Function of Nutrients in Plants

Notes for RHS Level 2: Unit 1: Element 2 Role of Nutrients: AO1: Function of Nutrients in Plants

The essential nutrients required for plant growth and development are divided into two categories: macronutrients and micronutrients.

Macronutrients are elements that plants require in larger amounts, with the elements used in the highest quantities gained from the air, being carbon, hydrogen, and oxygen. Erosion slowly releases all the other minerals from the Earth’s rocks.

Whether minerals are obtained from organic sources, such as composted vegetable matter, or inorganic sources, such as liquid blends of chemicals, does not matter to the plant as the mineral elements are the same.

However, the main difference is that organic sources slowly release small quantities of minerals into the soil, whereas inorganic fertilisers use concentrations of specific elements prepared for defined and immediate usage.

N-P-K ratios on fertiliser display the ratios between nitrogen, phosphorus, and potassium (K refers to the now obsolete neo-latin kalium). For example a formulation using a ratio of 0-10-10 would promote flower and fruit set.

The following table lists the macronutrients and their functions in plants:

 

Nutrient               Function

Nitrogen             Essential for the production of chlorophyll, amino acids, and nucleic acids.

Phosphorus        Involved in the production of ATP, DNA, and cell membranes.

Potassium           Regulates water balance, activates enzymes, and helps in the production of ATP.

Calcium              Essential for cell wall formation, cell division, and cell elongation.

Magnesium         A component of chlorophyll, and is involved in photosynthesis and enzyme activation.

Sulfur                  Required for the production of amino acids, proteins, and enzymes.

Carbon                Required for photosynthesis, the process by which plants produce their own food.

Oxygen               Required for respiration, the process by which plants convert food into energy.

Hydrogen            Required for the formation of organic compounds, such as carbohydrates and proteins.

 

In addition to macronutrients, plants also require micronutrients in smaller amounts for their growth and development. The following table lists some of the essential micronutrients and their functions in plants:

 

Nutrient               Function

Iron                    Essential for the production of chlorophyll and involved in photosynthesis.

Boron                 Required for cell wall formation, pollen tube growth, and seed production.

Manganese         Involved in photosynthesis, respiration, and enzyme activation.

Molybdenum      Required for nitrogen fixation and the production of enzymes.

 

Plants lacking macronutrients and micronutrients will find their growth and development adversely affected, leading to mineral nutrient deficiencies and disorders. The symptoms of nutrient deficiency can vary depending on the nutrient that is lacking. For example:

Nitrogen deficiency:        Plants may exhibit stunted growth, yellowing of leaves, and reduced leaf size.

Phosphorus deficiency:   Plants may exhibit stunted growth, dark green leaves, and reduced root growth.

Potassium deficiency:     Plants may exhibit yellowing of leaf margins, wilting, and reduced growth.

 

Deficiencies will be explored further in a future post.

Impact on plant specification on biosecurity (UK)

 Notes for Unit 1: Plant Specification: Integration: AO3 Impact on specification on biosecurity

 

Plant specification has a significant impact on biosecurity. When ordering plant material, it is important to consider the biosecurity of the plants you order. You should only order plant material from reputable suppliers who follow strict biosecurity protocols.

There are also strict rules for the importation of plants into the UK from the EU, including the necessity for a phytosanitary certificate. This certificate is issued from the plant health authority of the country where the plant material originates to guarantee that the material has been officially inspected, is free from pests and diseases and meets the legal requirements for the material to enter GB. There are costs associated with the importation process related to applying for phytosanitary certificates, checks and inspections that an individual importer is expected to meet. This does not apply to all plants, as there is a short list of low-risk plants that can be imported from the EU and third countries without the phytosanitary certificate. At the time of writing, this includes, but is not limited to, pineapple, persimmon, and banana. See the links below for further information.

 

UK Plant Passport

In addition, the UK has introduced a plant passport scheme and plants cannot use an EU plant passport for movement in the UK. While garden centres do not need to pass on a UK plant passport to customers, online retailers must supply the passport for traceability purposes.

 

The plant types you choose can also have an impact on biosecurity. Different plant types have different susceptibility to pests and diseases. For example, some plant types such as annuals and biennials are more susceptible to pests and diseases than others such as perennials. Schemes such as the RHS Award of Garden Merit have a series of requirements that ensure plants awarded are reasonably resistant to pests and diseases.

