A sustainable alternative for agriculture

Fertilisers are chemical substances or compounds that are used to enrich the soil and provide plants with essential nutrients to promote their growth and development. These nutrients typically include macronutrients such as nitrogen, phosphorus and potassium, and micronutrients such as iron, manganese and zinc.

Although fertilisers are used to correct nutrient deficiencies, improve soil quality and increase crop productivity, they have caused soil and water pollution, acidification, loss of biodiversity and have made us dependent on them.

According to EEA data, EU countries used a total of 16.9 million tonnes of fertilisers in 2021. Of this amount, 65% will be mineral fertilisers and 35% organic fertilisers.

EEA

Why not organic compounds for use?

There is, however, an alternative: the use of organic fertiliser. This is a natural compound derived from organic materials (manure, compost, plant residues and other biodegradable waste) and, unlike synthetic chemical fertilisers, organic fertilisers do not contain artificial ingredients or manufactured chemical compounds.

Therefore, the use of organic fertilisers is considered a sustainable practice in agriculture and horticulture because it reduces reliance on synthetic chemicals and promotes a more natural nutrient cycle. It also helps maintain soil biodiversity and reduces the risk of water and environmental pollution.

Organic fertiliser types

According to Naeem et al (2020)¹ , maintaining soil fertility consists of retaining, cycling and supplying the nutrients necessary for plant growth over several years. This can be achieved through organic soil amendments, which are broken down by the action of soil fauna (e.g. microbial action) into simple elements that can be assimilated by roots (nitrogen, potassium, phosphorus, sulphur, etc.).

t would be fair to refer back to the publication by Naeem et al (2020) to identify those organic fertilisers that can be used to improve soil health:

Compost

Compost is an organic product obtained through the process of controlled decomposition of organic materials, such as food waste, garden waste, leaves, branches and other biodegradable materials. The main decomposers are bacteria, fungi and protozoa. 

Manure

Farmyard manure, made up of animal excrement together with straw and hay), has been the traditional fertiliser par excellence. Although it is readily available and contains all the nutrients required by plants, care must be taken because it may contain pathogens.

Green manure

This is non-decomposed plant matter, which can be obtained by collecting plant debris (leaves and branches) or by turning over some crops such as leguminous plants. 

Algae biofertilisers

These are organic products derived from seaweed (e.g. Azolla pinnata) and are used as a source of nutrients and soil amendments in agriculture and gardening. These biofertilisers are obtained through the processing of seaweed, which is rich in nutrients and minerals essential for plant growth.

fungal biofertilisers

Often called “beneficial fungi” or “mycorrhizal fungal inoculants,” these are products used in agriculture and gardening to promote plant growth and health by establishing a symbiotic relationship between plant roots and mycorrhizal fungi. These fungi form a mutualistic partnership with plant roots, in which the fungi provide additional nutrients and water to the plants, while the plants provide them with carbohydrates and other organic compounds.

It would be fair to refer back to the publication by Naeem et al (2020) to identify those organic fertilisers that can be used to improve soil health:

Compost

Compost is an organic product derived from the controlled decomposition of organic materials such as food waste, garden waste, leaves, twigs and other biodegradable materials. The main decomposers are bacteria, fungi and protozoa.

Manure

Farmyard manure (animal excrement mixed with straw and hay) is the traditional fertiliser par excellence. Although it is readily available and contains all the nutrients that plants need, care must be taken as it may contain pathogens.

Green manure

This is undecomposed plant matter that can be obtained by collecting plant debris (leaves and branches) or by turning over some crops such as legumes.

Algae biofertilisers

These are organic products derived from seaweed (e.g. Azolla pinnata) and used as a source of nutrients and soil conditioners in agriculture and horticulture. These biofertilisers are obtained by processing seaweed, which is rich in nutrients and minerals essential for plant growth.

Fungal biofertilisers

Often referred to as “beneficial fungi” or “mycorrhizal fungal inoculants”, these are products used in agriculture and horticulture to promote plant growth and health by establishing a symbiotic relationship between plant roots and mycorrhizal fungi. These fungi form a mutualistic partnership with plant roots in which the fungi provide the plants with additional nutrients and water, while the plants provide the fungi with carbohydrates and other organic compounds.

Conclusion

In a world where agriculture and horticulture are essential to our survival and well-being, it is vital to address the use of fertilisers, which have increased crop productivity but have also had a negative impact on soil and the environment. Synthetic chemical fertilisers have contributed to soil and water pollution, soil acidification and loss of biodiversity. They have also created an unsustainable dependency on these products.

But there is a more sustainable alternative: organic fertilisers. These natural compounds, derived from organic materials such as manure, compost, plant residues and other biodegradable waste, are environmentally friendly and promote a more natural nutrient cycle. Organic fertilisers enrich the soil, improve soil structure, promote soil biodiversity and reduce the risk of water and environmental pollution.

There are several types of organic fertiliser, including compost, manure, green manure, algal biofertilisers and fungal biofertilisers. Each offers specific benefits, from improving soil structure to stimulating plant growth and reducing dependence on chemical fertilisers.