Demeter farmer Sjaak Twisk telling his story

In the next few decades, the challenge for Dutch agriculture will be to close the natural circle. Not only to combat soil depletion and the loss of biodiversity, but also to ensure the continued production of a safe and varied range of foods. Demeter’s biodynamic farmers are in the vanguard of this movement, showing exactly how it can be done. Sjaak Twisk, an arable crop farmer from the Flevopolder region, is one of the trailblazers.


‘This is how it all starts.’ At the edge of a field, located in the countryside between Dronten and Biddinghuizen, Sjaak gently pushes aside some wheat stalks to reveal a carpet of blooming clover covering the soil. ‘The clover attracts valuable insects, keeps the weeds at bay and, thanks to its deep roots, loosens up the soil.’ With a broad sweeping gesture, he points to the hectares of wheat and clover all around him. ‘This is our biodynamic gold,’ he says.

In the distance a big combine harvester is already hard at work shredding this dual crop, wheat grains and all. Once fermented in the silage pile, this rich mixture will serve as a high-energy winter feed for the dairy cows, Sjaak explains. ‘During the winter months our cattle are kept in the barn on a metre-thick layer of straw that absorbs their manure. This creates a rich, compacted layer of fertiliser that forms the basis for the growth-promoting preparations that we drive out and spread over the arable land in the spring.’


The stubble field that remains after harvesting the wheat and clover crop is ploughed back into the soil as extra green manure. ‘It’s the ideal soil enricher to grow nitrogen-loving crops like red cabbage or carrots.’ The outer cabbage leaves and carrot leaves are later also ploughed back into the soil to provide fertile ground for vegetable crops like onions, garlic and sweetcorn. These are followed by other crops such as peas, beets, lupin and chicory. ‘During the cycle we switch between deep-rooting crops and more shallow-rooting crops to maintain the natural variation in soil life.’ Seed potatoes are the final stage in the crop rotation cycle in each arable plot. After harvesting the potatoes, Sjaak sows clover on the plot once more and the cycle begins again.

Father and son

Sjaak’s father, potato grower Wim Twisk, was one of the pioneers on the new reclaimed land, first in the Noordoostpolder, then in the Flevopolder. ‘My father was a socially engaged man who did lots of work here in the polder region to get the education and healthcare systems off the ground. In the evenings, after work, he would always be out and about.’ As an arable crop farmer of his own era, Sjaak’s father grew seed potatoes in the rational manner that gained global acclaim for Dutch agriculture in the years after the Second World War. The use of artificial fertiliser combined with pesticides ensured a high degree of efficiency.  ‘The magic word was sterility. The law required my father to chemically disinfect the land of potential pathogens after harvesting the potatoes.’ 

From sterility to biodiversity

In the run-up to the handover over of the business in the early 1990s, Sjaak’s doubts about prevailing agricultural practices were growing. And he wasn’t alone. A study group of young arable crop farmers in the polder region, to which he belonged, concluded that the way in which their fathers farmed was not viable in the long term. Not only for environmental reasons, but also as an economic model. ‘First spraying the soil life to kill everything, then bringing it back to life with artificial fertiliser - that’s what it amounted to in practice. At great expense we would produce huge surpluses and then, supported by subsidies, we would export those surpluses to third world countries, whose farmers didn’t stand a chance.’ Sjaak decided on a change of direction: from sterility to biodiversity. ‘I started farming organically, as it was called back then: growing naturally without using chemicals.’

A mixed farm

Sjaak’s father Wim responded with scepticism: if you want to spend the rest of your life weeding, I won’t stop you. Sjaak was disappointed, but his disappointment was short-lived; barely a week later, Wim changed his mind. ‘He had given it more thought and said: if you want to go ahead with your plans, you’ll also need to start keeping cattle. It’ll have to be a mixed farm like the one your grandfather had. And he was right: you can’t do biodynamic arable farming without animal manure.’ 

Leaving the wheat and clover field, Sjaak drives along a winding series of polder roads to reach the Oostvaardersplassen. From the dyke that separates this nature reserve from the waters of the IJsselmeer, he points out the pastures that he rents from the land managers. ‘Even before the arrival of the heck cattle from Natuurmonumenten [the Dutch society for nature conservation] and Staatsbosbeheer [the national forest service], our beef cattle already grazed here and in the winter we would mow the rugged surface for straw. Two years ago we added the biodynamic dairy farm of a fellow farmer to the existing herd here in the Oostvaardersplassen. Within the business, the circle is now complete. Our combined cattle herds produce the fertiliser we need to enrich the soil and enable the crops to thrive. Then we use part of those crops to feed the livestock.’

Demeter farming

Over the years the Twisk partnership has developed into a sizeable biodynamic producer. It has arable lands at various locations in the polder, two cattle farms and its own fruit orchard.  This Demeter partnership does not have a strict hierarchy. Sjaak is surrounded by fourteen – mainly young – managers who are also part-owners.

From sterility to biodiversity

Focus areas

‘Each manager has their own focus area for which he or she has autonomous responsibility. For instance, Bas is responsible for onion cultivation, Maaike and Gaia run the orchard and Simon is in charge of the dairy farm. They contribute functional knowledge that I don’t have and they experiment with growing crops that I wouldn’t have thought of myself. After all, like my father, I’m basically a potato grower.’ 

That autonomy also applies to the dozens of seasonal workers from Poland and Romania who do the weeding by hand in spring and autumn. ‘Because we pay well, we’ve been working with regular weeding teams for many years who are able to recruit new members in their own villages and regions. By sharing experiences among themselves here in the polder, our seasonal workers know what they’ve got to do and in what order. Weeding takes an enormous amount of effort, but those efforts are rewarded with results.’


Sjaak gets back into his car so that he can show me his favourite spot in the farm. Back in the polder at the edge of Maaike and Gaia’s orchard, he strides into the field before stopping at a makeshift bridge. ‘From this spot you can see what Demeter is all about,’ he says, beaming with enthusiasm like a child. 


Insect hedge

The bridge, made from a pair of old pallets, has been placed over a watercourse that forms the border between the apple and pear orchard on one side and the arable meadow next to it. Along the edges of the watercourse there is a colourful collection of planted hazel, rosehip, wineberries and amelanchier, to name but a few. ‘These hedges attract the insects we like to see in the orchard and flying over the land. These are nature’s protectors of our fruit and vegetables.’ The strips of long grasses mixed with rapeseed in between the rows of apple trees tempt bees and ichneumon wasps deeper into the orchard, says Sjaak. At the other side of the bridge are adjacent plots of onions, peas and sweetcorn which the helpful insects hop across, feeding on pests as they go.

Wonderful and fresh 

The onions were plucked from the ground yesterday, says Sjaak. ‘They look absolutely wonderful. We cut off the onions at the base of the roots then leave them out in the fields for one or two days. That causes the last of the energy in the leaves to drain into the onion, while exposure to the air allows a hard skin to form.’ The sweetcorn nearby is being grown for Machandel. Like peas, sweetcorn is an excellent crop for contract farming, explains the grower. ‘Once the time comes, we start harvesting early in the morning so that Machandel can put the sweetcorn or peas into jars the same day. The fresher the crop when it goes into the jar, the more intense the flavour.’ He pops open a few peapods to allow a taste of the sweet, crisp peas. Sjaak knows that Machandel would also be glad to take the orchard’s entire harvest of sweet-and-sour Evelina apples. ‘But most of it is sold as fresh produce; Machandel turns the rest into applesauce.’