Enhancing the Performance of Dolomite.

Enhancing the Performance of Dolomite.

Peter Burton
19th April 2010

Dolomite mined at Mt Burnett near Collingwood comes to the North Island via a number of routes.  In the 1950’s dolomite was transported from Tarakohe to Wanganui using a scow.  Scows are relatively small flat-bottomed vessels capable of being grounded on the beach, loaded, and floated off at the next high tide.

More recently most of the dolomite has been trucked the 40km from the mine near Collingwood to Tarakohe where it was loaded into barges and towed to the Port of Wanganui.

Two years ago in order to increase efficiency and ensure dolomite is available to all farmers at the lowest possible price a ship capable of carrying 500 tonne has been used, and dolomite has recently been shipped direct to Wanganui, Whangarei, and Mt Maunganui.

Farmers using dolomite regularly talk of improvements in animal health, which over time result in few health issues of any type, excellent persistence of pasture, and the ability of their properties to withstand long dry periods and recover comparatively quickly once warm rain arrives.

One of the reasons for this improvement in overall farm health is the soil conditioning effect of dolomite.  Applied at between 215 – 220kg/ha annually dolomite applies 25kg/ha of magnesium and 52kg/ha of calcium, with rates above this seldom providing better performance.

The development of DoloZest was as a result of observing over a number of years further increases in total farm performance on properties where soil life was regularly fed with small quantities of fowl manure or cowshed effluent.

DoloZest is the result of inoculating a small quantity of soft carbon with a wide range of soil friendly fungi and bacteria and mixing with dolomite.  Initial observations were encouraging with a rapid greening of pasture soon after application, a denser sward with outstanding clover growth.

Further monitoring followed using cages and monthly cuts recording dry matter production and pasture composition.  Over the last seven years much data from a number of properties has been obtained and a range of trends have become increasingly apparent.

Higher levels of dry matter are grown with indications that the quantity of major nutrient required to maintain soil test levels may be reduced.  Clover growth is more vigorous and less affected by flea and weevil.  Beetle damage also appears markedly less.

One of our monitored dairy farms is now into the fourth season without the use of worm drenches, however should need arise they will be used.

These observations fit with the philosophy that strong healthy organisms are more able to withstand damage by pest and disease. 

Healthy plants containing higher levels of soluble sugars ensure healthier animals.  Lambs are generally cleaner due to lower nitrate levels allowing more energy for growth.  Feed is better digested and dung more readily reabsorbed into the soil.

With increased clover growth the reliance on fertiliser nitrogen is also reduced.  Testing soon to take place will provide information on nitrate and phosphorus leaching.  Work with Graham Shepherds Visual Soil Assessment is presently providing high soil scores however due to prolonged dryness the pasture scores are lower than could normally be expected at this time of the year.

Healthy well-structured soils are able to recover more rapidly after a dry spell and in all but extreme situations the loss of pasture is minimal.  DoloZest may be applied at any time, an application between now and calving will speed soil and pasture recovery as well as ensuring minimal calcium/magnesium related problems in spring.