17 Oct 2022

‘Organic strip cropping results in stable yields’

Better risk management, more biodiversity and reduction of pests and diseases – these are just some of the benefits of strip cropping. A number of organic farmers are putting this new cultivation method into practice in the Netherlands. One of them is agricultural company Erf BV, on one hundred hectares. The method is being trialled in other European countries too. “It results in more stable yields with the same amount of labour. But it also requires extra knowledge and a different approach,” says Dirk van Apeldoorn, lecturer and researcher at Wageningen University & Research (WUR).

Van Apeldoorn has been conducting research into strip cropping in the Netherlands since 2014. It entails dividing a field up into strips according to the width of the farm machinery such as 3 or 6 meters or a multiple thereof. A different crop is planted in each strip. “Strip cropping is similar to the traditional farming method in China, and in the 1960s it was used in the USA for maize and soybean,” states Van Apeldoorn.

In the Netherlands, one aim of strip cropping is to help organic farmers achieve more stable yields, explains Van Apeldoorn: “For example the mushroom Phytophthora can ruin a whole field of potatoes. Strip cropping helps to stop it spreading.”

 

Risk management and biodiversity

The findings from many years of research show that this really does work in practice. The crop diversity helps to limit the risks and prevents the failure of an entire harvest of a monoculture. Moreover, planting the right combination of crops can reduce the pressure from certain pests, according to Van Apeldoorn: “Aphids are harmless to corn, for example. These attract spiders, beetles and wasps, which then form a ‘army’ for the adjacent strip of cabbages, for example, which are susceptible to damage from aphids.”

Research confirms that strip cropping increases biodiversity, that it attracts many different species of insects as well as birds.

More stable crop growth and business benefits

Roy Michielsen, a grower at Erf BV, can confirm the abovementioned advantages. Erf BV leases 1,500 hectares of land from the Dutch government and is the biggest organic farming company in the Netherlands. He cultivates 15 crops based on a 1:8 rotation cycle and supplies his products to major supermarkets and processing companies. In collaboration with WUR, Erf BV has been putting strip cropping into practice since 2017 – initially on 40 hectares, which has since increased to 100 hectares.

Michielsen: “We organically grow potatoes, onions, oats, celeriac, parsnips/carrots, broccoli, grass/clover and broad beans in strips measuring six metres wide and 500 metres long. Because we work with both strip cropping and monocultures, we are in a good position to compare the two approaches. In our experience, strip cropping leads to stable plant growth. With an increase in beneficial insects – especially in potatoes – there are fewer problems with Phytophthora. From a business perspective, strip cropping is comparable with a monoculture in terms of both yields and costs. Although our employees were a little skeptical at first, they are all enthusiastic now. The simple fact is that it works well and it looks great.”

Complex puzzle with crops and varieties

Of course, strip cropping is not without its challenges. First and foremost gardener need a lot of knowledge to choose the right crops. Michielsen: “It’s a puzzle that requires thorough planning. That was very time-consuming for us at first.” Van Apeldoorn adds: “The system is quite complex. The gardeners have to make the right combinations.

Different crops, and even different varieties, can react to one another. That places extra demands on the Producers skills. Incidentally, lots of vegetable crops are suitable for strip cropping, including cabbages, pumpkins, leek, carrots, lettuce and spinach. In the Netherlands we’ve developed a course as part of the Bioacademy to help growers to make a crop plan. Unfortunately there’s nothing similar on an international level yet.”

GPS essential

Besides knowledge strip cropping also requires the agricultural company to take a different approach, Michielsen has discovered: “Ploughing doesn’t work with this system. Our strips are six meters wide, so we can use almost all of our regular machines – providing that the tractors are fitted with GPS to support precision sowing. Besides that, water-reel irrigation isn’t ideal, which is why we switched to drip irrigation in 2020.”

More difficult to harvest root and tuber crops

He explains that it is more challenging to harvest celeriac, carrots and potatoes in strip cropping than in a monoculture. “We use the same machinery as for our monocultures, which means that we sometimes have to drive the tractor over the adjacent strip. That requires careful planning in terms of harvesting the crop in that adjacent strip. We’re currently managing to harvest all the crops, but we could further optimize that if we had different machines.”

Research projects in Europe

Strip cropping can be summed up as offering opportunities but also presenting some challenges. Van Apeldoorn firmly believes that the system will gain ground in the organic sector and also in traditional farming, both within and outside of the Netherlands. “The Netherlands is leading the way in strip cropping because the issues related to biodiversity and tackling pests and diseases are more urgent there than elsewhere. But some growers in Belgium have started using this strip cropping system, and we’re also involved in European projects in Denmark, Sweden, Germany, Austria, Italy and Switzerland. Of course, each project is adapted to the local conditions in terms of things like crops and strip width.”

“I believe that we need to transition to a different agricultural system: a robust, plant-based system with more crop diversity and more biodiversity. Strip cropping doesn’t have all the answers, but it does offer growers the chance to make a start.”

Would you like to know more about strip cropping?

Film – Strip cultivation in the experimental garden – Wageningen University & Research

Weblog – More nature in fields through strip cropping – Wageningen University & Research

Quotes:

“Aphids are harmless to corn, for example. Those aphids attract spiders, beetles and parasitoid wasps, which then form a ‘standing army’ for the adjacent strip of cabbages, for example, which are susceptible to damage from aphids.”

“Lots of vegetable crops are suitable for strip cropping, including cabbages, pumpkins, leek, carrots, lettuce and spinach.”

“I believe that we need to transition to a different agricultural system: a robust, plant-based system with more crop diversity and more biodiversity. Strip cropping doesn’t have all the answers, but it does offer growers the chance to make a start.”