Managing plant nutrition - macro nutrients

Date posted: 19 December 2013

While plants can make their own food (sugar and starch for energy) via photosynthesis, they need a range of other nutrients for optimal growth and development.

There are 10 macro nutrients and seven micro nutrients essential for cereal crop growth... Of these, carbon and oxygen are absorbed from the air while the others are obtained from the soil and taken up by the plant roots.

There are two main groups of nutrients; macronutrients such as nitrogen, phosphorous, potassium, calcium, sulphur, chlorine and magnesium, which are required in large amounts, and micronutrients, such as boron, cobalt, copper, iron, Manganese, Molybdenum and zinc, which are required in small (micro) amounts.

Nutrients affect all aspects of plant growth – from height, to number of stems, grains and leaves size and even the ability to respond to environmental stress. A deficiency of any nutrient may limit growth, which means there will be less grains produced.

Farmers must become skilled at assessing the plants health. A plant lacking in nutrients might have yellowing of leaves, stunted growth or a change in colour of the leaves.

There are a few different ways that farmers cure nutrient deficiencies. A common option is application of fertiliser – just like for plants at home – but also sometimes a foliar (leaf) spray is used for some micronutrients.

A nifty way to prevent nutrient deficiencies is what’s called crop rotation. Crop rotation means rotating different cereals between paddocks – for instance in one paddock you plant barley, then the next year you plant lentils. This is because while barley consumes lots of nitrogen, lentils can fix nitrogen - which means the soil will have lots of nitrogen ready for the next year’s crop!

Whoever said plants aren’t clever!

Activity

This week’s activity is a bit of fun... Check out these farmers having fun growing our food.


Recent posts

Goodman Building restoration works wins industry award

18 July 2023

Have you ever driven past the beautiful heritage-listed Goodman Building when passing the Garden on Hackney Road? Did you know this building was formerly the base for the Municipal Tramways Trust but now serves as the Botanic Gardens and State Herbarium administration building.

Beneath the waves: Discovering nature's hidden ocean gems

07 June 2023

World Ocean Day is an annual celebration held on 8 June which unites and rallies the world to protect and restore our blue planet. In our latest blog, State Herbarium's Jem Barratt takes a deep dive into how its scientific work focusing on seagrasses and seaweed helps with the restoration and preservation of our ocean ecosystems.