Magnesium Deficiency

Pasture soils in many parts of Victoria and NSW suffer from magnesium deficiency, raising risk of incidence of grass tetany in beef and dairy herds.

Grass tetany can result from a number of causes, but a common reason is a lack of magnesium.

After just 12 months, many MagPhos users have reported large reductions in incidences of grass tetany, and in some cases, none at all.

Rainfall, pasture species, grazing management and nutritional fertility all influence the ability of a pasture-based enterprise to reach its full potential.

The nutrients calcium, potassium, nitrogen and phosphorus each have an impact on the potential pasture yield; however, in some cases where adequate levels of these elements are present, a magnesium deficiency can prevent a pasture from achieving its maximum yield.

MagPhos™ has been developed by BioAg to supply a well balanced, quick acting, form of magnesium and phosphorus for Australian pastures, particularly in those areas of Victoria and NSW which suffer from magnesium deficiency.

Magnesium deficiency raises the risk of the incidence of grass tetany in beef and dairy enterprises.

Because of the requirement for a quick acting form of magnesium, coupled with phosphorus, dolomitic magnesite is used in the manufacture of MagPhos, rather than conventional dolomite, because of its rapid breakdown and greater plant availability.

MagPhos™ – Guarding against magnesium deficiency in pasture and the risk of grass tetany.

Together with phosphorus, magnesium is a very important element for plant growth and resultant animal health.

The industry is familiar with the use of magnesium in dairy feed rations, and caustic magnesium oxide lick blocks, or dry licks containing magnesium in grazing enterprises.

The requirement for supplementation is a good indicator that the pasture lacks an adequate level of magnesium.

A good way to indentify the deficiency is to conduct a number of tissue tests throughout the season to measure the magnesium level in the pasture.

Magnesium is critical for photosynthesis – a process in which sunlight is converted into energy for plant growth.

A key component of the process is chlorophyll, which is the light absorbing element in plants – essentially the pigment that provides plants with their green colour.

Lack of colour in pasture is often associated with nitrogen deficiency, but because of the presence of magnesium in chlorophyll, plants can also display the same symptoms as those of nitrogen deficiency when an insufficiency of magnesium is the cause.

Just as humans fail to operate adequately without energy, a deficiency in magnesium will inhibit a plant’s ability to convert light to energy, affecting its ability to reach its full potential.

Five things to consider in identifying magnesium deficiency in pastures:

  1. Are there occurrences of grass tetany in my stock?
  2. Is it necessary to supplement feed magnesium regularly?
  3. Do soil or tissue tests indicate a magnesium deficiency?
  4. Do the pastures display nitrogen deficiency symptoms (once nitrogen is applied is a short lived response evident)?
  5. Is dolomite currently applied and does it appear to be too slow acting?

If any of these problems occur within your enterprise, it is probable the there is a magnesium deficiency in your soil, and that an application of MagPhos will improve your pastures.