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Wet on top, dry down below

Notoriously wet country looks to better grazing management to solve chronic water infiltration problems

Saskatchewan grazier Neil Dennis figures five centuries of continuous grazing has more to do with the drought affecting the British Isles than a lack of rainfall.

“When you get 70 inches of rain, and the water table is dropping, there’s sure something wrong,” said Dennis, who just returned from a U.K. tour where he had been invited to speak about high-density rotational grazing systems.

A serious drought this spring has led to a ban on new wells and using water for cosmetic purposes such as watering lawns, as the authorities brace for looming water shortages in the island nation of 80 million.

But Dennis said the root causes go much deeper — or rather shallower.

During pasture walks in Devon, Yorkshire and Wales, he saw land where water infiltration has ground to a halt after centuries of grazing too short.

The grass has been pounded by continuous grazing, and never given a chance to fully recover, for so long that the roots underneath barely reach deeper than two inches into the soil. When it rains, puddles form on the pastures because the water can’t penetrate the subsurface hardpan.

“They’ve got no root system under anything and so all their water runs off,” he said. “They are running all their good fresh water into the ocean and the wells are drying up.”

The irony of the situation wasn’t lost on Dennis, who uses a variety of intensively managed grazing practices on his 1,800-acre operation to build up grass species diversity and conserve as much of the 12 to 14 inches of precipitation that falls on his land each year.

He has divided his pastures into small, electrified paddocks with a central alleyway and a buried pasture pipeline for supplying water to the herd.

Judging from posts on farm-related Internet messaging boards, the British stockmen were amazed to hear that he runs up to 1,025 head of cattle on a half-acre for very short periods, and moves his cattle up to eight times per day via solar-powered, automatic gate openers.

“I change what I do all the time,” said Dennis, adding that he sometimes grazes short, tall, or just skims the pasture taking less than half the growth.

The key to his strategy is giving the paddocks enough time to recover and set seed. He has counted up to 40 species appearing naturally via animal impact in a field seeded to only crested wheat grass, as well as wider leaves and greater plant density. Mineral consumption is down 90 per cent.

He has also developed a variation on bale grazing that he calls “deep massage.” First, he hits the area “really hard,” then gives it a full year to recover before putting up to 800 head on a half-acre early in spring to consume the leftover stockpiled grass. Once that’s gone, he rolls out round bales so that the whole area is covered by manure, urine and litter.

The result, he said, is a kind of supercharged topsoil of composting organic matter filled with earthworms that generates its own heat, never freezes deep down, greens up quicker in spring and stays green later in fall.

Unless better grazing practices take hold on the Prairies, ranchers will suffer the same fate as their cousins in England, he said.

“We won’t have to wait 500 years,” he said, with a laugh. “Tiling (drainage) everything and letting it run down the creek — we’re going to create a desert out here.”

David Hugill, who runs an 80-head cow-calf operation on 400 acres in the northeast of England, attended some of Dennis’s talks.

He began trying out managed intensive grazing about two years ago in a bid to extend his grazing season from the traditional October-May to December-March.

In a country where six inches of snowfall is a “disaster,” the cattle are kept in drylot pens and barns to satisfy European Union regulations, as well as to prevent pugging and compaction damage to pastures, as well as nutrient run-off during the winter when it’s too wet to graze. Wintering cattle accounts for 80 per cent of their cost of production.

“There’s a lot of interest now to try and get more root growth, beat the compaction and get more water into the soil,” said Hugill, in a telephone interview last week.

“In certain parts of the country we haven’t got as much groundwater as we’d like to see.”

Constant grazing with no recovery periods has selected only those pasture species that can withstand that onslaught, he added. That has led to very shallow rooting, and as a consequence, poor water infiltration.

After two years of mob grazing, his pastures are drier in parts that were formerly too wet to drive across with machinery during wet times of the year.

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