Stephen Briggs scans the horizon where dark clouds are looming. He finished the grain harvest the day before, but the straw still needs to be baled and he’s not keen on rain just yet. But it does look as if a thunderstorm is heading our way, the wind has picked up and suddenly drives a cloud of dust towards us – it’s the soil from a neighbour’s field that has just been ploughed, explains Briggs. “Look at that,” he says, “that’s why I have planted all those trees.”

Whitehall Farm lies just south of Peterborough; the land here is flat and the soil fertile. In 2007, Stephen Briggs and his wife Lynn were chosen from out of 85 applicants to be the new tenants of this 102 hectare Cambridgeshire County Council farm. Normally a tenancy is up for renewal every three years, not a good option for the Briggs who wanted to switch to an organic farming system. However, the landlord got behind the idea and granted them a 15-year tenancy, which has just been renewed for another 15 years.

Neither Stephen nor Lynn Briggs come from farm families. Stephen’s background is in engineering. When he found out he didn’t particularly like his job in the car industry, he decided to retrain. He studied agriculture, did a Master’s degree in soil science and eventually used his Nuffield scholarship to research agroforestry. Lynn, too, is a soil scientist.

“Everyone said it would be impossible to manage this farm organically and make a profit,” says Briggs to whom increasing, improving and investing in soil and carbon are key. Previous tenants had grown wheat, oilseed rape, sugar beets and potatoes continuously for 40 years. “The soils were very, very tired, which is a polite way of saying they were knackered.” Strong winds are common in the area and preventing soil erosion was top on the Briggs’ list of priorities. Rows of trees are ideal windbreakers but planting them in the middle of a corn field could potentially cause quite a few problems. That may be one of the reasons why silvopastures – trees planted on grazing land – are much more common than silvoarable systems – trees on arable land. Sheep or cattle can easily move around trees, with a tractor or a combine it’s a lot harder.

After Briggs got permission for the tree project from the landlord, he had to design the system. He decided to plant apple trees on semi-dwarf rootstock because such trees don’t grow too high and they provide a financial return in a relatively short time – which is important for a tenant farm. Apples also add good value, for example, by producing apple juice.

In 2009, Briggs converted 56 hectares – half the farm – into a silvoarable system by planting 4,500 trees in 45 northeast/southwest facing rows. The strip under the trees is exactly 3 metres wide. The alleys between the rows of trees where the arable crops can be grown, measure precisely 24 metres. All of Briggs’ machinery is 6 metres wide and operated on tramlines in a controlled traffic system, and because all the machinery has the same width, the same wheel tracks can be used. Once established, the tramlines – or permanent wheel tracks – protect the trees and prevent the compaction of other parts of the field.

Briggs chose 13 different apple varieties: six heritage varieties, six modern ones and Bramleys for cooking. The trees were planted into a geotextile layer to supress weeds. “‘It seemed like a good idea at the time. In hindsight, I wish we hadn’t done it, we are learning the hard way,” says Briggs; the geotextile is providing ideal living conditions for mice and voles. But there is an upside: the five nesting boxes for barn owls are all occupied, probably thanks to the smorgasbord the owls find among the trees when the rodents come out at night.

All trees were planted next to a 60 millimetre post and surrounded by a wire guard. The initial cost for the silvoarable project including infrastructure was £65,000, which explains why Briggs didn’t plant trees on the whole farm: it would have been too expensive.

By now the trees are mature enough to produce apples. Seasonal workers are needed for the hand-harvest. Throughout the year some maintenance work has to be done: pruning, mowing the grass under the trees and training the roots to grow down by cutting to a depth of about 25 centimetres along the edge of the grass verge. The tree roots need to grow deeper, otherwise they might hinder the root development of the annual grains which will be planted in the alley between the rows. The grains benefit visibly from the tree mycorrhiza that extend into the crop area. Briggs says the grains growing closer to the trees develop a little bit better and faster than those in the middle of the alley that the mycorrhiza don’t reach.

As positive as it all sounds, the £65,000 investment is a lot. Are the trees worth it? They definitely are, says Briggs, and because trees grow on only half of the farm, he can make a direct comparison. The arable yields per hectare are the same and the trees only take up 8% of the available space. If he can press the apples into juice, the trees are as profitable as wheat or oats would be on the same acreage.

Growing two crops instead of one is a good insurance policy – in a year in which wheat or oats aren’t doing well or prices are low, he still stands a chance to make a good profit from the apples, and vice versa. “I pay rent for every acre of soil,” says Briggs, “the space above is free; I might as well use it. Trees take farming into the third dimension.” Still, this year the apple harvest has been dismal. A number of factors are to blame, says Briggs: the beekeeper who stationed his hives on the farm fell ill and there were noticeably fewer bees in spring. There was too little rain and the trees suffered drought stress; there were some nutritional issues and he had too little time to do a good job at pruning. This isn’t surprising: in 2017, Stephen and Lynn Briggs opened a farm shop and have since added a café, a huge project that cost not just money but lots of time and energy, too. If he could, Briggs would like to sub-lease the trees to a fruit grower. Briggs is a very experienced and successful grain grower but looking after fruit trees requires a completely different skill set.

Stacking businesses on a farm makes sense, but the tenancy agreement does not allow for a sub-lease. Even with a less than great apple harvest, the trees have contributed to the profitability of the farm this year. In early August, the area around Peterborough was hit by a two-day storm. The grain was already very ripe, and the wind literally thrashed it. Briggs estimates that he lost about 20% of the yield on the unprotected part of the farm. On the silvoarable side he lost only about 10% – and for organic oats that’s a difference of £150 per hectare.

If he could change anything in his silvoarable system, what would it be? He would love to have a more diverse mix of trees and include timber and nut trees. But it takes decades until these species become productive, time a tenant farmer hasn’t got.