Soil matters with Peter Burton Functional Fertiliser Ltd

There are differences between farms. Size and contour vary, as does the type and number of animals grazed. However, whether dryland or irrigated, there is one constant – the necessity of nitrogen for pasture growth.

The air we breathe is 78 per cent nitrogen, so there is no shortage. A limitless resource can be taken for granted, particularly when there is no cost, as we tend to value only stuff we have to pay for.

An abundance of plant-available nitrogen is essential for profitable farming and many pastoral farmers have opted to buy it on a regular, even monthly, basis while others seldom if ever do.

Those not purchasing nitrogen ensure they have enough to meet their requirements by appreciating that clover fixes nitrogen, and manage and fertilise their pastures accordingly.

That knowledge and those skills have been passed down since long before the time when urea became readily available. That started in the late-1980s and therefore its widespread adoption is relatively recent.

The amount of nitrogen that can be applied is 190kgN/ha/year, which is 40kg less than the average on intensive dairy farms. Some farmers will already be figuring out how to lower their inputs, while others are trying to decide if they can cut it out completely in contemplation of a steadily sinking lid.

Many of the farmers using clover, and clover alone, to supply their nitrogen requirements are not ‘organic’, and are growing more pasture annually than their neighbours, and have been for at least the last 20 years.

Higher feed value

One of the other reasons for potentially superior farm performance is the higher feed value of clover relative to grasses particularly from November to May.

The calcium content of clover is often two per cent and as high as 2.5 per cent when fully mature. Grasses typically contain no more than 0.6 per cent – which is one-third to one-quarter of a healthy clover plant.

Farmers dependent on fattening lambs appreciate the fact that lambs fatten most rapidly on a clover-dominant pasture.

Calcium is a requirement for bone growth and clover contains calcium that is immediately available for frame growth due to its digestibility, particularly during late-spring and summer; the period when young animals grow most rapidly.

The time that an animal spends grazing is distinctly hereditary. Even when presented with extra high-quality pasture the grazing time does not greatly increase and therefore total intake is highest when feed is most digestible.

Energy is an important factor, and at almost any time during the year animal performance lifts with more energy in the diet.

Soluble sugars

Clover nearly always contains more soluble sugars as measured by a refractometer, a hand-held easily operated device that provides valuable real-time data.

Soluble sugar levels are lowest overnight and first thing in the morning. As sunlight increases, the energy (brix level) of pasture lifts peaking usually in early afternoon.

Clover and bloat are often linked in people’s minds, with good reason. However, that doesn’t have to be the case.

Bloat is often related to feed rich in potassium relative to sodium, and extra fertiliser potassium is not recommended unless soil and leaf tests show pasture growth is limited by a lack of potassium.

Extra calcium in the form of lime provides the calcium necessary to grow large-leafed long-stemmed clover that animals thrive best on. And because clovers naturally contain little sodium, having salt available will further reduce the likelihood of bloat.   

Functional Fertiliser developed the product CalciZest 20 years ago, which contains lime, soft carbon and a wide range of selected beneficial fungi and bacteria.

CalciZest is often applied at this time of the year at 300-400kg/ha through conventional groundspread equipment, or by aircraft, to ensure optimum clover growth during summer and autumn.  For information on grazing management, call Peter on 0800 843 809.