Clean technology: Keyhole surgery for the soil

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This is the Cross Slot No Tillage system, developed here in New Zealand by Dr John Baker, who has a MAgrSc in soil science and a PH.D in agricultural engineering, and has tinkered away on his invention for 30 years.

Baker has a stark warning for us if we continue down the path of traditional horticulture, predicting that if conventional ploughing isn't replaced by low-disturbance no-tillage within 50 years there'll be famine in large areas of the world.

Baker says it's imperative that carbon remains in the soil and is not lost into the atmosphere through ploughing. He says studies show that 15-20% of CO2 in the atmosphere comes from annual ploughing around the world.

Carbon is a vital ingredient of soil. Plants that we eat all contain carbon.

When they die they decompose and earthworms and other microbes take the products of decomposition, which are rich in carbon, into the soil and keep them there.

"When the soil is ploughed it releases much of the carbon back into the atmosphere. The long term result is a reduction in soil organic matter, which in turn leads to soil erosion, dust storms and ultimately famine," says Baker.

"Ploughing takes away the food sources of microbes that hold the soil together. Organic matter also stores water and the loss of both decreases the crop yields."

From 30 years of research at Massey University, Dr Baker decided there had to be a better way of sowing seeds.

He researched and developed Cross Slot no-tillage drills which penetrate through crop residue or vegetation on top of the ground and sow seed and fertiliser in different bands at the same time.

The Cross Slot process causes minimal or low disturbance to the soil, traps the humidity, preserves the micro-organisms and soil life and largely prevents carbon from escaping into the atmosphere. Further, by leaving the stubble and straw from the previous crop to decompose on the surface of the ground, it helps sequester new carbon into the soil.

No-tillage is the equivalent of keyhole surgery as opposed to ploughing which is invasive surgery and contributes to global warming. The result of no-tillage is increased yields and the near elimination of crop failure and soil erosion.

The end result is sustainable food production which can feed millions of people.

This year Dr Baker was nominated for the World Food Prize, which was announced recently at the State Department in Washington, and his nomination carries over to 2013.

He points out it's incredibly important for the soil to gain and trap carbon "if we're to feed the 50 percent extra population in the world by the year 2050."

"Only four percent of the world's surface has arable soil and we have to learn to farm it sustainably which we simply haven't been doing. That means no-tillage must replace ploughing as the mainstream food production technique."

New Zealand farmers sow about one million hectares of new seeds each year.