'Conventional plough could contribute to famine'

Photo: Cross Slot no tillage drill

A New Zealand agricultural scientist slash machinery manufacturer claims conventional ploughing could contribute to famine because it causes high rates of carbon loss from soil.


Dr John Baker, has a MAgrSc in soil science and a PH.D in agricultural engineering, which these days are mainly deployed in the manufacture and sales of his Cross Slot no-tillage seed drills. His 'famine' claim is stretching it, and he obviously has a vested interest in this, however, he makes a valid point about carbon loss.


He says carbon is lost to the atmosphere through conventional ploughing and that studies show 15-20% of CO2 in the atmosphere comes from annual ploughing.


Vital ingredient
Carbon is a vital ingredient of soil, Baker notes. 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. Fair enough.


“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,” Dr Baker says.


“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.”


Key-hole surgery
After 30 years of research at Massey University, Dr Baker researched and developed Cross Slot no-tillage drills which penetrate through crop residue on top of the ground and simultaneously sow seed and fertiliser in adjacent bands.


The no tillage 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. 


Food Prize
This year Dr Baker was nominated for the World Food Prize, which was announced last month at the State Department in Washington. Someone is taking his no tillage message seriously.


He points out it’s incredibly important for the soil to gain and trap carbon “if we’re to feed the 50% 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.”


Fuel costs: a net gain
Dr Baker also claims no-tillage saves up to 80% of a farmer’s fuel costs in establishing crops and pastures. Typically no tillage drills are harder to pull through the ground and therefore require a more powerful (and less fuel efficient) tractor. However, no tillage requires fewer passes by the tractor; Baker says farmers typically use 50 to 90 liters of diesel per hectare during the multiple times required to establish a crop. By comparison no-tillage uses “10-20 liters per hectare”.


Dr Baker says that New Zealand farmers sow about one million hectares of new seeds each year. Recent Massey University research suggests that if low-disturbance no-tillage was used universally to sow these seeds it would result in about 1.5 million tonnes less CO2 discharged into the atmosphere annually.

Wanted: Drought resistant crops

With over 60% of continental US suffering drought it is perhaps no surprise Purdue University is promoting its work to find drought-resistance genes.

The search for these genes is focusing on tropical varieties of corn; the genes would be transferred to American corn varieties along with the drought tolerance they confer on plants. The desired equation is simple: maximum yield for minimum water use. As such, it is likely the most useful genes will be related to the control of transpiration -- the opening and closing of stomata on the leaf surface.

Meanwhile, the US droughts are forcing authorities to open up protected land to help farmers feed stock. Agriculture Secretary Tom Vilsack has authority to open up land under the voluntary Conservation Reserve Programme for emergency grazing.

According to US Drought Monitor data, 88% of US corn and 87% of US soybean crops are in drought-stricken areas. Global grain prices have soared over recent weeks.

No surprises in FAO's food security summary

While international agricultural commodity markets appear to have entered calmer conditions after record highs last year, food commodity prices are anticipated to remain on a higher plateau over the next decade, underpinned by firm demand but a slowing growth in global production, according to the latest OECD-FAO Agricultural Outlook.


The report suggests that in addition to population growth higher per capita incomes, urban migration and changing diets in developing countries, as well as rising requirements for biofuel feedstocks, are underpinning demand pressures. At the same time, agricultural output by traditional exporting developed countries has been slow to respond to higher prices in the last decade.


Higher demand will be met increasingly by supplies that come to market at higher cost. With farmland area expected to expand only slightly in the coming decade, additional production will need to come from increased productivity, including by reducing productivity gaps in developing countries, the report said.


The Outlook anticipates that agricultural output growth will slow to an average of 1.7 percent annually over the next 10 years, down from a trend rate of over 2 percent per year in recent decades. Higher input costs, increasing resource constraints, growing environmental pressures and the impacts of climate change will all serve to dampen supply response.


Much of the projected growth will come from developing countries, which will increasingly dominate in the production of most agricultural commodities, and also take on a more important role in commodity trade.


"Increased productivity, green-growth and more open markets will be essential if the food and nutrition requirements of future generations are to be met," said OECD Secretary-General Angel Gurría. "Governments should renounce trade-distorting practices and create an enabling environment for a thriving and sustainable agriculture underpinned by improved productivity. We have highlighted many of these issues in our work on food security for the G20 and this Outlook provides further important analysis and recommendations to governments."