Regional estimates of nitrogen budgets for agricultural systems in the East African Community over the last five decades

Barthelemy Harerimana; Minghua Zhou; Bo Zhu; Peng Xu

doi:10.1007/s13593-023-00881-0

Regional estimates of nitrogen budgets for agricultural systems in the East African Community over the last five decades

Agron Sustain Dev. 2023;43(2):27. doi: 10.1007/s13593-023-00881-0. Epub 2023 Mar 8.

Authors

Barthelemy Harerimana^{1

2}, Minghua Zhou¹, Bo Zhu¹, Peng Xu¹

Affiliations

¹ Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, No.189, QunXianNan Street, Tianfu New Area, Chengdu, 610041 China.
² University of Chinese Academy of Sciences, Beijing, 100049 China.

Abstract

The great challenge of reducing soil nutrient depletion and assuring agricultural system productivity in low-income countries caused by limited synthetic fertilizer use necessitates local and cost-effective nutrient sources. We estimated the changes of the nitrogen budget of agricultural systems in the East African Community from 1961 to 2018 to address the challenges of insufficient nitrogen inputs and serious soil nitrogen depletion in agricultural systems of the East African Community region. Results showed that total nitrogen input increased from 12.5 kg N ha^-1yr^-1 in the 1960s to 21.8 kg N ha^-1yr^-1 in the 2000s and 27 kg N ha^-1yr^-1 in the 2010s. Total nitrogen crop uptake increased from 12.8 kg N ha^-1yr^-1 in the 1960s to 18.2 kg N ha^-1yr^-1 in the 2000s and 21.8 kg N ha^-1yr^-1 in the 2010s. Soil nitrogen stock increased from -2.0 kg N ha^-1yr^-1 in the 1960s to -0.5 kg N ha^-1yr^-1 in the 2000s and 0.3 kg N ha^-1yr^-1 in the 2010s. Our results allow us to substantiate for the first time that soil nitrogen depletion decreases with increasing input of nitrogen in agricultural systems of the East African Community region. This suggests that increases in nitrogen inputs through biological nitrogen fixation and animal manure are the critical nitrogen management practices to curb soil nitrogen depletion and sustain agricultural production systems in the East African Community region in order to meet food demand for a growing population.

Supplementary information: The online version contains supplementary material available at 10.1007/s13593-023-00881-0.

Keywords: Agricultural system; Animal nitrogen manure; Biological nitrogen fixation; East African Community; Nitrogen loss; Nitrogen management; Nitrogen use efficiency; Soil nitrogen depletion; Soil nitrogen stock.

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