One of the many pleasing aspects to selling Golden Bay Dolomite is the development of long term relationships with all those involved, from the mine owners through to the end users.  It is particularly satisfying working with farmers and growers who experience and appreciate the unique benefits provided by dolomite.

Some years ago when suggesting to a retired boat builder that boats of modern design and construction were superior to hand built launches of 40 years ago he tersely replied that waves had not changed shape in that time and would not do so in the future.

Plant requirements for maximum production are no different now than they were 50 years ago.  One thing that has changed in that time is the use of fertiliser nitrogen.  In the late 1970’s and early 80’s pasture growth from permanent pastures without the use of fertiliser nitrogen could and often did exceed 18 tonne of dry matter per hectare annually.

Today total annual growth for permanent pastures seldom exceeds 15.5 tonne, a fact that is becoming increasingly recognised.   Given the loss of pasture plants under fertiliser nitrogen driven fertiliser programmes, do permanent pastures now actually exist?  There are an increasing number of properties where 15 – 20% of pasture is renewed or renovated every year.

Properties where dolomite is applied each year, the rate of application dependant on the need for magnesium, and little if any fertiliser nitrogen applied have a much reduced requirement for pasture renewal.

Pasture pulling in autumn occurs only where soils are too hard for pasture roots to penetrate easily. An obvious visual sign is grass plants perched with their crowns well above the soil surface.  The areas most affected are the high traffic areas around gate ways, water troughs, and sites where stock concentrate to feed.

The loss of pasture plants due to pulling is almost entirely preventable without the long term use of mechanical soil aerators

Earthworms and other beneficial soil dwellers are able to do this work on all soils, provided the conditions conducive to their activities are created.  Soils where test results indicate MAF QT levels of calcium exceeding 7, Base Saturation calcium in the 60 – 70% range, and soil pH between 6.2 and 6.5, nearly always contain sufficient calcium for strong earthworm and other beneficial soil dweller activity.

Golden Bay Dolomite, a proven soil conditioner in its own right, contains 11.5% magnesium, and 24% calcium.  Where magnesium is a requirement, as it is on most intensive dairy properties, an autumn application of 200 – 250kg/ha will kick start the process of improving soil health and providing conditions conducive to excellent plant persistence.

In an ideally structured soil, by volume 25% is air and 25% moisture.  Air and moisture are inversely related meaning that after rain moisture levels will increase as firstly large pore spaces are filled displacing air.

As soils dry out in summer the amount of moisture in the soil will decrease relative to air.  Where soils are dominated by very small pore spaces they tend to be poorly aerated, with moisture tightly held and slow to move. These soils after rain are also slow to become sufficiently moist for strong pasture growth.

Maybe a useful analogy is a vehicle fuel tank.  When designed with a very small breather they are frustrating slow to fill, however this is not necessarily related to the rate at which fuel is consumed.

Likewise soils with a higher proportion of space as macro pore space are not necessarily the quickest to loose moisture in dry weather.  Macro pore space relates to the space in the soil large enough for excess moisture to percolate freely through.

The ability of the soil to hold onto moisture during periods of hot dry weather is largely related to the amount of humus in the soil.  Humus is sometimes referred to as the ‘glue’ in the soil.  It acts as a sponge and has approximately five times the moisture holding capacity of a clay soil containing very little humus.

Humus and organic matter are often confused.  Humus is the result of fully decomposed organic matter and is very stable.   Organic matter is supplied to soil by dead roots, dead leaf matter, dung and urine.  To become humus organic matter needs to be worked on by soil organisms and these organisms require air.

Hence the situations where humus is formed most rapidly is where air is able to enter most quickly and gases to leave freely.  These soils are therefore able to store more moisture and produce the most pasture growth over summer.

With more pasture grown there is more dung deposited along with increased root matter and uneaten pasture to further build humus and stimulate even more growth, and it requires only a little assistance from us.  Grazed soil is regularly subjected to considerable pressure from animals’ feet.  When the effect of this pressure is not relieved compaction occurs and macro pore space is reduced and consequently growth slows.

This can often be fully relieved by an annual application of Golden Bay Dolomite containing 11.5% magnesium and 24% calcium.

Dolomite is unique as it contains calcium and magnesium both in the carbonate form.  Calcium has the ability to force soil particles apart and stimulate beneficial biological activity.  Magnesium adds a little stickiness giving dolomite the ability to increase macro pore space by clumping together very small soil particles.  This process is known as flocculation.

For more information call 0800 4 DOLOMITE, 0800 436 566 or send us an email.

