Soil matters with Peter Burton Eco-logic Soil Improvement Ltd

We’re all aware nitrogen is one of the essential elements to get plants to grow.

What some farmers don’t seem to realise is there is already tonnes of it in our soils, not to mention being a major part of the air around us. The only hitch is this soil or air nitrogen needs help from nature to make it suitable for plants to use.

And the help could come from those mycorrhizaL fungi and bacteria we keep banging on about, which do the trick of turning the soil and air nitrogen into plant usable forms.

In the late 1970s, before we started on the ‘urea track’, our scientists had estimated there could be a reservoir of up to 14,000kgN/ha, with between 3400kg and 6800kg of organic N/ha in the top 150mm of soil.

But if the soil life isn’t there, or not in sufficient quantities, then all that “free N” can’t be got at by plants. The answer should have been to boost the soil life and let nature get on with it. But what happened was the chemists came up with a great money-making idea, and produced urea, and the big fertiliser companies leapt at the chance to sell a product which they could encourage farmers to use all the time.

Nitrogen for free
What we are now hearing from farmers is “you can’t grow grass without urea”, and they believe it. How do they think grass grows in places where urea hasn’t been spread?

And it’s not just this misperception going around. Regular urea applications tend to decimate the very mycorrhizae and bacteria which could and should be doing the job. Not only this, but the clover plants, which used to be part of the process in fixing nitrogen for free, now get discouraged by the constant urea dumps, and give up on doing their job.

We pride ourselves on growing ryegrass/clover pastures, but how much clover can still be seen in many of them? It’s got tired of not being able to do what it does best, and faded away.

What our pastures really need is sweetening up with regular calcium (lime), trace elements applied where soil tests have shown shortages, and mixtures enhanced with carefully chosen mycorrhizae and bacteria to help the soil life that’s already there.

Urea is expensive to make and uses a lot of energy to do so. Even with discounts it costs a lot to buy and spread. When the milk price crashes, and budgets don’t add up, it’s a farm expense most could do without.  

Add to this growth tests are proving we are now producing less kgDM/ha in pasture than we did in the mid-1980s, despite using up about 750,000 tonnes of urea per year, most of which goes on dairy land. That’s about 200kgN/ha (440kg of urea), and probably more in some places.

Copious soil life
Functional Fertiliser Ltd has been measuring dry matter growth levels on several farms using its products for more than a decade now. And these levels are getting bigger every year, with recent measures showing more than 100kgDM/ha growth every day in January.

No added N, as tests have proved there is already about 9400kgN/ha in the top 300mm of the soil – the depth to which plant roots can penetrate freely. Just lots of calcium, trace elements where needed, and copious amounts of soil life.

When the payout looks like never recovering, and the need is to keep production high, why spend the precious budgets on something you don’t need? When you could be spending it on something really useful that makes low-cost, highly-nutritious grass grow?

And the prize to top it all off is you could soon be leaching up to 70 per cent less N into our streams and groundwater. Solving two problems in one go.

For more info, call Peter on 0800 843 809.