Assessment of the 2006 Abuja Fertilizer Declaration with Emphasis on Nitrogen Use Efficiency to Reduce Yield Gaps In Maize Production
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Date
2022
Authors
Winnie, Ntinyari
Giweta, Mekonnen
Gweyi-Onyango, Joseph
Mochoge, Benson
Mutegi, James
Nziguheba, Generose
Masso, Careless
Journal Title
Journal ISSN
Volume Title
Publisher
Frontiers
Abstract
The Abuja Fertilizer Declaration in 2006 recommended the increase of fertilizer use
from the current practice for Sub-Saharan Africa (SSA) to achieve food sufficiency
and improve soil fertility status. However, the current recommended rates of fertilizer
have not been evaluated for specific crops on their potential to reduce the yield gap
and optimize nitrogen use efficiency (NUE). In this study, with nitrogen (N) being a
significant yield-determinant nutrient, four N use scenarios were drawn from existing
recommendations and were evaluated under field conditions for maize crops in two
catchments of the Lake Victoria basin. The scenarios included Business as Usual (BAU,
0 kg N ha−1
), 25% of the Abuja declaration (ADS 12.5 kg N ha−1
), 50% of the Abuja
declaration (ADS 25 kg N ha−1
), and Abuja declaration–Abuja scenario (ADS, 50 kg N
ha−1
). The results revealed that increasing N input levels significantly influenced the
growth and yield of maize crops. The ADS scenario recorded the highest grain yield
increase (167.39%) in Nyando and 103.25% in Rangwe catchments compared to the
BAU scenario. N deficits were observed in all the N use scenarios with a range of −66.6
to −125.7 kg N ha−1
in Nyando and −62.5 to −105.4 kg N ha−1
in Rangwe catchments
with the 50% ADS scenario having the highest deficits. The deficits imply that the added
N input is insufficient to create an N balance for optimal NUE with consequent high risks
of soil N mining. In both catchments, all N use scenarios were within the recommended
agro-physiological N efficiency (APEN) level of between 40 and 60 kg kg−1 N. The partial
N balance obtained at Nyando (1.56–3.11) and Rangwe (1.10–4.64) was higher than the
optimal values, a sign of insufficiency of N inputs and possible risk of soil N depletion
in all the scenarios. Our findings conclude that the proposed N rates in the region
are still very low for food sufficiency and optimized NUE. Therefore, there is a need to
explore other sources of N such as biological N fixation and organic manure and inform
policy- and decision-makers to recommend higher rates beyond the “Abuja declaration”
with the prospect of reaching target yield and optimizing NUE values based on specific
crop recommendations.
Description
Article
Keywords
nitrogen use efficiency, low yield, soil mining, nitrogen deficit, partial N balance, soil fertility, maize
Citation
Winnie, N., Giweta, M., Gweyi-Onyango, J., Mochoge, B., Mutegi, J., Nziguheba, G., & Masso, C. (2022). Assessment of the 2006 Abuja fertilizer declaration with emphasis on nitrogen use efficiency to reduce yield gaps in maize production. Frontiers in Sustainable Food Systems, 5, 559.