Kelp Help

kelpMountains and land masses are born from the ocean in massive geological upheavals called diastrophism. Then, in nature’s typical cyclical fashion, the process of erosion through wind and rain ensures the gradual return of minerals and topsoil in a relentless flow back to the ocean. Many of the seventy (+) minerals that were present in the first cell that developed in the Precambrian Ocean, are no longer present in our soils. The ocean, however, retains this mineral motherlode and creatures and plant life which live within this elemental soup contain the broad-spectrum minerals so lacking on land! Ironically, this sea life has access to more than the smorgasbord of minerals eroded over the eons. It also enjoys a literal flood of mineral nutrients that are leached and eroded from our agricultural and garden soils, due to the overuse of soluble fertilisers and poor soil management practices.
And so the land rises from the ocean and gradually returns as part of a grand billion-year recycling plan. The most important facet of ‘working with nature’ is learning from her. If the cyclical pattern is ocean to earth – earth to ocean, then our lesson is to continue this recycling pattern and to return the essence of the sea back to the land. The minerals we have lost are encapsulated within a harvestable commodity in the ocean, and their recycling should be our urgent priority. Kelp and fish-based fertilisers are an invaluable tool for the remineralisation of our croplands.


Kelp is a marine algae. Although it is a plant, it has few of the structural characteristics of the land-dwellers. It does, however, possess a leaf-like structure, called a blade, which photosynthesises, using sunlight filtered from above. A stem-like structure, called a stipe, supports the blade, but there is no need for a root system, as minerals are in plentiful supply in the aquatic atmosphere. A base support system, consisting of a frond is attached to holdfasts to form a gripping mechanism, which anchors the algae in place. Kelp is a direct or indirect food source for a large sector of sea life, and it is also consistently eroded by tides. The secret of survival in these tough conditions is extremely rapid growth.

Some varieties of kelp can grow as much as 30 cm per day, and this phenomenal growth is partially fuelled by a series of naturally occurring organic growth compounds. The most notable of these are cytokinins, which are found in kelp at much higher concentrations than in any other plant. All plants produce cytokinins for their own growth promotion and consequently they will also respond to this organic growth compound from other sources. The plant growth promoting potential of kelp has been recognised for centuries. The ancient Greeks fertilised with kelp and the Chinese have enriched their coastal soils with seaweed for centuries. The value of cultivated, managed and ocean-harvested seaweed currently exceeds twelve billion Australian dollars. It is a major nutrient source for humans throughout the world, but food and industrial use account for the majority of total useage. Agriculture currently uses just forty million of this total (less than 0.35%), and this reflects a poor general understanding of the numerous benefits attributed to this ‘wonder-weed’.


Most of the early US research into kelp was conducted at Clemson University, by Dr T L Senn and his team from 1959 to 1975. Meanwhile, English academic, Dr Gerald Blunden was making his own discoveries about the mechanics of the kelp response. Blunden embarked on his research with the sole intent to prove once and for all that kelp was a ‘snake oil’. To his amazement, he found compelling evidence to support many of the seaweed claims, and he was eventually instrumental in documenting the organic growth compound link to many of the kelp benefits.


