Seaweed vs. Other Organic Fertilizers: 5 Reasons Seaweed Wins
This week we have been out and about meeting and talking with many people about our favourite topic – seaweed! It’s always a great feeling when you meet someone who is already invested in seaweed and you embark on a seaweed exchange of the huge variety benefits and uses that we are finding to use seaweed for. In this week’s blog, I am going to talk through a few of the benefits from using a biological fertiliser such as seaweed, compared to the chemical fertilisers that we often see when we visit our local garden centres and stores. We have included below our top five reasons why putting down your chemical fertilisers and trying organic liquid seaweed, a biological, natural alternative will leave you wondering why you hadn’t done it sooner…
1. Soil acidification upsets micro-organisms that are vital for optimum soil cycling.
Soil acidification reducing microbes are essential for the soil as they fundamentally reduce the amount of organic matter in found in the soil. Having more biodiversity of invertebrates and microbes in the soil is great news. They have an incredibly important role of taking various inorganic materials and make them accessible for plants to use. They can do this by feeding on the inorganic matter and processing the molecules into organic matter. When the molecules become organic, plants are then able to absorb the nutrients through the root systems and use them for their multitude of chemical processes needed for growth. Soil acidification occurs when a build-up of hydrogen ions takes place within the soil. The amount of hydrogen ions found in the soil will determine how acidic the soil is. Soil microbes do not like an acidic environment and become impaired in acidic conditions, slowing down their biological processing. Nutrient cycling will also be slowed down in acidic soils, limiting root growth and rhizobia survival and their ability to form nodules. The ammonia used in chemical fertilisers also contains hydrogen molecules that are broken down into acidic hydrogen ions when they enter the soil. Eventually, the soil’s pH will decrease and become more acidic overtime. Depending on the time of year and availability of water, it can take a year or even longer to neutralise the effects of soil acidification. In particular, water uptake is generally slower over the winter months and changes to the soil will take longer over this season. Adding neutralising alternatives to the soil can aid and help increase the return of regenerated soil. Seaweed is a great option for the soil and can be applied as a mulch to help prepare the soil for the following season. A mulch is a layer of biological material that is applied to the soil surface (or just under) and it provides the right conditions (moisture, nutrients and heat) for microbes to munch into and improve the health of the soil and the fertility of the soil. Macrobacteria and mycelium will give you an indication of the different stages of your soil health. The mycelium provides an underground network connecting individual flora within a population to one another. This gives them the ability to send chemical signals when they are low in nutrients, if they are diseased or infected with pathogens and the mycelium network will respond by sharing nutrients from a healthy plant to an unhealthy plant.
2. Seaweed fertilisers naturally increase in soil fertility.
The use of salt in the chemical fertilisers reduces soil fertility, meaning less flora can inhabit the soil and grow within that space. An increase in salts within the soil and round the roots will cause water to be drawn away, consequently the plant will not be able to find water to uptake through the roots and can lead to plant dehydration. Soil salinity can occur naturally between irrigation periods. At the start where the soil has been irrigated, there is high water availability. Over time, naturally the plants will uptake this water, eventually leaving the water in the soil remaining more tightly locked and harder to access. Evapotranspiration takes place leaving soils heavier in salinity, due to water being lost from the soil through air evaporation and the plants through transpiration. Add in the addition of chemical fertilisers, which contain high concentrations of salts, this will increase the process making it increasingly difficult to receive the nutrients and water needed. The presence of the salts makes for unfavourable and undesirable conditions. Soil microbes including bacteria and fungi find salty, saline conditions tricky to navigate. The increase of salts slows down microbe respiration and their ability to mineralise nitrogen so that is accessible to plants. The salts will also inhibit the activity of soil enzymes, responsible for catalysing biological chemical reactions. We are aware that seaweed comes from the ocean and the oceans are a salty environment. Seaweed can be applied directly to the soil, when it is usually washed in fresh rainwater or dechlorinated water at the processing stage to remove excess salts and reduce the overall salinity. The seaweed can be applied in ‘wet’ ‘dried’ or liquid form, as it is also considered a natural stimulant, meaning it will trigger microbes to carry out their biological processes, including enzyme activity too.
3. Chemical fertilisers increase the rate of soil leaching
Soil leaching occurs when chemical fertilisers are applied directly to the soil increasing the volume of nitrates (form of nitrogen) and phosphates found in the soil. When water is added to the soil, through natural and human intervention the nitrates and phosphates are dissolved and can move more freely through the soil found below the root area, creating run-off to our waterways. This run-off or drainage is moving the dissolved molecules from the chemical fertilisers into our aquatic environment, causing pollution and changes to the ecosystems.
4. Chemical fertilisers can lead to eutrophication a process affecting diversity in the marine and freshwater ecosystems.
Eutrophication is a concern for many ecologists and environmentalists. As stories of water pollution levels in lakes and rivers are rising nationally, more communities are taking a personal interest in the remediation process and returning their waters to their nutrient rich and biodiverse state. What is eutrophication? It is where the balance of minerals and nutrients becomes unstable due to an excess entering the waterway causing overwhelming growth of algae, leading to oxygen depletion. Species living in the ecosystem where eutrophication takes place, will initially thrive on the availability of nutrients, but over time due to the overpopulation of algae at the water’s surface they will be deprived of oxygen and sunlight, consequently dying through starvation of O2. The build up of excess nutrients As mentioned above any chemicals that are applied to the soil and the land, due to rainfall, will pass inorganic and organic nutrients along our waterways into our streams, rivers and lakes. Toxins enter the water in an inorganic state where flora and fauna are unable to absorb and use them, creating a build up. Build of ammonia, ammonium, nitrate and phosphates all contribute to the eutrophication process with ammonia being toxic to fish species, nitrates causing health implications to humans and phosphates attaching to soil particles. Cyanobacteria will create the severe blooms that will lead to ill health concerns for humans and also effect the aquatic ecosystem health too.
5. Chemical fertilisers may offer a short term gain but inevitably create long term deficit.
There is no denying that chemical fertilisers have been created and produced, to provide fast results giving the impression that your flora or produce are benefitting from them. Another reassurance is that you can see fairly quickly that chemical fertilisers do what they say they will do. However, this occurs for a short period of time and creates a drought environment with dehydrated soil. A healthy soil system will have a cycle that is self-maintaining and can cycle through nutrients regularly. Sometimes, it may need a little support and organic fertilisers, such as liquid seaweed concentrate provides the nutrients supporting the invertebrates playing the vital roles of the soil cycle processing and overall health. Healthy, enriched soil cycling will help you to create a nutrient rich environment for the following seasons, compared to chemical fertilisers requiring soils to be cleared and prepared again ready for the next growing season.
The use of biological fertilisers bring many advantages and we have not outlined them all here, just a few of our top reasons for switching to an organic, natural and biological alternative. Liquid seaweed provides so many benefits to the soil and flora. If you would like to find out more about these benefits read our next blog post here. If you would like to learn more about the history of seaweed harvesting in Cornwall, read our blog here.