1. Drip irrigation in Finland Merja Myllys 1 and Osmo Purhonen 2* 1 MTT Agrifood Research Finland, Plant Production Research, FI-31600 Jokioinen, Finland 2 Myllykyläntie 28, FI-20960 Turku, Finland * corresponding and presenting author, purhonenosmo@gmail.com

2. Contents Need for irrigation Irrigation methods Drip irrigation; latest results 1.potato crop production 2.horticultural crop production Future prospects

3. Picture: Finnish Field Drainage Centre Precipitation and evaporation in Finland

4. Need for irrigation Boreal climatic zone Water deficiency from May to July ≈125 mm Need for irrigation depends on storage capacity of soil Drainage is more important than irrigation Irrigation is also used to prevent frost damages (20-40 mm/night)

5. Irrigation methods Irrigation was introduced late: in 1960’ Sprinkler and boom irrigation are prevailing methods 9% of farms have irrigation equipment 80 000 hectares out of 2.4 milj. hectares can be irrigated Irrigation water from natural watercourses 2% of total run-off is utilized for municipal and industrial purposes, minor part for irrigation

6. Irrigation methods

7. Drip irrigation Novel method on field

8. 1) Drip irrigation in potato crop production On-farm field experiment; one main farm (all treatments) + four others (some treatments in each) Treatments: drip irrigation, sprinkler, boom, subsurface irrigation, no irrigation Measurments/observations: water and nutrient status of the soil, yield and yield quality of the potato crop

9. Drip irrigation in potato crop production +All methods increased yield +Drip irrigation increased proportion of marketable yield (tuber size 35-55 mm)

10. Drip irrigation in potato crop production +Possibility to add liquid fertilizes in the irrigation water increased the important calcium content in the tubers

11. Drip irrigation in potato crop production +Drip irrigation diminished leaching of nutrients during growing season (the red bar indicates how much nutrients are left after harvest)

12. 2) Drip irrigation in horticultural crop production Joint series of field experiments Crops were pickling cucumber, strawberry, black currant and raspberry Production practises, work demand, and economy were studied Guidelines for farmers were made

13. Drip irrigation in horticultural crop production +Crop benefited from drip irrigation which was started when tensiometres indicated suction of -150 to -300 hPa. +Especially berry crops benefited from added fertilizers in the irrigation water

14. Drip irrigation in horticultural crop production -Installation of drip irrigation system requires a lot of work -Production costs per farm increase +Production costs per kg of yield decreased if the amount of yield exceeded 8 – 9 000 kg/ha for strawberry 6 - 9 000 kg/ha for black currant 55 000 kg/ha for pickling cucumber

15. Conclusions As water reservoirs are plenty in Finland, lack of irrigation water is not the main reason to choose drip irrigation instead of another method. Reasons are +the possibility for fertilization during the growing season +minimized leaching of nutrients +efficient use of water and nutrients +ease of use once installed

16. Conclusions Disadvantages of drip irrigation are -Laborious installing -The fact that drip irrigation cannot be used for preventing frost damages

17. Future prospects Drip irrigation will be more commonly used in high value perennial crop production Due to high installation cost drip irrigation will not be widely used for annual crop production Need for irrigation will increase due to climate change

18. Thank you!