Kelp contains gibberellins, auxins, betaines and cytokinins. The auxin content is relatively low, and the levels of gibberellins and betaines found in the plant are not exceptional. Dr Blunden was unable to identify any significant response from these three hormones during his research, and he attributed this to their inherent instability, perhaps related to the rigours of the extraction process, combined with suspect shelf-life during storage. Subsequent researchers, however, have been able to identify specific gibberellin and auxin responses associated with kelp treatment. Blunden believed that cytokinins, however, are the key players when evaluating kelp response. Seaweed contains very high levels of organic growth compounds, and it remains stable throughout the extraction and storage stages.
Cytokinins are responsible for cell division, cell enlargement, the development/stability of chloroplasts and delayed senescence (an extended crop cycle). Dr Blunden found that the timing of applications governed the magnitude of the cytokinin response. For example, the six-leaf stage is the ideal time for the first kelp foliar in field crops. When the leaves are fully expanded, the response is minimal. In orchard crops, the magnification of growth during the vegetative phase is similarly related to the level of leaf expansion. If attempting to enhance cell division at the growing tips, then a foliar application of kelp before or during the early spring flush is the most appropriate timing. Similarly, the cell division stage during early fruit formation and the subsequent cell enlargement stage during fruit filling are both times when cytokinins will provide a desired boost.
During Dr Blunden’s research trials, it became apparent that the most dramatic cytokinin response was associated with plants that store carbohydrates. Sugar beet, sugar cane, potatoes and other root crops all fall within this category. The twin benefits of enhanced chlorophyll development and stability combined with delayed senescence increases sugar and carbohydrate levels in these crops. Improved chlorophyll management ensures increased photosynthesis and, when the flow of photosynthates (plant sugars) continues from the leaves to the roots for a prolonged period due to delayed senescence, then it is inevitable that more sugar and carbohydrate will be present in the end product.
Dr Blunden’s work with potatoes produced remarkable results. In trials, which were repeated eight times, he achieved consistent yield increases of 15% to 20% in potatoes foliar-sprayed with kelp. Subsequent research by major Canadian kelp producers has replicated these results. Most research has also found a uniformity of size, which has considerable marketing appeal. Blunden also found that sprouting could be manipulated with kelp. If potatoes are dipped in a weak kelp solution (1 gram of soluble kelp powder per litre), there is an increase in the number of sprouts and the rate of sprouting. Conversely, a high concentration of 25 grams of kelp powder per litre can bring sprouting to an absolute halt. This can be an effective technique to prolong shelf-life.
The production of more sugars is not just relevant to carbohydrate-storing plants, as all plants benefit from higher brix levels (dissolved solids including minerals and sugars). Brix levels are also a reflection of mineral levels, and high-brix plants will be more productive, and less attractive to disease and pest organisms, and they will tend to handle all forms of stress more effectively. In fact, many of the benefits attributed to kelp are directly or indirectly related to the brix-building capacity of this botanical marvel.


Comprehensive research supports a smorgasbord of stand-alone or synergistic benefits associated with seaweed application. There are numerous individual and interrelated benefits, including:

