Controlled drainage boosts water economy in an environmentally friendly way

The owners of Härmä farm in Tyrnävä strive to constantly develop their operations by increasing the yield and improving the quality of their finished product. Brothers Simo and Lauri Rahko recognise that boosting operations also increases profitability.

“Maveplan has helped us to improve our water economy. Their experts know what they are doing and we have been very happy with their service. I look forward to continuing our cooperation with Maveplan.”Lauri Rahko
Härmä Farm

Including rented fields, Härmä Farm has approximately 260 hectares of arable land, of which about 90 hectares is used each year in the production of seed potatoes. The potatoes are stored and inspected for sale in the farm’s own warehouses and packaging facility. All seed potatoes are sold and marketed through the seed potato company HZPC Kantaperuna Oy, while grain crops are sold to dealers or directly to farms to be used as animal fodder.

Water economy has a significant impact on the success of potato farming. Uncontrolled changes in soil moisture levels can cause the potato tubers to grow at different rates or into different shapes, develop growth cracks or expose the tubers to common scab. Excess moisture can also deplete soil oxygen levels, which may suffocate the field and ruin the tubers. Even a 10% change in the moisture level is enough to cause significant problems.

For the field to yield crops, the soil permeability must be ensured through an appropriate field drainage system, which is why the Rahko brothers contacted Maveplan.

Cooperation between Maveplan and Härmä Farm started during the previous generation. Maveplan’s experience and expertise, along with its proven services, convinced Simo and Lauri Rahko that Maveplan would also be the best possible partner for this project.

When the field drainage plan was being drafted, the brothers brought up better utilisation of the existing controlled drainage system, which can significantly help to reduce the leaching of nitrogen into waterways. With field drains, farmers can boost their crop yield while taking into account the needs of water protection and promoting sustainable development in the best possible way.

In accordance with the plan, a decision was made to make the network of field drains denser and to replace some of the old field drains. Controlled irrigation is used to further boost the efficiency of the nutrients used by the crops. By recycling runoff water, some of the nutrients in the runoff can be directed back to the field, which reduces the leaching of valuable nutrients into waterways and away from the crops.

Lauri Rahko is pleased with how Maveplan planned and executed the project. The water economy of the fields of Härmä Farm has improved significantly, so it’s fair to say that the goals set for the project have been met.

Improving competitiveness will also be key to the success of Härmä Farm – and Finnish agriculture in general – in the coming years. At Härmä Farm, the work to improve quality and profitability will continue, and Lauri Rahko believes that working with Maveplan will also help the farm succeed in the future.


  1. Improved water economy of fields
  2. Drainage projects planned and executed by experts
  3. Improved nutrient efficiency
  4. Addressing the needs of water protection

Agricultural group Rahko Simo and Lauri / Härmä Farm

  • Crop farming, seed potato production, cereal production
  • A 260-hectare potato and cereal farm in Tyrnävä, owned by the Rahko family since the 19th century
  • Average seed potato yield of approx. 30 tonnes per hectare
  • Seed potatoes are sold and marketed through the seed potato company HZPC Kantaperuna Oy

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