Using the DSSAT Model to Support Decision Making Regarding Fertilizer Microdosing for Maize Production in the Sub-humid Region of Benin
Pierre G. Tovihoudji, P. B. Irénikatché Akponikpè, E. Agbossou, Charles L. Bielders
Frontiers in Environmental Science February 6, 2019 DOI: 10.3389/fenvs.2019.00013 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Modeling study using a 2-year on-station field experiment for calibration and validation, with long-term scenario simulation Peer reviewed |
|---|---|
| Population | Maize crops in a sub-humid tropical environment, tested in a 2-year on-station field experiment (2014 and 2015) |
| Dose | 2 g of NPK15-15-15 fertilizer + 1 g urea per hill (equivalent to 23.8 kg N ha-1, 4.1 kg P ha-1 and 7.8 kg K ha-1) |
| Duration | 2-year on-station experiment (2014 and 2015); long-term scenario analysis |
| Topics | Microdosing |
| Key findings | The DSSAT model, after adjusting the nitrogen stress coefficient, simulated maize grain yields under fertilizer microdosing with a relative RMSE of 10%. Long-term simulations indicated that applying 2 g NPK15-15-15 plus 1 g urea per hill improved minimum guaranteed and long-term average yields without increasing inter-annual variability or economic risk compared with unfertilized plots. Combining microdosing with manure (1-3 t/ha) was slightly riskier but still low-risk, achieving a value-cost ratio of 2 in almost 100% of years, and consistently reduced inter-annual yield variability. |
Abstract
Fertilizer microdosing is being widely promoted across sub-Saharan Africa, yet all recommendations regarding this technology are derived from short-term studies. Such studies are insufficient to properly assess the production risk caused by climatic variability. To address this issue while avoiding costly long-term experiments, a common and well accepted strategy is to combine results from short-term experiments with validated dynamic crop models. However, there have been few documented attempts so far to model fertilizer microdosing under sub-humid tropical conditions. The objective was therefore to evaluate the potential of the DSSAT model for simulating maize response to fertilizer microdosing, and to use the validated model to assess the effects of inter-annual rainfall variability on maize productivity and economic risk. The model was calibrated and validated against data from a 2-year on-station experiment (2014 and 2015) with 2 levels of hill-placed manure and five mineral fertilization options including broadcast and fertilizer microdosing. Model simulations were in good agreement with the observed grain and biomass yields for conventional broadcast fertilization, with relative RMSE and d-values of 12% and 0.96 for grain and 8% and 0.97 for biomass, respectively. For fertilizer microdosing, the N stress coefficient needed to be adjusted to avoid occurrence of large N stresses during simulation. After optimization, the model adequately reproduced grain yields for fertilizer microdosing, with relative RMSE of 10%. Considering the long-term scenario analysis, the use of the validated model showed that the application of 2 g of NPK15-15-15 fertilizer + 1 g urea per hill (equivalent to 23.8 kg N ha-1, 4.1 kg P ha-1 and 7.8 kg K ha-1) improved both the minimum guaranteed yield and the long-term average without increasing inter-annual variability and the economic risk compared to unfertilized plots. Even though combining microdosing with manure (1-3 t ha-1) was economically slightly riskier than microdosing alone, this risk remained low since a value-cost ratio of 2 could be achieved in almost 100% of the years. Furthermore, combined application consistently reduced the inter-annual yield variability.
Comparable studies
Other experimental studies on microdosing, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Microdosing Clinical Study: Pharmacokinetic, Pharmacogenomic (SLCO2B1), and Interaction (Grapefruit Juice) Profiles of Celiprolol Following the Oral Microdose and Therapeutic Dose Healthy volunteers matched for SLCO2B1 genotype | 2011 | Pharmacokinetic study | n = 30 |
| Microdosing psychedelics has no impact on cognitive function in naturalistic settings Participants during their microdosing regimen | 2023 | Observational within-subjects design | n = 17 |
| PK and PK / PD Modeling of Bcl2 Inhibitor S65487 in Patients With AML and Investigation of Nonlinearity With Microdosing Phase I/II cancer patients and healthy volunteers | 2026 | Pharmacokinetic/pharmacodynamic modeling study | |
| Technical pen-based printhead for high-precision microdosing of personalized therapies. | 2026 | Experimental study | |
| Analysis of Serotonin in Caenorhabditis Elegans Subjected to Micro-Dosing with Psilocybin| Iris Publishers Caenorhabditis elegans | 2025 | Experimental study |