Journal Papers
A curated collection of peer-reviewed research papers on soil fertility, nutrient cycling, agricultural productivity, and food systems transformation, with a focus on Africa and other tropical regions.
Calibration of the QUEFTS Model (1993)
Smaling, E.M.A. & Janssen B.H.
Calibration of QUEFTS, a model predicting nutrient uptake and yields from chemical soil fertility indices.
Geoderma, Vol. 59, pp. 21–44.
​
Brief description
This paper calibrates the QUEFTS (Quantitative Evaluation of the Fertility of Tropical Soils) model using maize fertilizer trial data from Kenya, improving predictions of nitrogen, phosphorus, and potassium uptake and associated yields based on soil chemical fertility indicators.
Links
• Publisher (ScienceDirect – abstract & purchase/access options):
https://www.sciencedirect.com/science/article/pii/001670619390060X
​
• DOI (permanent scholarly link):
https://doi.org/10.1016/0016-7061(93)90060-X
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
A Decision-Support Model for Monitoring Nutrient Balances (NUTMON)
Smaling, E.M.A. & Fresco L.O. (1993)
​
A decision-support model for monitoring nutrient balances under agricultural land use (NUTMON).
Geoderma, Vol. 60, pp. 235–256.
​
Brief description
​
This article presents NUTMON, a decision-support model that extends a quantitative nutrient balance framework (NUTBAL) to help monitor the balance between nutrient inputs and outputs (N, P, K) under agricultural land use. NUTMON allows evaluation of how changing land use, soil management, and policy interventions impact nutrient balances at farm, regional, and supra-national scales, with case elaborations from Kisii District, Kenya.
​
Links
​
• Publisher (ScienceDirect – abstract & access options):
https://www.sciencedirect.com/science/article/pii/001670619390029K
• DOI (permanent scholarly link):
https://doi.org/10.1016/0016-7061(93)90029-K
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
The Itinerary of Soil Nutrients in Africa: Destination Anywhere? (2000)
Smaling, E.M.A. & Toulmin C. (2000)
​
The itinerary of soil nutrients in Africa: destination anywhere?
Outlook on Agriculture, Vol. 29, pp. 193–200.
Brief description
​
Brief description
​
This article examines the movements and distribution of soil nutrients across Africa’s agricultural landscapes, highlighting patterns of nutrient depletion and the challenges of maintaining soil fertility under contemporary land use. It discusses how nutrient flows intersect with farming practices, market forces, and policy environments across different regions of the continent.
​
Links
​
• Publisher (SAGE – abstract & access options):
https://journals.sagepub.com/doi/10.5367/000000000101293239
• DOI (permanent scholarly link):
https://doi.org/10.5367/000000000101293239
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
Analyzing Successes in Agriculture and Land Management in Sub-Saharan Africa (2008)
Reij, C.P. & Smaling, E.M.A. (2008)
​
Analyzing successes in agriculture and land management in Sub-Saharan Africa: Is macro-level gloom obscuring positive micro-level change?
Land Use Policy, Vol. 25, pp. 410–420.
​
Brief description
​
This paper reviews evidence of positive agricultural and land management changes in Sub-Saharan Africa over several decades, contrasting commonly cited regional challenges with documented case successes at local scales. It highlights specific instances where crop, livestock, and environmental management improvements have occurred, and discusses how such micro-level changes can be masked by macro-level narratives of agricultural decline.
​
Links
​
• Publisher (Elsevier – abstract & access options):
https://www.sciencedirect.com/science/article/abs/pii/S0264837707000804
• DOI (permanent scholarly link):
https://doi.org/10.1016/j.landusepol.2007.10.001
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
From Forest to Waste: Assessment of the Brazilian Soybean Chain (2008)
Smaling, E.M.A., Roscoe, R., Lesschen, J.P., Bouwman, A.F., & Comunello, E. (2008)
​
From forest to waste: Assessment of the Brazilian soybean chain, using nitrogen as a marker.
Agriculture, Ecosystems & Environment, Vol. 128, pp. 185–197.
