Am I the only one who's wondered what soil test results “look like” in the paddock? It’s my lucky day. Fertiliser guru Doug Edmeades is coming along to our next Wairarapa Farming for Profit field day (3 November at Gladstone). Doug spoke at a recent field day and was such a hit, we invited him back. This time, though, we’re heading out into the paddock. We’re going to take a close up look at pasture to confirm that it looks like what the soil test indicates it will look like.
Essential nutrients
At his last field day, Doug explained that there are 16 essential nutrients that any plant – including pasture – needs. These can come from the air, water, soil or fertiliser. And a plant only grows as fast as the most limited nutrient allows.
Clover tells us a lot about nutrient limitations. We all know that clover equals free nitrogen and great quality stock feed. It also has a high requirement for all 16 nutrients. So poor clover growth tells us there could be a particular nutrient that’s holding it back.
Is your farm nutrient deficient?
Don’t think your farm operation is so good that you’re not affected. It’s estimated that 80 per cent of New Zealand farms are deficient in potassium, phosphorus and/or sulphur (K, P, S).
So what sort of things will we be looking for, when we wander out into the paddock at this field day?
An easy one is prominent urine patches where clover is growing, but has brown margin on the leaves. This can be a potassium deficiency. Lack of potassium in the soil can translate into pasture production losses of up to 40 per cent. That’s a startling figure.
Use available tools
Doug believes most of us can make better use of the tools available. For instance, target productive areas to maximise your return on fertiliser spend. Make use of variable rate applications. Invest in a farm map that shows you different soil types and contours.
His point is that there are a lot of approaches that won’t see you spending more on fertiliser – but, instead, spending your fertiliser budget where you will see the most return.
For more information, email Lauren Cameron
