dry weights, shoot diameter, shoot length, number of leaves and leaf area per plant) and physiological parameters (relative water content (RWC), chlorophyll (SPAD), malondialdehyde (MDA), Na+, K+, Ca++, and Cl- ion content. The results revealed that salt stress caused reduced growth parameters and chlorophyll, RWC, K+ and Ca++ ion content, while MDA content, Na+ and Cl- accumulation showed an increase. The results showed that the organic matter treatments diminished the damaging effects caused by salt stress via a reduction in the uptake of Cl- and Na+, which enhanced K+ and Ca++ uptake and reduced the MDA levels, presenting a favorable effect in reducing the oxidative stress that emerged from salt stress.