Brief description
​
Brief description
​
This paper quantifies nitrogen (N) stocks and flows across the Brazilian soybean production chain — from forest conversion to cultivation, processing, transport, consumption, and waste — using N as a marker of nutrient movement and loss at each stage. The study highlights large transfers of N associated with land conversion, harvest removal, processing into soy meal, and export, showing how soybean expansion affects nutrient balances and offers opportunities for recycling.
​
Links
​
• Publisher (ScienceDirect – abstract & access options):
https://www.sciencedirect.com/science/article/pii/S0167880908001795
• DOI (permanent scholarly link):https://doi.org/10.1016/j.agee.2008.06.005
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
Integrated Soil Fertility Management (2010)
Vanlauwe, B., Bationo, A., Chianu, J., Giller, K.E., Merckx, R., Mokwunye, U., Ohiokpehai, O., Pypers, P., Tabo, R., Shepherd, K.D., Smaling, E.M.A., Woomer, P.L., & Sanginga, N. (2010)
​
Integrated soil fertility management. Operation definition and consequences for implementation and dissemination.
Outlook on Agriculture, Vol. 39, pp. 17–24.
​
Brief description
​
This article defines Integrated Soil Fertility Management (ISFM) as an approach that combines the use of fertilizers, organic inputs, and improved germplasm with appropriate agronomic practices to maximize nutrient use efficiency and crop productivity. It reviews how ISFM principles can be implemented and disseminated at scale in smallholder systems, highlighting the roles of institutional support, knowledge sharing, and locally adapted practices across Sub-Saharan Africa.
​
Links
​
• Publisher (SAGE Journals – abstract & access options):
https://journals.sagepub.com/doi/10.5367/000000010792677212
• DOI (permanent scholarly link):
https://doi.org/10.5367/000000010792677212
​
(Note: Full text is behind an Elsevier paywall; access typically requires institutional subscription or individual purchase.)
Towards Food Systems Transformation — Five Paradigm Shifts (2021)
Ruben, R., Cavatassi, R., Lipper,
L., Smaling E. & Winters P. (2021)​
​
Towards food systems transformation — five paradigm shifts for healthy, inclusive and sustainable food systems.
Food Security, Vol. 13, pp. 1423–1430. https://doi.org/10.1007/s12571-021-01221-4
​
Brief description
​
This open-access article identifies five fundamental paradigm shifts needed to transform global food systems so they simultaneously deliver healthy diets, inclusive livelihoods, environmental sustainability, and resilience. It outlines how food system policy, governance, and connectivity between production and consumption goals must evolve to overcome trade-offs and build synergies across outcomes.
Links
​
• Publisher (Springer – full open access):
https://link.springer.com/article/10.1007/s12571-021-01221-4
• DOI (permanent scholarly link):
https://doi.org/10.1007/s12571-021-01221-4
​
(This article is open access under a Creative Commons Attribution 4.0 license, meaning the full text can be shared and used with proper attribution.)
Cereal Yields in Ethiopia Relate to Soil Properties and N and P Fertilizers (2023)
Elias E., Okoth, P.F., Stoorvogel, J.J., Berecha G., Mellisse B.T., Mekuriaw A., Gebresamuel G., Selassie Y.G., Biratu G.K. & Smaling, E.M.A. (2023)​
​
Cereal yields in Ethiopia relate to soil properties and N and P fertilizers.
Nutrient Cycling in Agro-Ecosystems, Vol. 126, pp. 279–292. DOI: https://doi.org/10.1007/s10705-023-10291-z
​
Brief description
​
This open-access article presents findings from a large field experiment (33 trials) in the Ethiopian Highlands showing how cereal (maize, teff, and wheat) yields are influenced by soil properties (soil type and organic carbon) and different nitrogen and phosphorus fertilizer levels. The results highlight strong correlations between soil characteristics and crop responses to fertilizer, underscoring the importance of soil-specific nutrient management strategies.
​
Links
​
• Publisher (Springer – full text open access):
https://link.springer.com/article/10.1007/s10705-023-10291-z
• DOI (permanent scholarly link):
https://doi.org/10.1007/s10705-023-10291-z
​
(This article is open access under a Creative Commons Attribution 4.0 License, meaning the full text can be shared and used with proper attribution.)
Complete Research Output
WUR Publication List: https://research.wur.nl/en/persons/e-smaling/publications/
ResearchGate: https://www.researchgate.net/profile/Eric-Smaling