Priming and Coating Seeds with Humic Acid as an Effective Strategy in the Integrated Management of Salt-Affected Soils

Atefeh Rashidifard

Objective: Salinity is a major abiotic stress reducing crop yield and quality worldwide. This review systematically evaluates the effectiveness of seed priming and coating with humic acid (HA) as a strategy to improve germination, seedling establishment, and plant growth under salt stress.
Method: A comprehensive literature search was conducted in major scientific databases (Web of Science, Scopus, Google Scholar) using relevant keywords. Studies investigating physiological, biochemical, and molecular mechanisms of HA-mediated salt tolerance through seed priming and coating were reviewed.
Results: Seed priming and coating with humic acid significantly improved germination percentage and rate, increased root and shoot growth, and enhanced chlorophyll content and photosynthetic efficiency under salinity. HA reduced Na⁺accumulation, improved K⁺/Na⁺ ratio, and increased activity of antioxidant enzymes (SOD, CAT, POX). It also promoted ATP production and facilitated uptake of essential nutrients (K⁺, Ca²⁺, Mg²⁺).
Conclusions: Seed priming and coating with humic acid is an effective, low-cost, and environmentally friendly approach to enhance salt tolerance in crops. It accelerates seedling establishment, stimulates root growth, and reduces oxidative stress by boosting antioxidant enzyme activity. Future research should focus on synergistic effects with other biostimulants across different crops and salinity levels.

Highlights

Priming and coating seeds with humic acid boosts plant tolerance to salinity stress.
Humic acid improves soil health and nutrient efficiency sustainably.
Priming and coating seeds with humic acid is a cost-effective method for boosting crop growth and yield in salt-affected soils.

Iranian Journal of Seed Research

Priming and Coating Seeds with Humic Acid as an Effective Strategy in the Integrated Management of Salt-Affected Soils