‘Major’ and ‘Minor’ elements

Pasture health is the foundation of a productive farm. Understanding the role of major and minor elements in your soil can significantly improve pasture growth and quality. These essential nutrients support plant health, enhance livestock nutrition, and ultimately contribute to a more sustainable farming system. In this article, we explore the various elements that influence pasture productivity and provide practical tips for managing them effectively.

Chemical elements are divided up into two groups – major and minor

Major elements

• Nitrogen (N)

• Phosphorus (P)

• Potassium (K)

• Sulphur (S)

• Calcium (Ca)

• Magnesium (Mg)

• Sodium (Na)

• The tissues of plants and animals are made up of Carbon (C), Hydrogen (H), Oxygen (O), and about 15 mineral elements.

• The elements C, H, and O along with Nitrogen (N), Phosphorus (P), and Sulphur (S) make up the living matter in plants and animals, with Calcium and Phosphorus forming animal skeletal bones.

• The other elements are used in various body systems of plants and animals driven by enzymes and for nervous functions.

• An enzyme is a chemical used in a biological process but remains chemically unchanged.

Minor elements

• Boron (B)

• Iron (Fe)

• Manganese (Mg)

• Copper (Cu)

• Zinc (Zn)

• Molybdenum (Mo)

• Chlorine (Cl)

• Cobalt (Co)

• Selenium (Se)

• Iodine (I)

MAJOR elements for plants & animals

• There are at least 19 chemical elements required for plant growth.

• Each chemical element has one or more specific functions within the plant, which cannot be taken over by another.

• As the plant grows, the daily demand for nutrients increases.

• Of the major nutrients, Mg is essential for both plant and animal growth and health, and K and Na are often involved in animal health issues.

• The concentration of these elements in the soil can be increased by adding fertilisers, which then get into the plant and then the animal if the animal eats sufficient of the pasture.

MINOR elements for plants & animals

The essential minor or trace elements are:

All the trace elements are present in the soil, but how much and which ones get into plants depends on the soil parent material (where the soil came from), the soil pH, moisture, texture, and organic matter content.

• Old soils, which have been weathered and leached under high rainfall, have lower trace elements than young soils in drier areas.

• As soil pH goes up, the availability of trace elements (except Molybdenum) falls. Molybdenum is more available in acid soils.

• Soil organic matter is important in helping to bind and retain Cu, Zn, Fe, and Mn in the soil.

• Low moisture soils reduce the availability of Cobalt and Boron.

• Over time, trace element levels are lost from a grazing system, unless replaced in fertilisers.

• Copper is important in many aspects of animal health, and also for the nitrogen-fixing bacteria on clover roots.

• Cobalt is important as the bacteria in the rumen use it.

• Selenium deficiency is seen as the classical white muscle disease in lambs and calves.

• Iodine is associated with thyroid function in animals.

Testing for trace element deficiencies

• Laboratories can test the soil, pasture plants, and both blood and liver samples.

• There are some very clear rules on how this should be done, so check with a testing laboratory.

• The main concern is to prevent contamination of the pasture sample with soil, and sweat from your hands.

• Taking blood samples and liver biopsies on a live animal has to be done by a veterinarian.

• Liver samples can be taken at the time of slaughter, but this has to be arranged between your vet and the meat works.

• The testing organisations will provide a reference range for each element, so you can see if they are normal or not.

Other points

• You’ll see the terms ‘minerals’ and ‘trace elements’ used in relation to minor elements. Trace elements are as their name suggests – only needed in very small amounts.

• So it’s obvious that with all these different elements involved in plant and animal nutrition, any one of them or a combination of only a few can put things out of balance and affect performance.

• There’s always a great opportunity to cause panic among farmers when specialists and researchers in particular elements report their work – giving the impression that you need to start supplementing your soil or stock with extra elements, without proper testing of soil, herbage or blood having been done.

Times to monitor trace elements

How much is needed to correct deficiencies?

Seek advice from a consultant.

Summary

Pasture productivity hinges on the right balance of nutrients in the soil. Major elements, such as nitrogen, phosphorus, and potassium, are required in large amounts and play a critical role in plant growth. Minor elements, though needed in smaller quantities, are equally important for the overall health of your pasture. These include sulphur, calcium, magnesium, and trace elements like copper, zinc, and boron. Properly managing these elements can prevent nutrient deficiencies, optimise growth, and enhance forage quality.

Regular soil testing, along with targeted fertilisation, is essential to ensure that your pasture receives the nutrients it needs for maximum productivity and sustainability. By understanding the roles of these essential elements, farmers can make informed decisions that lead to healthier pastures and, ultimately, more productive livestock.

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