COMPARISON OF SPLIT NITROGEN APPLICATION STRATEGIES IN LEEK (ALLIUM PORRUM) TO REDUCE N FERTILIZATION ON SANDY SOILS IN THE NETHERLANDS

High nitrogen (N) fertilization to maximize production of leek (Allium porrum L.) combined with low N recovery can lead to considerable nitrogen pollution of the environment.
A field trial was conducted in 2002 and 2003 on a sandy soil in the Netherlands.
To synchronize N supply and N demand, two strategies of sequential split nitrogen application (SNA) were compared: 1) SNA-soil: in which the split N applications are the difference between standardized crop demand and the available amount of mineral N in the soil for each period; 2) Crop Scan method: in which the split N applications are derived from comparing the actual crop nitrogen status to the desired nitrogen status, using crop reflectance measurements and a crop growth model.
Total fertilizer application according to Crop Scan method in 2002 saved 65 kg N ha^-1 compared to recommendation of SNA-soil, maintaining maximal production.
In 2003 the total N application of SNA-soil and Crop Scan were respectively 95 and 113 kg N ha^-1, whereas a N application of 45 kg N ha^-1 was sufficient.
The Crop Scan method overestimated the N application needed in 2003 because it did not account for the high mineral N content in the soil.
SNA-soil overestimated the N application needed in autumn in both years.
Combination of Crop Scan measurements, to assess plant N need, and soil N analysis may cover the flaws, which each method separately showed.

International Symposium Towards Ecologically Sound Fertilisation Strategies for Field Vegetable Production

W.C.A. van Geel, E.J.J. Meurs, S. Radersma, C. Grashoff

Allium porrum, nitrogen uptake, nitrogen demand, nitrogen need, Crop Scan

https://doi.org/10.17660/ActaHortic.2006.700.42