The overall improvement in animal health and performance is less easy to quantify due to the large number of factors that have an influence, however the benefits are just as significant, as an increasing number of farmers regularly applying dolomite testify to.

Golden Bay Dolomite typically contains 24% calcium and 11.5% magnesium and a single application, when applied as part of a well-balanced major nutrient programme, lifts magnesium in a typical pasture to between 0.22 and 0.25%, with the amount of recent direct sunlight and maturity of the plant being influential.

A further benefit resulting from the regular application of dolomite is the improvement in total pasture production due to its positive influence on the physical structure of the soil, particularly the aggregation of soil particles into groups.

The amount of macropore space, the gaps between soil particles and groups of soil particles, has a significant effect on total pasture production as well as the spread of growth throughout the season.

Excess moisture either from rainfall or irrigation needs to be able to percolate freely down through the soil.  When this is unable to occur due to soil having become compacted, activity by beneficial soil organisms will decline and pasture growth reduces.

One of the visual signs of compacted soil, apart from water ponding on the surface, is rapidly changing growth rates.  When all conditions are favourable growth will be very rapid, however as soon as hot dry winds, or colder conditions occur growth rates slow noticeably.

A healthy well-structured soil with adequate macropore space will not only shed excess moisture more rapidly it will also retain more moisture due to steadily increasing quantities of humus being formed, with humus capable of holding 4 – 5 times more moisture than a clay soil with no humus.

Humus also provides storage for essential growth nutrient, and is able to release these, along with moisture to healthy plants helping maintain steady manageable pasture growth.

A well-structured soil also allows pasture plant roots to penetrate to a depth of half a metre, and in some cases a careful examination reveals fine root below this depth.  In these situations both moisture and nutrient from depth is available and although during a prolonged dry period pasture growth will slow markedly,  a higher percentage of plants will survive reducing the need for costly renovation.

Dolomite can be applied at virtually any time and provided sufficient moisture to wash the dolomite off the leaves is likely soon after application, an application in late summer will help provide rapid recovery of pasture once autumn rain arrives.

For more information call 0800 4 DOLOMITE, 0800 436 566.

The reasons “that it’s what everyone else does” or “that it’s the cheapest per kg of nutrient” are inadequate because they fail to answer the question of “what’s in it for me?”

What is important is what you get for your money, and what you get is called performance.  When it comes to magnesium fertiliser Golden Bay dolomite is not the cheapest provider of magnesium, however if the reason for applying magnesium is to limit the number of animals suffering from lack of magnesium, the performance of dolomite is without equal.

Dolomite is also a provider of calcium and this sometimes seems to cause a degree of difficulty.  What dollar value can be applied to the magnesium content, and what value can then be attributed to the calcium content?

The reason animals suffer from calcium/magnesium related metabolic disorders in spring is seldom due to either element being deficient, it is usually the imbalance of calcium and magnesium which is one of the reasons dolomite is so effective.

Dolomite typically contains 11.5% magnesium and 24% calcium.  Soon after application there is a lift in plant leaf magnesium to between 0.22% and 0.25%, with the calcium content of grasses remaining at around 0.60%.

When animals are fully fed on high quality pastures with this balance of magnesium and calcium, and there is sufficient fibre for good rumen function, calcium/magnesium related metabolic disorders are seldom an issue.

Over summer plant available calcium has a major influence on which pasture plants grow strongly and how much total pasture is grown.  Clovers are ideally suited to growth over summer as they thrive on more sunlight and higher temperatures.

Clovers are usually 3 to 4 times higher in calcium than grasses, and being more digestible, animals are able to physically eat and digest more feed and therefore produce more,  gain weight or grow more rapidly.

High performing dairy properties require a minimum of 200kg calcium per hectare per year for optimum performance.   Dolomite applied at 200 – 250kg/ha provides 23 – 29kg magnesium per hectare and 48 – 60kg calcium per hectare.

To provide the extra calcium required for optimum clover and total farm performance requires a further 500kg/ha of high quality ag.lime annually.  When dolomite is applied annually at the rate required to meet magnesium requirements and sufficient calcium is also provided, damage to clover by flea and weevil is minimised.  Yet another advantage!

After a wet winter, in areas where treading damage has been unavoidable, the soil may have become a little compacted with the bulk of permanent pasture roots concentrated in the top 10–12cm.

Where this is the case pasture growth over summer and early autumn will be less than optimum and come in fits and starts depending on the frequency and quantity of rain.

After 20mm of warm rain plant growth may be very rapid only to slow rapidly with the onset of two or three days of warm windy weather.  This puts pressure on pasture management with some operators opting for an open-gate policy on the basis that it may as well be grazed before it turns brown and disappears.

