Most of 1,500 dairy farmers who took part in an experiment to replace their cows’ ryegrass with a mixture of CO2-absorbing herbs and grasses to combat climate change are happy with the results.

The three-year experiment, initiated by environmental organisation Urgenda and the farmers’ association LTO, has shown that the farmers who used the mixture had hardly any need for artificial fertiliser, reducing CO2 output by three million kilos a year. Some 4,700 hectares of meadow have now been sown with the mixture.

Some 77% of the dairy farmers reported an increase in insect numbers while 20% said meadow birds had also made a comeback. Over half of the farmers (56%) said their land had been better able to withstand dry conditions. Nearly all said milk yield remained the same, or had even improved.

“The mixture of herbs, clover and grasses make for a much more varied meal for the cows and I no longer have to use artificial fertiliser,” Brabant dairy farmer Kees Pijs told the AD.

“That makes it cheaper and is better for the environment. The roots of this mixture go deeper and that makes the water table more stable in this dry sandy soil, and that in turn means I can delay irrigation.”

Most of the dairy farmers will continue to use the mixture but some 4% said they will return to ryegrass.

“It’s not a complete success story,” dairy farmer Rudie Freriks from Overijssel told the paper. “It’s not as easy to manage as ryegrass. The cows like it but you can see that the herbs disappear after a couple of years. Herb seed is very expensive. But the yield is fine, and that the cows and the soil have improved.”

Urgenda and LTO said they are aware the seed is more expensive and have called on the government to offer financial support to farmers who want to make the change so that all 13,000 dairy farmers in the Netherlands will follow suit.

Arable farmers have also shown an interest, the organisations said, with 200 sowing five hectares each of the CO2-busting mixture this summer.