Integrative Potassium Humate and Biochar Application Reduces Salinity Effects and Contaminants, And Improves Growth and Yield of Eggplant Grown Under Saline Conditions

Abstract

In agriculture sector, soil salinity is one of the major problems that limit plant performance, particularly in arid and semiarid regions, including Egypt. The effect of potassium humate (KH) and casuarina biochar (Bch), applied singly or in integration, on plant performance, physio-biochemical attributes and antioxidant, and contents of contaminants of Solanum melongena plants grown under salt stress (EC = 6.96 – 7.08 dS m?1 ) was investigated. Results showed that, soil treatment with KH significantly improved plant growth and productivity, physio-biochemical attributes, and contents of K+ , osmoprotectants and antioxidants (soluble sugars, proline and ascorbic acid), and significantly lowered plant contents of contaminants (NO3 ? , NO2 ? and Cd2+) and Na+ ion compared to the untreated controls. The same results trend was obtained with soil treatment with Bch. Integrative application of KH + Bch was most effective compared to the single KH or Bch treatment. The above results recommended benefits of the integrative treatment KH+TOC to soil for the possibility of sustainable agronomic performance of eggplant grown on saline soils.