Agriculture and Agri-Food Canada

Agriculture and Agri-Food Canada

April 17, 2008 13:01 ET

Stones in the Field Don't Have to Put Farmers Between a Rock and a Hard Place

OTTAWA, ONTARIO--(Marketwire - April 17, 2008) - Stones buried in potato fields are a fact of life for potato growers in much of Atlantic Canada. They come in all shapes and sizes ranging from gravel to rocks. These buried boulders can lead to excessive wear, breakage, and down-time of field machinery and injure potato tubers during mechanical harvesting.

In some regions, the problem with stones is so great that specialized airvac harvesters have been used to mechanically separate potatoes from stones during harvesting.

But these stones have their place in protecting soil from erosion and helping plants grow by aerating the soil and keeping heat and moisture in the ground.

Agriculture and Agri-Food Canada researchers in Fredericton have found there is a solution that doesn't put farmers between a rock and hard place. Studies show that mounting a rock crusher on the back of a harvester can crush troublesome stones into fragments that are easy on farm equipment and potatoes and good for the soil.

Crushing stones

Simply removing stones from a field significantly reduces the ability of the soil to absorb water after a rainfall and increases soil compaction. That, in turn, increases surface runoff and soil erosion.

Coarse rock and stone fragments on the field have the same effect as other mulching materials in protecting the soil against the impact of raindrops, while helping to keep heat and moisture in the soil and improving crop yields.

By replacing the stones with crushed pebbles that are about 2.5 centimetres in diameter, erosion and runoff is greatly reduced. At the same time, the pebbles don't get thrown into the harvested potatoes, saving the crop from damage.

In the New Brunswick studies, 38 per cent of potatoes were damaged under regular field conditions. A rock crusher reduced that damage to 17 per cent and lowered the possibility of injured potatoes rotting in storage.

Until now, some farmers have been using front-end loaders to physically put stones back in the field. However, a number of rock crushers incorporated with potato harvesters are now available commercially in New Brunswick at an average price of between $30,000 and $35,000. The stone crusher has also triggered interest from farmers in other regions of Canada where excess stones are a problem.

It's a significant investment, but researchers say the payoff will come in larger potato crops and more potatoes that make it to the marketplace, healthier soil, less erosion and fewer equipment repairs - and the satisfaction of turning a rock-hard headache into pay dirt.

Contact Information

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