Not all farmers have the same philosophy as well-structured soils allow pasture plants to access moisture from half a metre, or even deeper, resulting in more even growth.  Well-structured soils also have the apparent ability to develop a crust reducing the loss of moisture to the atmosphere while still allowing moisture to be utilised from a lower depth.

A recent field trip to neighbouring dairying properties provided a graphic display of the degree to which soils with different management inputs vary in structure, especially with respect to the amount of granular aggregate and resultant rooting depth of clovers and grasses.

On the property with excellent structure, the outstanding soil characteristic was the amount of aggregate, particularly fine crumb.  The quantity of fine feeding root was also impressive.  There was little sign of root congregating near the surface with an almost even spread of root mass to the bottom of a 25cm spade.  The roots went to a much greater depth, all quite fine and white indicating healthy development over winter.

As the rule of thumb is ‘weight below the ground in root equals weight above the ground in leaf’, the property with the better textured soil will grow measurably more total feed throughout the remainder of the growing season.

It was obvious that the property where soil structures were tighter and root development was closer to the surface, that heavy rain over the last few months had collected in hollows.  Soil in that condition has less moisture holding capacity further limiting potential for summer growth.

One of the differences between the two visited properties has been the use of dolomite.  The property with the well-structured soil has, for close to twenty years, had dolomite applied as the annual input of magnesium, and a portion of the 200kg/ha of calcium.

Dolomite, based on long-term field work, is the most effective magnesium fertiliser available and suitable for application to all soils where, based on soil test data and known usage, there is a need for magnesium.

On ‘heavy’ soils with a high clay or silt content, dolomite helps the formation of initially large aggregates increasing macro pore space, speeding the rate at which excess moisture is able to drain.  On ‘lighter’ soils containing more sand dolomite also helps build aggregate by holding groups of particles together increasing moisture holding capacity.

An annual application of dolomite at the recommended rate provides at least twelve months supply of magnesium and due to the fineness of grinding the response time under good growing conditions is rapid.  Performance is unmatched, it’s local, and the technical support available comes with years of practical experience.

Here in the Rotorua district the December growth figures since 1989 we have give a mean of 60kgDM/ha/day, with a range of 40 – 88kgDM/ha/day.

Figures from Edgecumbe district over the last 7 years show growth ranging from 47 – 86kgDM/ha/day with a mean of 66kgDM/ha/day.  There are long term pasture growth figures for all districts.

Based on this information growth in December is quite reliable and the examination of physical soil structures and rooting depth will further help predictions.

Soil is a living breathing organism and therefore able to respond, often quite rapidly, to changing climatic conditions.   After a prolonged dry period a crust may form on the soil surface, possibly in an attempt to limit moisture loss as it soon disappears after a small amount of rain.

Pasture plants have the ability to send roots to a depth of 0.8m enabling them to access moisture and nutrient from areas usually little affected by our typical short term dry spells over summer.

Recent digging on clients’ properties has shown strong root depth to spade depth (25cm).  The bulk of the root is white indicating that it has formed during winter and early spring prior to the rapid growth phase which starts with soil temperatures reaching a daily minimum of 10°C.

There has been little evidence of roots matted in the top 7.5 – 10.0cm of the soil.  Matting of root usually only occurs if there is hard layer at about 10.0cm.  In some instances if water soluble fertiliser has been regularly applied plant roots may congregate close to the soil surface and this is often accompanied with a hard layer just below.

The ability of soil to withstand the pressure exerted by animal feet is due to the activity of beneficial soil dwellers, predominantly earthworms, bacteria, and fungi.  For these essential workers to provide the assistance necessary there must be sufficient available calcium.

Where excess fertilizer nitrogen is applied soil calcium levels may reduce rapidly with soil pH levels declining to levels of less than 6.0.  Soils may become compacted and unable to provide the moisture and nutrient necessary for strong clover growth over summer.

It is clover that provides strong growth over summer as most pasture grasses only remain in a vegetative stage at soil temperatures less than 20°C.  Above that they become stressed and a seed head supported by a stalk rapidly forms, nearly always occurring in the first week in November.

Calcium is the nutrient most influential in clover growth as clovers are often 3 – 4 times higher in calcium than grasses.

Common to nearly all the properties visited recently is the annual application of dolomite at the rate required to provide magnesium lost to production.  Dolomite also contains calcium, has a stronger pH modifying effect than lime, and is an outstanding conditioner of physical structures.

