An international soil scientist claims that, too often, New Zealanders treat 'soil like dirt” when it should be revered because 'our lives depend on it”.

Dr John Baker is trying to get people to realise that soil is an important part of human life.

Dr John Baker says human life exists because of soil yet all that most people do is walk on it, dirty their shoes or dig it up and put buildings and roads on it.

'Soil is a living entity. It provides us with up to 90 per cent of our food. There are more living organisms in a cupful of healthy soil than people on the planet.”

John says alarming figures provided by the United Nations Food and Agriculture Organisation (FAO) and the UK Farmers Weekly suggest that the quality of soil is rapidly diminishing.

FAO predicts the world, on average, has just 60 more years of growing crops left while the Farmers Weekly claims that only 100 harvests remain in the UK.

John says New Zealand's rotation of arable crops and pasture land gives us more time but many arable farmers both here and around the world are still unknowingly but progressively destroying the soils.

'Eventually crop yields will decline to the point where the world's ability to feed its ever-increasing population will be compromised,” he says.

'Crunch point is expected to be about 2050 by which time there'll be famine in some developing countries.”

John's comments are in line with the US Senate, the FAO and he's twice been nominated for the World Food Prize.

However, when he took his case to parliament's Primary Production Committee this year, he was told it didn't relate to any items of business currently being considered by the committee.

He says because soil isn't sexy, 'is not on our radar and is metaphorically beneath us”, it's taken for granted by many farmers and ignored altogether by politicians and city dwellers.

'On the other hand there are notable farmers here who value their soil and have stopped ploughing it. Instead they use low disturbance, no tillage to establish crops and pastures and, in the process, are rebuilding their soil organic matter levels and increasing yields,” he says.

Ploughing kills off earthworms and micro-organisms which are an integral element of healthy soil, it oxidises carbon that's already in the soil and releases it as carbon dioxide into the atmosphere and contributes to crop failure and soil erosion.

John, who has a MAgrSc in soil science and PhD in agricultural engineering from Massey University, has long advocated the use of low disturbance, no-tillage.

The process, which penetrates through crop residue or vegetation on top of the soil and sows seed and fertiliser in separate bands beneath it, causes minimal disturbance to the soil, traps the humidity, preserves the organisms and soil life, largely prevents carbon from escaping and increases yields.

John's own Cross-Slot no-tillage drills are sold in 18 countries and used extensively in the US and Canadian plains, in Australia and the UK.

'The irony is that New Zealand has the best technology for rebuilding soil health yet we're falling further and further behind the rest of the world where the use of ploughing is declining in favour of low disturbance no-tillage machines,” says John.

'The UN General Assembly has declared 2015 as the International Year of Soils. If we stopped being complacent we could lead the world in conservation agriculture but it requires recognition and an innovative approach from our politicians before it's too late.

'The clock is ticking on how many harvests New Zealand has left.”