05 March 2026
Growing beans and sunflowers in its crop of forage maize has seen a Pembrokeshire dairy farm raise the crude protein (CP) level in that silage to nearly 14%.
Volatile feed prices prompted the Evans family to explore alternatives for supplying protein in the rations for their growing heifers and 200-cow pedigree Holstein herd at Berryhill Farm, Newport.
With 150 – 200 acres grown every year on the 380 acres farmed, maize is integral to the stocks diet.
Increasing the protein potential of that acreage offered an opportunity to reduce purchased feed costs by capitalising on homegrown forage.
In some countries, notably Germany, growing legumes with maize is relatively commonplace and successful and used by farmers to produce more protein on-farm.
Teaming up with Farming Connect to run a Focus Farm study on this system, the Evans’ are now in their fifth year of growing a proportion of their maize with legumes and sunflowers.
Weeds have proved their biggest challenge to intercropping but when they get it right, they have been rewarded with a forage of exceptional nutritional quality.
In 2025 it analysed at 23.7% dry matter (DM), 13.73% CP, an ME of 10.6MJ/kg DM, a digestibility (D) value of 67, and a neutral detergent fibre (NDF) digestibility of 72%; in comparison, CP in the farm’s maize-only silage was 8%.
That protein is high quality too since it features lysine and methionine which aren’t usually present in forage and more closely associated with soya; they are prized for their ability to improve milk yield and quality, and support dairy cow reproduction.
At drilling, the maize and legume seeds are combined in a Belle mixer and planted at the same time since the seeds are similar in size, a system the Evanses switched to after trialling a different process in their first growing year, says Jonathan Evans, the third generation at Berryhill Farm.
In that initial year the maize was planted first, and the beans when the maize plants had grown to around six inches in height but, as Jonathan recalls: “By doing it this way we had no control over weeds and lost about 20 acres.’’
Different seed ratios have been trialled too, including 80:20 maize and beans and 50:50, but he now aims for a 60:40 ratio.
By planting the seed together, an Einbock can be used to remove weeds three or four days after drilling, but there can also be issues with this drilling approach too as it doesn’t guarantee an even distribution of each seed variety.
As the bean grows by attaching itself to a maize plant, when there is a high concentration of beans in one patch, they will seek maize plants in neighbouring rows, snapping maize stems as they do so.
The pattern for drilling is different to a maize-only crop too, Jonathan explains, and it is crucial to get it right otherwise weeding becomes an even greater challenge.
“We only go around the headlands twice then try to keep everything in straight lines,’’ he says.
Drilling is done in-house as harvesting maize and grass are the only jobs outsourced.
Two climbing bean varieties, Rancho and Solgado are grown; Rancho is quicker to mature and well matched to an earlier maize variety while Solgado has a bigger pod but matures three to four weeks later than Rancho.
“We have been matching the beans to maize varieties but this year we will try to match the maize to the right beans,’’ says Jonathan.
Different forms of mechanical inter row weeding have been trialled including with an Amazone Venterra and rotary weeding using a Rotocare.
Berryhill intercrops around a quarter of total maize acreage but in some years more – last year 80 acres were grown with around 20 acres of these incorporating sunflowers. “That produces enough to feed high end stock through the winter to the spring,’’ says Jonathan.
The stock responds well to sunflowers, he adds.
“In the first year that we added sunflowers to the mix, the youngstock grew really well on it, their coats had a nice shine and there was no coughing so for the last two years we have grown all three species.’’
Growing heifers in the ‘Holm’ herd are achieving target weights on a ration of 20kg maize, bean and sunflower silage, 2kg hybrid rye and 1kg blend.
By including the maize, bean and sunflower mix, it has been possible to reduce blend in that ration by 2kg.
The milking cow ration is 27kg maize silage, 17kg grass silage and 8.5kg blend
Five years after introducing the system and Jonathan admits he is still learning how to get it right. “I have gained a lot of knowledge, every year throws up different challenges, but I know we will get there through trial and error.
“Intercropping is definitely something I will continue with because it offers so many benefits.’’
These include soil health as he has seen a marked improvement in soil biology and structure in his maize fields.
“The land drains better, you can get on it earlier in the season, and worm activity is massively up,’’ says Jonathan.
As legumes are nitrogen fixing, synthetic fertiliser is no longer used prior to first cut in fields where maize and beans were grown the previous year.
“Once the maize comes off, we run the discs through the soil and then plant a Westerwold or a ryegrass, apply slurry, and get 7-10t/acre of grass from this before we turn the field back over to maize and beans,’’ Jonathan explains.
Weed challenges would be fewer if ploughing was used, he reckons, but he wants to stick to the current min-till policy.
Supported by milk buyer, Leprino, the farm has been working to reduce its carbon footprint and is making big progress, cutting it by 35% in the last four years.
Soil analysis from maize fields demonstrate how min-till has contributed - one field for example has 4.8 units of carbon per hectare compared to 1.7 in 2021.
Maize is fundamental to the system at Berryhill, more so now than ever as the farm is switching to robot milking this spring. Three robot milkers are currently being installed.
“Anything I can do to grow more protein is going to help with cost of production and if I can improve the soil at the same time and reduce carbon emissions it will all be moving in the direction that we want to follow,’’ says Jonathan.
“Intercropping is worth doing but it is quite challenging to get it right, if you get a dry summer the beans will outgrow the maize and if the spring is wet and we can’t get on the land with a weeder the weeds will take over and beans and weeds will outgrow the maize.’’
Growing legumes as a dedicated crop is an option but Jonathan says with maize such an important part of his system he doesn’t want to reduce maize acreage.
“Maize is such a consistent feed compared to grass silage which can vary considerably from one field to the next.
“When we switch from one grass silage clamp to another, we don’t see an impact on milk production because the ration has a much higher quantity of maize silage.’’