Some years ago a farmer in the Waikato drafted out his lightest cows in autumn, put them into a large covered shed and fed them almost entirely on kiwifruit.  It wasn’t long before they gained weight and were reintroduced to the main herd without fuss for wintering.

There are cows close to main centres that are fed waste produce from Supermarkets that includes a variety of potato chip type products and a range of confectionary.  Although I haven’t seem them I have it on good authority that these cows perform well by industry standards, with the intriguing part of this story being that a considerable amount of this ‘food’ is still in its wrapper.

Dairy cows that die as result of a calcium/magnesium deficiency or imbalance do so not because their diet is a little deficient, but because their diet is substantially deficient or imbalanced, and unsuited to the animal’s requirements for calving and early lactation.

This is where a single annual application of dolomite can have a major impact.  A single application of 220kg/ha provides 25kg of magnesium and 53kg of calcium per hectare, however it is what results that is important.

The magnesium content of grass as a result of a dolomite application may vary from 0.22 – 0.25% depending largely on the amount of direct sunlight. Leaf calcium content usually measures no less than 0.60% as the calcium and magnesium release at the same rate.

Dairy cows fully fed on grass with this Ca and Mg content receive sufficient to ensure Ca/Mg related metabolic disorders are minimised and production after calving moves rapidly toward its peak, provided rumen function is good.

Now before the calculator is brought out to see whether there is some other way the same amount of calcium and magnesium can be applied by mixing other products together, think about the soundness of the argument that cheapest is best.

Think about your own farm vehicles.  Were they the cheapest available when you bought, or was the main consideration their suitability for the work to be undertaken?  Can the cheapest vehicle be relied on to perform faultlessly year after year?

Soils are living breathing organisms and the health of our animals in spring is a direct reflection of the health of our soils.  Continuing to apply the same soil nutrient package each year, with perhaps minor tinkering, enduring the same animal health problems each spring when there are alternatives that provide largely trouble free calving suggests flawed thinking.

With the present value of quality dairy animals and the increasing payment for fat and protein this is the time to maximise health and performance by applying dolomite, proven to outperform all other calcium/magnesium options.

For those still not convinced, buy 25kg bags of dolomite, empty them into a container where it can stay dry, make it available to the herd each day, observe and monitor.

As that question could not be adequately answered without at least knowledge of current soil nutrient status and past fertiliser inputs the call took some time, with several pieces of extra information providing a clearer picture.

The entire farm had been cultivated in the autumn prior to dairy cows being introduced.  At that stage there had been no known applications of fertiliser nitrogen.  Initially pugging damage was minimal even in extended periods of wet weather, with excess moisture draining freely without ponding

Animal health during the first two springs had been largely trouble free. Calcium/magnesium related metabolic problems had been few, cows calved without difficulty, the occasional mastitis case easily and effectively treated, with somatic cell counts remaining low throughout both seasons.

The third spring had been more challenging with a range of issues requiring extra time and effort.  The number of calcium/magnesium related problems had increased particularly amongst older higher producing animals. The incidence of mastitis also increased with somatic cell counts remaining stubbornly high at times.

Is it possible that all issues are related?  The downward pressure exerted by the feet of heavy animals is significant, and as soils are ideally by volume 25% air, 25% moisture, and 50% solid, compaction particularly in periods of wet weather can readily occur.

Reduced air content reduces the activity of beneficial soil organisms as they rely on a steady interchange of air entering and gas being released.   Under intensive dairying soils will often compact at 75 – 100ml, slowing the ability of excess water to drain freely, with the soil above the developing pan more easily scuffed and pugged.

With plant roots concentrated in the top 100cm, soil moisture content and chemistry rapidly change.  The potassium content in the leaf of pasture often increases significantly during periods of wet weather at the expense of calcium and magnesium, which are more tightly held.

The question of whether compaction is inevitable is then open for discussion.  Under treading pressure soil compresses, compaction occurs when it does not return to its ideal state. This is not inevitable and careful management is required.

When the ideal levels of calcium and magnesium are obtained soils are much less likely to compact.  The ideal levels are best ascertained by soil testing.  In all situations where magnesium is required Golden Bay dolomite is the most effective input.

For an intensive dairy operation a single application of dolomite at 220kg/ha provides 25kgMg/ha, sufficient for one season, and 53kgCa/ha, approximately one quarter of the required annual calcium input.  Due to the fineness of grinding the release of nutrient can be rapid with a marked improvement in animal health achievable within three weeks of application.

Dolomite also has a strong conditioning effect on the soil, increasing the crumb content, reducing the likelihood of compaction occurring and as with all living systems when one aspect of health improves every aspect improves.

