Double-crop your way forward

Local farmers would do well to emulate the UK’s approach of double-cropping, ecologist Ben Breedlove tells Roelof Bezuidenhout. So, instead of just harvesting a planted crop, why not also slash inputs with beneficial insects, and lure hunters to harvest increased bird populations.

How large an area of your crop land would you leave weedy, if you knew it would cut pesticide costs by 30%? Would you set aside areas within and near your crops to breed your crop pests’ natural enemies? South Africa has unusual crop pests, but an exceptional range of animals and plants can serve as potential pest-control tools for farmers. So says ecologist Ben Breedlove, pointing out that biocontrol has actually received very little attention. “It will become increasingly important in the near future as humans, and their crops, adapt to climate change, expensive petroleum products and rising input costs,” he says.

To cope with new challenges, farms will have to become more efficient and better grounded in technology. And, says Ben, it’s up to the farmer to get onto a learning curve and start developing a different approach to management, even if the information required seems too great for a hands-on manager/owner to process. He insists it’s time to familiarise oneself with concepts such as beetle banks and conservation headlands. These allow farmers to “double-crop”, getting benefits like pest-control, pollinators or attractions for tourists or hunters on top of the traditional crop.

The advantages of ‘double-cropping’
Ben reckons New Zealand has the best record of long-term research on the relationship between biocontrol agents for crop pests and crop productivity. There, strips of land are set aside for breeding those animals which control crop pests. These areas are left uncropped, but by no means weedy. They’re now planned, planted and maintained with as much interest and information as the crop itself.

“These areas are important substitutes for fertilisers, herbicides and pesticides,” Ben explains. “To maximise the benefits that a non-cropped area has for your crop, you need an equal understanding of how both natural systems and non-agricultural natural systems function. But it pays off.” Ben says non-honeybee pollinators, such as alkali bees, are being recognised as major, if not primary, crop pollinators. They’re becoming important as commercial honeybees are increasingly affected by disease and other mortality factors. In New Zealand, lucerne is now produced for alkali bees.

The bees require patches of bare soil to nest, and these areas’ number, size and proximity to the crops are maintained so that pollination occurs as required, whether the crop is being grown for forage or seed production. The bees are one example of goods and services you “establish once and use forever – free.” It also occurs in natural systems and can be linked to and used by human systems.

“On the new kind of farm, cropped and uncropped areas are treated as a single linked system,” Ben explains. “This system produces conventional goods and services for conventional food-related markets, but it also contains biological tools which take the place of chemical inputs.”

Taking beetles to the bank
Beetle banks, notes Ben, are coming into widespread use in the UK. “These are elevated strips across lands that are allowed to regrow to natural perennial vegetation, where predatory beetles can breed,” he says. “The only maintenance they receive is mowing once a year. Initially, there was resistance to converting productive land into a weedy, non-productive mess.

It was widely expected that this would promote pests, and that crop damage would spread throughout the good lands. “But now they’re recognised as an important component of a cropping system that saves the farmer money. Farmers who use them now insist that these highly functional areas be continued. There is also increased interest in determining the effects of size and spacing, and the extent to which pest control is achieved away from the beetle bank and across the cropped land.”

Get ahead with conservation headlands
Ben describes a conservation headland as a 6m-wide strip of unsprayed crop land. The strip is harvested for its crop value with the rest of the land, but pest control isn’t applied within it.  “The intention is to create a habitat for animals living in hedgerows and other strips of natural to semi-natural vegetation next to agricultural lands,” he explains. “In essence, it’s an area where both a crop can be produced and habitat value can be served.”

“Spraying for pest management is avoided during the period when game birds and other wildlife are nesting and raising their young. The birds gain habitat value from this area, and then serve as one of several pest-control agents operating in this zone. The idea of conservation headlands, which seemed too crazy to apply, has now gained acceptance and demonstrated its value.”

Inviting tourists and wingshooters
Increasingly, the primary crop derived from farms in the UK is tourism, including field sports. “Tourists are prepared to pay to see this new side of agriculture,” explains Ben. “UK farmers will tell you they maintain their tractors and chickens to provide a proper experience for their visitors. These implements and animals have no other economic value.” 

“Likewise, more UK apple farmers are producing very few types of apples due to the demands imposed by EU requirements and large-scale food production systems. At the same time, apples from heirloom varieties are being sourced for boutique cider production. Many of the older heirloom varieties simply taste better.

”One specifically appropriate breed of field sportsperson is the wingshooter. Using double-cropping areas to provide habitat for wild birds, farmers can plan and operate a wingshooter’s enterprise while gaining low-cost, low-input pest control and higher productivity from their traditional crops. “That’s three crops produced from a field that only had one in the past,” says Ben.

Contact Ben Breedlove on 012 343 5201 or e-mail [email protected].