D.A. van der Schans

From theory to practice: using canopy reflectance to determine sidedress N rate in potatoes

In potatoes in the Netherlands, more than 40 kg N/ha can be saved on average relative to current practice with a canopy reflectance-based N sidedress system. Farmers report several barriers to adoption of the system. The work described here seeks to remove these barriers through additional experiments. The results show that the sidedress system can be used with various cultivars of ware and starch potatoes, on sandy and clay soils. The results further show that the N-Sensor can be used as is and that the CropCircle can be used after modification of its output. Finally, on-farm comparisons show that the canopy reflectance-based N sidedress system consistently results in yields that are at least as good as those obtained in recommended practice and saves N. It is concluded that the canopy reflectance-based N sidedress system is now ready for practical use in potatoes.