NLOS-OG: a management tool for nitrogen fertilization in organic greenhouses
Because of the complexity of the nitrogen (N) cycle and the diversity of its molecule forms in the soil, N fertilization management is based on complex conceptual or computational models.
For organic farming, N is provided via organic amendments and biological fixation.
However, lack of precise tools that predict the N mineralization rate of N sources lead some producers to over-fertilize, resulting in the buildup of salinity, N leaching and possible loss of profits.
Consequently, better knowledge of N availability following organic fertilization, to improve synchronization of N supply with crop N demand, is crucial to advance sustainable organic horticulture.
Our objective was to determine the mineralization rate of commonly-used organic N fertilizers by adapting a broad N management tool to guide N fertilization in organic greenhouse.
We conducted a one-year incubation experiment to determine whether N mineralization of a mix of organic fertilizers can be predicted from mineralization rates determined individually for each fertilizer, and if the prediction is accurate across N application rates.
We adapted the existing N management model NLOS (www.nlos.ca) to greenhouse organic horticulture and employed data from the incubation experiment to model organic fertilizers with low C/N ratio.
We also report a N budget from an organic tomato greenhouse crop as validation of the model.
In its current state, our model slightly underestimates mineral N in organic greenhouses, while allowing good and easily obtained estimates of N availability and losses.
A web-based interface for the model (NLOS-OG) will soon be freely available.
This new tool will help growers manage N by improving the synchronization of supply of organic fertilization with crop demand.
The NLOS-OG tool is available at https://exchange.iseesystems.com/public/pierrepauldion/nlos-og/.
Dion, P.P., Thériault, M., Hunt, D., Bittman, S., Pepin, S. and Dorais, M. (2020). NLOS-OG: a management tool for nitrogen fertilization in organic greenhouses. Acta Hortic. 1296, 1093-1098
DOI: 10.17660/ActaHortic.2020.1296.138
https://doi.org/10.17660/ActaHortic.2020.1296.138
DOI: 10.17660/ActaHortic.2020.1296.138
https://doi.org/10.17660/ActaHortic.2020.1296.138
amendment, leaching, mineralization, STELLA model, nitrogen cycle, organic fertilizer, uptake
English
1296_138
1093-1098