In the world of agriculture, the concept of nitrogen fixation is critical. Nitrogen is a key nutrient required by plants to flourish. However, most plants cannot directly take nitrogen from the atmosphere, which comprises approximately 78% nitrogen. Instead, they require a process known as nitrogen fixation, which involves converting atmospheric nitrogen into a form that plants can use.
As you delve into the world of organic farming in the United Kingdom, certain plants should be on your radar. Specifically, these are plants known to enhance nitrogen fixation and promote soil fertility. This article will spotlight five specific plants that organic farmers in the UK commonly use to boost nitrogen levels in their soil.
Leguminous Plants and Nitrogen Fixation
If there’s one group of plants renowned for their nitrogen-fixation capabilities, it’s the legume family. They have a unique relationship with a bacteria group called Rhizobia, living in nodules in their roots. The Rhizobia bacteria convert atmospheric nitrogen into a usable form, providing nutrition for the plants.
Clover
Clover is a common sight in UK pastures and is extensively used in organic farming. This leguminous plant is renowned for its capacity to enrich soil with nitrogen. The most common types used in the UK include white clover (Trifolium repens) and red clover (Trifolium pratense).
Clover serves multiple purposes on an organic farm. Apart from its nitrogen-fixation capabilities, it also serves as a staple forage crop for livestock due to its high nutritional content. It’s durable and can withstand different climates, making it an excellent choice for UK organic farms.
Beans
Beans, specifically fava beans or broad beans (Vicia faba), are a popular choice among UK organic farmers. They are not just nutritious for humans but also for the soil. They have substantial Rhizobia colonies, which aids in nitrogen fixation.
Beans can be intercropped with other plants. They provide a symbiotic relationship where they enrich the soil with nitrogen, while other crops protect the beans from pests.
Non-leguminous Plants and Nitrogen Fixation
While legumes are famed for their nitrogen-fixation capabilities, a few non-leguminous plants also contribute to this process. Their role in organic farming is often undervalued but they can be an excellent addition to your organic farming practices.
Alder
Alder trees, specifically the common alder (Alnus glutinosa), are native to the UK and are a unique nitrogen-fixing tree. They do this through a symbiotic relationship with a bacteria called Frankia alni.
Alder trees can be used as windbreaks on a farm. Their leaves, when shed, enrich the soil and increase its fertility. They are also ideal for establishing along riverbanks or in other wet areas of a farm, where they can help prevent soil erosion.
Sea Buckthorn
Sea buckthorn (Hippophae rhamnoides) is a versatile plant native to the UK and is known for its nitrogen-fixing capabilities. It accomplishes this through a symbiotic relationship with Frankia bacteria, similar to alder.
In addition to its contribution to soil fertility, sea buckthorn is a hardy plant that provides excellent shelter to birds and insects. Its leaves, when shed, decompose into the soil and enhance its fertility.
The Role of Nitrogen Fixing Plants in Organic Farming
Nitrogen-fixing plants play a pivotal role in organic farming. They naturally enrich the soil with nitrogen, reducing the need for synthetic fertilisers. They also contribute to maintaining the overall ecosystems on the farm by improving soil structure, reducing erosion, and providing habitat to wildlife.
The key in organic farming is to understand the symbiotic relationship that these plants can have with each other and the soil. A balance of these nitrogen-fixing plants along with other crops can create a sustainable, productive, and ecologically beneficial farming system.
The Impact of Crop Rotation on Nitrogen Fixation
In the quest for sustainable organic farming, crop rotation plays a crucial role. This farming practice involves growing different types of crops in the same area, in sequenced seasons. It not only manages soil fertility, but also helps manage pests and diseases. Nitrogen-fixing plants, when included in the crop rotation cycle, can help replenish nitrogen levels in the soil.
The benefits of crop rotation are manifold. Firstly, it disrupts the lifecycle of pests and diseases, reducing their impact and the need for synthetic pesticides. Secondly, it helps to balance out the nutrient requirements of different crops. For instance, legumes, which are nitrogen-fixing plants, can be followed by a crop that is a heavy nitrogen feeder, such as corn. The corn can then be succeeded by a light feeder that does not require much nitrogen. This approach ensures that the soil’s nutrient levels are maintained sustainably.
Within the UK, the crop rotation system often includes clover and beans. After a heavy nitrogen-feeding crop, a legume is planted to restore the nitrogen balance. These legumes not only add nitrogen to the soil, but their deep roots also help improve soil structure and aeration, creating a better environment for the succeeding crop. Additionally, legume crops can be used as green manure, wherein they are plowed back into the soil to further enhance its fertility.
Crop rotation, when executed properly, can significantly enhance the productivity and sustainability of organic farming in the UK. It leverages the natural capabilities of nitrogen-fixing plants to improve soil fertility, while maintaining a balanced ecosystem.
Conclusion: The Power of Plants in Enhancing Nitrogen Fixation
The importance of nitrogen to plant growth cannot be overstated. Yet, the challenge lies in harnessing this vital nutrient in a sustainable and organic way. Nitrogen-fixing plants, such as legumes and certain non-leguminous varieties, offer an effective solution to this challenge.
In the UK, organic farming has embraced the power of these plants, incorporating them into farming practices and crop rotation cycles. Clover, beans, alder, and sea buckthorn are among the plants commonly used for their nitrogen-fixing capabilities. Their ability to form symbiotic relationships with nitrogen-fixing bacteria like Rhizobia and Frankia makes them invaluable assets to organic farming systems.
In addition to enhancing soil fertility, these plants provide numerous other benefits, such as preventing soil erosion, improving soil structure, and providing habitat to wildlife. They also contribute to a balanced ecosystem, where each plant, insect, and animal has a role to play.
In conclusion, the journey towards sustainable and organic farming is complex and challenging. It involves understanding the intricate relationships between different elements of the ecosystem and leveraging them to our advantage. Nitrogen-fixing plants, with their unique capabilities, provide an effective means of enhancing soil fertility organically, making them an integral part of organic farming practices in the UK.
