LEEK GROWER ROBIN PEETERS: HEALTHY SOIL, ROBUST VARIETIES KEY TO SUCCESS
‘ORGANIC NEEDS TO CONTINUE TO STAND OUT’ WEEDS ARE A CHALLENGE. BUT PAYING ATTENTION TO HEALTHY SOIL AND ROBUST VARIETIES CAN HELP TO CONTROL FUNGI AND INSECTS. THAT’S BEEN THE EXPERIENCE OF THE DUTCH GROWER ROBIN PEETERS, WHO PRODUCES LEEKS AND LEEK PLANTS. The smell of fresh leeks is always in the air at the Peeters-Mertens organic market garden in the Dutch village of Neer. Robin Peeters and his parents, Ellen and Wim, prepare a shipment nearly every day. They fill orders for a number of organic supermarkets through the Nautilus cooperative. Leeks are one of the main crops at this family farm in the province of Limburg. They produce vegetables year-round, Peeters says, and planting begins in March. “We start with super seedlings [plug plants] from Morocco in week 8 or 9. From week 17, we plant Dutch greenhouse plants, and from about week 20 we move on to individual field-grown plants.” Planting continues until week 29, in late July. They start harvesting in the second half of May and don’t stop until the following April. “In the last weeks, we put some into cold storage to tide us over until May,” Peeters says.
Fungi and insects The family has more than 20 years of experience as organic growers. Peeters’ parents converted the farm in 2000. “In the early days, their main worry was that fungi and insects would become an issue if they had to stop spraying,” he says. “But it turned out to be fine. Weeds are a challenge, though.” Because of weed pressure in the sandy Limburg soil, the farm can’t avoid inversion tillage. Peeters regrets that. “You actually don’t want to plough at all because of the soil life,” he says. “We do it, but as shallowly as possible, to 20 centimetres. An eco plough is on our wish list.”
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The soil is the most important success factor, according to Peeters. Since making the switch, the family has embraced organic matter. They use plenty of compost and straw manure. “In 20 years, our organic matter content has risen from 2 per cent to 2.7 or 2.8 per cent,” Peeters says. “That might not sound like much, but it makes a huge difference for the growth of the crop.”
Annual soil tests The growers get the soil sampled every year. “We mainly look at the proportions of the minerals,” Peeters says. “Balance is more important than quantity. You see it with potassium, for example. Since we use a lot of compost and cattle manure, we add quite a bit. An excess can cause problems with magnesium and calcium uptake.” The family uses nitrogen sparingly. Too much nitrate-nitrogen makes the crop more susceptible to pests such as thrips, Peeters says. So, while in conventional cultivation it’s usual to use 250 to 300 kg, he keeps it down to 150 kg at most. “We aren’t going for a yield of 60 tonnes per hectare. We do get 40 tonnes, and we use a lot less input to get it.”
Rotation On conventional farms it’s usual to grow leeks on the same field year after year. As Dutch farmers say, “Leeks make leeks.” Peeters favours a three-year crop rotation plan. He starts with
