1. Field Experiments 2014 FIGARO: Partner 2 Department of AGROECOLOGY Aarhus University

2. Irrigation in Denmark 400.000 hectares – 20% of agr.area
Mainly sandy soils western part of DK
Mainly travelling rainguns
Simple Decision Support online System for farmers based on our field experimental data (water balance and yield)

3. 3
Clay
Silt
Fine sand
Coarse sand

4. Expectations to FIGARO:
Drip in Potato:
Platform will be developed that makes drip economical feasible.
Includes fertigation which result in lower N and water use and higher quality and yield of potatoes.

6. 4 replicates of each treatment – randomized design Large plots
Experiment 1
Irrigation system
Irrigation
Criteria
frequency
Fertilization
Dressing time
Gun Irrigation
Figaro
Daisy
25mm
Whenever water deficit equals 25mm
120 kg N ha-1
30 kg P ha−1
180 kg K ha−1
Planting
Drip Fertigation
3. Daisy
90% θf –SWCt
Every two days
30% of calculated N demand
70% of calculated N demand
When critical N level is reached
based on Daisy
and applied in 20 kg N ha-1 portions
4 replicates of each treatment – randomized design Large plots

7. Experiment 1

8. Based on TDR-measurements: Replenish previous two days water deficit with upper threshold 0.9*FC
Based on TDR-measurements: 80 % of I1 at the tuber initiation stage and 60% of I1 from tuber bulking
Experiment 2:
Two factors are implemented in this experiment, irrigation amount and nitrogen regime:
Irrigation guided with Aquacrop model
Irrigation guided with Daisy model
42 kg N at planting. Afterwards Daisy to guide N
42 kg N at planting. Afterwards Daisy to guide N

9. TDR
Measuring Soil water content

10. Experiment 2
2013

11. Experiment 2
N-uptake

12. Experiment 2

13. Experiment 2

14. Experiment 2

15. MobilLas
Measuring N-requirement

16. Measurements WP3 – WP4 – WP8 –WP9
Sap flow
Gas ex-change
Soil water: aut.TDR/tensiometers
Plant water potential
Light absorption

17. Influence of irrigation on potato quality
Irrigation at low soil-water deficit (18 mm JB1/24 mm JB2) caused:
Tuber initiation stage:
More tubers
More middle-sized tubers
Large reduction of scab on JB1
Better skin quality
Better cooking quality
Tuber bulking stage:
Less dark-coloration during cooking
Slightly inferior skin quality
Inferior chips quality
Higher yield
Jørgensen (1984)