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The self-reinforcing feedback between low soil fertility and chronic poverty

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Abstract

Most of the world's extreme poor, surviving on US$1.25 or less per day, live in rural areas and farm for a living. Many suffer chronic poverty that lasts for years or generations, rather than the transitory poverty that dominates developed, urban economies. Such chronic, structural poverty arises when an individual's productive assets — such as their ability to work or their soils — and the technologies and markets that transform their assets into food and income are insufficient to attain satisfactory living standards. Research reveals strong links between economic status and soil quality, and these can be self-reinforcing. For example, poor soil constrains agricultural production and household capital, and low household capital constrains investments in improving soils. Price, availability and access to credit can limit farmers' applications of nutrients, which are often the primary constraint on agricultural productivity. Soil micronutrient deficiencies can lead to dietary mineral deficiencies and negative health outcomes that further constrain productivity and household asset accumulation. Soils may also be important for smallholder resilience to stressors and shocks. For example, high-quality soil can reduce vulnerability to drought, and insurance against risk may promote investment in soils. Interventions such as fertilizer subsidies, micronutrient-fortified fertilizer and improved access to information, insurance and credit may all help break the soil–poverty cycle.

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Figure 1: Soil nutrient flows are positively correlated with per-capita income in sub-Saharan Africa, for both 1983 and 2002–2004.

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Acknowledgements

Julia Berazneva, Ken Giller, Teevrat Garg, Chris Golden, Stein Holden, Johannes Lehmann, Linden McBride, Pedro Sanchez, Ross Welch, Meghan Sheahan, Rachel Hestrin and Bernard Vanlauwe each offered helpful comments on an earlier draft of this paper.

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Both authors conceived of and designed the research, and drafted, reviewed, edited and revised the manuscript. L.E.M.B. performed data analysis.

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Correspondence to Christopher B. Barrett.

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Barrett, C., Bevis, L. The self-reinforcing feedback between low soil fertility and chronic poverty. Nature Geosci 8, 907–912 (2015). https://doi.org/10.1038/ngeo2591

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