Making Dollars and Sense of Nutrient Management

April 2006
During March, Dexcel and Fonterra Milk Supply presented a nutrient management road show series with 36 on-farm field days being held throughout the country. These field days gave farmers tools to save money and improve their farm system efficiency as well as focusing on local environmental issues.

Fertiliser is typically about 15% of dairy farm working expenses and is usually a farms biggest cost. The large variation in fertiliser spending between farms suggests that a lot is unnecessary since most farms have good soil fertility.

Much of the nutrient applied to soil is lost to the environment, and that represents a loss to the farm business and a burden on the environment. By understanding the nutrient inputs and outputs to a farm, farmers can take steps to save money and protect the environment.

Roger Hunt is one farmer who has taken a keen interest in the nutrient status of his property.

I started because I had animal health issues, bloat and metabolic problems that came from high K in the soil and plants. I sought advice, and now I take a holistic approach to the soil, check for good noduling on clovers, a healthy worm population, and look at plants and stock looking for signs of problems, says Roger.

The farm has two soil types peat and clay and they have to be managed differently. I am very aware of avoiding a build-up of K in the areas where we irrigate effluent, particularly on the clay. I use regular soil test to monitor nutrient and trace element levels.

Soil and herbage tests have shown that the clay hills and the effluent irrigated areas need very little fertiliser only lime and a small amount of trace elements. Some of the effluent irrigated areas were high in N and K, particularly on the clay soil, so usually Roger mines that by growing maize on those areas.

He finds using Overseer, the nutrient budgeting program, is a great aid to nutrient management. It allows him to take into account maize silage brought in as well as the fertilisers, and he now has a good understanding of the inputs and outputs on his farm.

Environmental actions to avoid wasting nutrients and the possibility of polluting waterways, Roger has taken a number of precautions:

Keep away from drains when spreading fertiliser

Have a buffer zone between drains and the areas being irrigated with effluent

Have an irrigation map that shows where the irrigator travelled in the last round so that it doesnt get put in the same place on the next round, and so there is no excessive build-up of K in one area.

Fencing off drains

Keep young stock and springing cows off high K areas

In addition, Roger has planted a woodlot in an area that was always damp, and planted trees all along the race to give shade to stock in summer as they walk to and from the cowshed.

Sorting out the nutrient status of his pastures has also meant better stock health no more bloat.

As a stockman my No.1 priority is for the animals, and now that we have the nutrient status sorted I can sleep at nights, he says.

The most important thing I believe is to monitor everything carefully and put on only the fertiliser that you need, otherwise it is just money down the drain. Use the tools that help you to save money on fertiliser and also on animal health.

Dexcel and Fonterra have produced a detailed booklet, 'Making Dollars and Sense of Nutrient Management - 7 steps to success', which is a practical guide to developing a sustainable nutrient plan, and carrying it out. It gives lots of detail on soil and herbage tests, and what they mean, deciding on the amount and type of fertiliser needed, timing of applications, nutrient budgeting, and many other management considerations.

Copies are available from any Dexcel consulting officer or from the Dexcel website www.dexcel.co.nz.