Drought Tolerance

Kelp and Humic Acid For Heat Stress

Boosting soil & crop tolerance to drought.

Improving Drought Resistance with Humic Acid and Kelp

Humic Acid - aids moisture management

Kelp- better root growth for resilience

Humic Acid

Humic acid is a highly concentrated form of the most active part of soil humus (carbon). It is extremely cost-effective from only a few dollars per hectare.

Humic acid improves drought resistance by improving moisture retention and soil structure, as well as the water content of leaves.

Specifically, Humic Acid improves drought resistance by:

  • Improving moisture holding capacity of most soils. Humic acid is concentrated humus which holds seven times its own weight/volume in water, compared to humus in soil and compost which hold their own weight.
  • Improving soil structure like no other input can. Humic acid modifies the permeability, porosity, water retaining capacity, absorption characteristics, surface area and cation exchange reactions. In sandy soils, humic acid provides a charged surface to hold onto moisture. In clay, humates penetrate clay particles and prevent them sticking together. This keeps clay particles apart so the water can easily penetrate. (Karr 2001)
  • Working at the cellular level. Plants subjected to drought stress showed the capacity to osmotic adjust by maintaining water absorption and cell turgor in response to humic acid. Humic acids also stimulate enzymatic and non-enzymatic antioxidant defence systems during drought stress. (Canellas 2015)
  • Increasing the water content of leaves. For example common beans had significantly higher water content with humic acids and bacteria during water stress and after recovery - Canellas 2015. Multiple studies show drought stressed crops suffer less with humates. (Karr 2001, Celik 2011, Piccolo 1997, Imbufe 2005)


Kelp improves root growth and resilience during dry periods. Kelp improves drought tolerance by:

  • Enhanced water uptake by the plant as a direct result of increased root growth (Khan 2009).
  • Stimulating changes in the plant’s metabolic pathways, allowing roots access to moisture not normally available to plants. Even under moisture stress conditions, the use of kelp has been shown to stimulate root growth. (Khan 2009).
  • Cytokinins in kelp slowing the rate of the plant’s degradation processes and stimulating photosynthetic activity. (Ervin 2004)
  • Cytokinins & Betaines in kelp increasing turgidity of cell walls so water is less likely to flow out of cells. (Khan 2009)
  • Increasing chlorophyll by improving photosynthesis (Blunden 1997)
  • Improving the moisture-holding capacity and promoting the growth of beneficial soil microbes - alginates in Kelp involved. (Khan 2009)
  • Enhancing Potassium uptake which also induces heat tolerance. (Ervin 2004)