 

Material type is another important factor to consider when ordering plant material. The three main types of plant material are pot-grown, bare root, and rootballed / burlap. Each material type has its own advantages and disadvantages in terms of biosecurity. For example, bare root and pot grown plants are financially cheaper, but are more susceptible to damage during transportation, which can increase the risk of pest and disease transmission. While, the well developed root systems of rootballed/burlap plants, which are available during the dormant season for the species, are less susceptible to damage and therefore less likely to be infected with disease.

Bare root, rootballed, and potted plants.

 

Production method is also an important consideration. Plants can be grown using different methods such as conventional, organic, or biodynamic. It is important to choose a production method that aligns with your values and requirements.

Conventional production methods use synthetic fertilizers and pesticides to promote plant growth and control pests and diseases. While these methods are effective, they can have negative impacts on the environment and human health.

 

Organic production methods use natural fertilizers and pest control methods to promote plant growth and control pests and diseases. Organic methods are more sustainable and environmentally friendly than conventional methods, but they can be more expensive and less effective. For instance, the reliance on natural predators to remove pests can be less effective, while using natural compost and manure can introduce soil-borne diseases.

 

Biodynamic production methods are similar to organic methods, but they also incorporate spiritual and mystical practices. Biodynamic methods are less common than conventional and organic methods, but they are gaining popularity due to their focus on sustainability and holistic plant health. However, as with organic production, the reliance on natural predators to remove pests can be less effective, while using natural compost and manure can introduce soil-borne diseases.

 

Finally, environmental considerations are also important when ordering plant material. You should choose plants that are well-suited to your local climate and soil conditions. You should also consider the environmental impact of the production and transportation of the plant material.

 

By considering these factors, you can ensure that you order plant material that is healthy, sustainable, and well-suited to your needs.

 

Links for further information:
https://www.rhs.org.uk/prevention-protection/importing-and-exporting-plants

https://www.gov.uk/guidance/apply-for-plant-export-certificates-and-inspections

https://aphascience.blog.gov.uk/2023/03/01/plant-passports/

New Plant Biosecurity Strategy - UK Plant Health Information Portal (defra.gov.uk)

 

Plant Profile: 𝐒𝐧𝐨𝐰𝐝𝐫𝐨𝐩𝐬

Galanthus nivalis, commonly known as the snowdrop (or ‘Shame-faced maiden; in Wiltshire), is a perennial bulbous plant that belongs to the Amaryllidaceae family. It is native to Europe and the Middle East, and is widely cultivated in gardens and parks across the world. The first records of the snowdrop growing wild in Britain hark back to the 1770s.

The plant has narrow linear leaves and produces a single white flower that hangs from a slender stem. The flower has six petals, three inner and three outer, and is surrounded by a green ovary.

The snowdrop has a rich social history and is associated with hope and purity. It is one of the first plants to emerge from the cold winter soil, and has been used as a symbol of the coming of spring and the end of winter. The plant has also been used in traditional medicine to treat a variety of ailments, including headaches, fever, and joint pain.

There are several varieties of Galanthus nivalis, including the ‘Flore Pleno’, which has double flowers, and the ‘Viridapice’, which has green-tipped petals. The snowdrop has also been the subject of mythology and folklore and is said to have been created by the Greek god of the north wind, Boreas.

Said to be best planted ‘in the green’, rather than dormant bulbs, the snowdrop is known to attract bees and other insects, and is an important source of early-season nectar and pollen. It is also a valuable food source for small mammals such as voles and mice.

Galanthophiles, those that collect snowdrops, have been known to bid into the hundreds for just a single bulb, with the world’s most expensive snowdrop bulb being sold for £1,850 in 2012. The Golden Fleece snowdrop took 18 years to develop and holds the record for a single bulb, which was sold for £1,390.

In conclusion, Galanthus nivalis is a beautiful and fascinating plant with a rich history and mythology. Its delicate white flowers and slender stems make it a popular choice for gardens and parks, and its association with hope and purity has made it an enduring symbol of spring and new beginnings.

Here are some tips for growing snowdrops

Planting: Snowdrops should be planted in well-drained, nutrient-rich soil in a sunny or partly shaded location. They should be planted in the autumn before the ground freezes. Plant the bulbs two to three inches deep and two to four inches apart.

Watering: Water the bulbs regularly and keep the soil moist but not soggy.

Light: Grow snowdrops in moist but well-drained, hummus-rich soil in dappled shade.
Try growing snowdrops beneath deciduous shrubs, such as Cornus alba ‘Sibirica’, or along the front of borders where herbaceous plants can provide ground cover when the snowdrops are dormant.

Propagation: Snowdrops can be propagated by division in the spring or summer, or by seed in the autumn

Photographs: Galanthus nivalis, snowdrop cultivated variety, snowdrop seedheads.