Nitrogen Budgets and Nitrogen Use Efficiency as Agricultural Performance Indicators in Lake Victoria Basin

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Date
2022-10-21
Authors
Ntinyari, Winnie
Onyango, Joseph Gweyi
Giweta, Mekonnen
Mutegi, James
Mochoge, Benson
Nziguheba, Generose
Journal Title
Journal ISSN
Volume Title
Publisher
iop publisher
Abstract
Too little nitrogen (N) is a threat to crop productivity and soil fertility in sub- Saharan Africa (SSA). Nitrogen budgets (NB) and nitrogen use e ciency (NUE) are critical tools for assessing N dynamics in agriculture and have received little or no attention in the region. Data were collected from smallholder farmers clustered into two categories, farmers applying and farmers not applying N fertilizers. NB were calculated using the Coupled Human and Natural Systems (CHANS) model approach for field and farm spatial scales. The results showed spatial variabilities in NB and NUE at the field level (maize and rice) across all the catchments. At the field level, N balances were negative for the two crops in all the catchments. Similarly, at the farm gate, a deficit of −78.37 kg N ha−1 was observed, an indicator of soil Nmining. NUE values at the field scale varied across the catchments for both crops, with values for maize grown without N ranging from25.76 to 140.18%. Even with the application ofmineral N at higher levels in rice fields compared to maize fields, NUE values ranged between 81.92 and 224.6%. Our study revealed that the Lake Victoria region su􀀀ers from ine cientNcycling due to depleted soilNpools and lowsynchrony betweenN input and N removal. Therefore, a challenge lies in exploiting more sustainable N sources for farmers in the region for sustainable farming systems. The NB and NUE provide critical information to agriculture stakeholders to develop environmental, agronomic, and economically viable Nmanagement solutions.
Description
article
Keywords
cropping system, mineral fertilizer, N losses, N management, soil depletion
Citation
Ntinyari W, Gweyi-Onyango J, Giweta M, Mutegi J, Mochoge B, Nziguheba G and Masso C (2022) Nitrogen budgets and nitrogen use e ciency as agricultural performance indicators in Lake Victoria basin. Front. Sustain. Food Syst. 6:1023579. doi: 10.3389/fsufs.2022.1023579