  1. Broad-spectrum Mineralisation: Some seventeen elements are currently considered in crop nutrition, but every few years science seems to ‘discover’ the potential of another previously ignored trace mineral. Silicon is the current flavour of the month. The fact is that there are no accidents in nature. If there were more than seventy minerals in that first cell, then it is a safe bet to assume that all of them have a role to play in plant nutrition and human nutrition, whether or not we understand their roles and interrelationships. Kelp contains the full mineral spectrum, because it grows in seawater. There are never droughts or crop failures in this aquatic environment and an abundance of food is always assured, because, as we impoverish the land through poor management, the eroded material simultaneously enriches the ocean (In some cases, the ocean is actually overloaded with nutrients due to run-off, but marine algae, like blue-green algae on land, are the least effected by these excesses. In fact, they sometimes thrive in these conditions).
  2. Natural Chelation: Chelation involves the neutralisation of positively charged elements (cations) to facilitate their easy entry into the negatively charged plant. Minerals can be seven to ten times more plant-available in chelated form. Kelp contains a powerful chelating agent called Mannitol, which naturally chelates the full suite of cations already present in seaweed. There is also sufficient Mannitol (10% of dry weight) to offer chelation capacity for any other cations that may be applied in conjunction with kelp. There is a reported synergy with iron (a cation) and kelp, for example, where a pronounced greening response is evident, due to improved iron uptake through chelation in conjunction with the chlorophyll-enhancing capacity of cytokinins.
  3. Increased Yield: Increased root growth is an important part of yield building. In turf trials at Virginia Polytechnic Institute, kelp-treated plots had 67% to 175% more roots than untreated plots, and plots treated during autumn showed a 38% increase in spring growth and 52% more roots than untreated crops. The Clemson research group demonstrated significant improvements in yield and quality of vegetable crops and soybeans. Foliar applications of seaweed consistently increased vegetable yield from 15.5% to 26.4% during a three-year trial period, and there were marked increases in nodulation and yield of soybeans (refer to the book ‘Seaweed and Plant Growth’ by T L Senn, Ph D, available from NTS).
  4. Improved Soil Structure and Water Holding Capacity: The vast majority of kelp research relates to foliar fertilising, but there are also considerable benefits associated with the application of kelp meal to the soil. Kelp meal contains very high levels of alginate. If you take a tablespoon of kelp meal and place it in a glass full of water, the solution will rapidly turn into a dense jelly. This is the swelling reaction of alginic acid, and it has profound implications for drought-stressed soils. In the soil, alginic acid combines with metallic elements to form cross-linked polymers of greatly increased molecular weight. These salts swell when wet and retain moisture tenaciously. In the process, they help the soil to form a crumb structure. Part of this crumb forming process is physical and part is biological.
  5. Pronounced Beneficial Fungal Promotion: The biological link to crumb formation is related to the promotion of fungi. Leading US microbiologist, Professor Elaine Ingham, has demonstrated that the majority of Australian soils are seriously deficient in beneficial fungi. Fungi are more susceptible to farm chemicals than other microbes. Kelp contains a rich lode of long-chain sugars, which are specific fungi foods. Fungi form the aggregates which are the essence of crumb structure. They are also intimately involved in nutrient availability, decomposition and optimal plant health.
  6. Rescue Remedy: Stress in plants, as in animals, is a reaction to some kind of threat or environmental change and it generates a plant response. The organic growth compounds found in seaweed can have a huge impact on controlling or reducing that stress. Stress can be linked to growth phases. Germination is the first stress period. A kelp-based starter solution will enhance germination rates and reduce germination time. Dr Senn’s team at Clemson worked with twelve different varieties of seeds and found an average 25% increase in germination when the seeds were soaked in a diluted kelp solution for a thirty-minute period prior to planting. Gibberellins appear to play a part here. Gibberellic acid is a proven germination promoter. Lettuce seeds, for example, will germinate in the dark with gibberellic acid. The switch from vegetative to the reproductive phase can also be stressful. A kelp spray prior to budburst has proven very productive. Gibberellins have been linked to the onset of flowering, while cytokinins have been linked to bud formation. Drought and waterlogging are other common sources of stress. During periods of drought, the naturally occurring cytokinins, which govern the closing of stomata to reduce transpiration from the roots, are seriously decreased. The cytokinins found in seaweed help compensate for this shortage. Waterlogging also disrupts cytokinin translocation and, once again, a kelp supplement will be beneficial.
  7. Frost Resistance: Kelp is a highly effective brix-builder. High-brix plants have a higher sugar content, which translates to a lower freezing point. A two to five degree frost protection has been recorded. Kelp also contains abscissic acid and polyamino compounds, which have also been shown to protect crops from frost damage. The Tasmanian Department of Agriculture found excellent frost damage reduction associated with Australian bull kelp (Durvillea potatorum) during research trials in that state.
  8. Enhanced Resilience: Anecdotal evidence, since the 1940s, has highlighted a link between organic growth compounds and plant resilience. Comprehensive experiments carried out in the 1960s, involving red spider mites in peaches and apples and aphids on strawberries, confirmed this link. The gibberellins in kelp seemed to be the key, as subsequent experimentation using gibberellic acid has produced a similar response to red spider mites.
  9. Increased Shelf-Life: Experiments with peaches at Clemson University produced a 300% decrease in susceptibility to post-harvest rot for crops that had been foliar-sprayed with kelp twice before harvest. There also appears to be considerable potential for post-harvest dipping. A significant increase in the shelf-life of capsicums has been demonstrated following immersion in seaweed extract.
  10. Improving Animal & Human Health: Kelp is a widely recognised stockfeed supplement. The broad-spectrum mineralisation is part of the appeal, particularly since the minerals are all delivered in chelated form. However, there are other factors influencing the success of the supplement. Kelp contains high levels of the trace element iodine. Iodine is extremely beneficial for cattle and most other animals, with the exception of horses, which are sensitive to excessive iodine. Kelp has a unique detoxifying capacity to help remove pollutants. There is no shortage of pollutants in our chemical-drenched society. In fact, Watanabe, a Japanese scientist, discovered in 1968 that a certain species of kelp can even help overcome the toxic effects of nicotine. The stress-relieving or rescue remedy capacity of kelp evident in plant life also appears to be relevant with animals and humans, and there is certainly no shortage of stress in the modern world.


For more information call the Kelp Help Line on +61 (0)7 5472 9900.

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