I came across a small group of dairy farmers in the Matamata region that claimed to have minimal animal health issues of any type.  The one thing that was common practise amongst this group was that Golden Bay Dolomite was applied regularly to each of their properties.

Their claim was that calcium/magnesium problems were negligible, bloat was almost non existent, as was facial eczema.  I was somewhat puzzled as to how a single annual application of calcium and magnesium could have such an effect on what were perceived to be ailments of unrelated causes.

As farmers our understanding was that each particular illness had a particular cause, they were unrelated and each needed a quite separate treatment, often with varying results.  Our own experience was that even with increasing the amount of magnesium supplemented to stock we needed to remain extra vigilant to avoid unwanted deaths in spring.

Bloat then reared its ugly head just as cows started to reach peak production.  There is plenty of work to indicate that bloat is linked to the potassium:sodium ratio of spring pasture.  Ideally the ratio in a pasture leaf test should be 7:1 or less however it is not uncommon for this ratio to exceed 25:1.

Facial eczema spore counts can vary widely between neighbouring properties, even when subject to the same climatic conditions.  There is a school of thought along with evidence that indicates facial eczema problems are lessened with the regular application of lime.

Perhaps the reason for the group of farmers in the Waikato claiming that annual applications of Golden Bay Dolomite were able to alleviate all these issues is due to its ability to ‘condition’ soils.  Dolomite has the ability to improve the physical structures of soil allowing for better drainage of excess water, more rapid exchange of gasses, and quicker recovery from treading damage.

Soil health improves with better drainage, with plant roots able to grow deeper into the soil accessing nutrient and moisture from lower levels.  Along with the extra calcium and magnesium applied there is probably less luxury feeding taking place near the soil surface where potassium concentrations are likely to be higher.

Dolomite encourages earthworm activity, and earthworms devour dead grass left on the soil surface, limiting the habitat for facial eczema spore.

Just as with any living organism when just one aspect of health is improved all aspects improve.  Every aspect of soil, chemical, physical, and biological, is related and interdependent.  Dolomite supplies both calcium and magnesium, though its primary function is as a magnesium fertiliser.

Being originally a seabed deposit it also contains a wide range of naturally occurring trace minerals.  Dolomite can be applied at any time of the year with an improvement in animal health and performance being reported sometimes within a fortnight of application.

Over a period of several years crop yields declined to the point where it was deemed no longer financially viable to continue cropping and the decision was made to return the area to pasture to be rotationally grazed.

The reason for the decline in yield was not the lack of major growth nutrients, but a steady decline in humus.  Humus is the result of the breakdown, carried out by soil organisms, of plant matter.  The decline of humus resulted from both regular cultivation with soil exposed to the atmosphere for prolonged periods and the probable overuse of soluble fertilisers particularly nitrogen.

My initial visit to the area was three years ago soon after the initial application of a remedial nutrient input programme based on local Golden Bay Dolomite, along with soft phosphate rock and elemental sulphur.

At that time, as it was at the time of the recent visit, there had been a great deal of heavy rain during the month prior.  The soil had been hard underfoot, with few earthworm casts visible and the grass plants were growing with their crowns well above the soil surface.  Although a sand based soil, there were puddles covering a significant area of the paddock.

Now the soil is soft underfoot, and feel is a valid measure when carried out regularly, with the surface almost entirely covered in worm casts, some of which were very large indicating the presence of deep burrowing worms along with others working closer to the surface.

Although recently grazed there were few obvious dung patches and only in the wetter hollows were urine patches obvious.  The soil surface was more than 90% covered in a range of pasture species, all with their crowns close to the soil surface and there were no puddles although there had been heavy overnight rain.

Digging a number of holes to the subsoil depth of about 300mm, a little over a spade depth, showed that the majority of plant roots were going straight down.  Many of the root ends at 250 – 300mm were white and fine indicating they had recently grown, with few darker roots indicating ongoing breakdown of old root mass.

There was no obvious break line at 75 – 100mm depth indicating the soils ability to rebound from the pressure exerted by stock feet.  A truly healthy soil does not compact under rotational grazing regimes where stock are well fed and on areas for a maximum period of 48hours.

A walk to the fence line confirmed our judgement that soil health was excellent.  The stock that were resident in the area and had recently grazed the paddock, were in outstanding health.  Although they could have eaten more, had more feed been offered, they were all large framed animals with dark glossy coats and even without drenching there was not a dirty tail to be seen.

For more information call 0800 436 566 (0800 4 DOLOMITE).