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Background
Information about the global
structure of agriculture and nutrient production and its diversity is
essential to improve present understanding
of national food production patterns, agricultural livelihoods, and food
chains, and their linkages to land use
and their associated ecosystems services. Here we provide a plausible breakdown
of global agricultural and
nutrient production by farm size,
and also study
the associations between
farm size, agricultural
diversity, and nutrient production. This analysis is crucial to design
interventions that might be appropriately targeted to promote healthy diets and ecosystems in
the face of population growth, urbanisation, and climate change.
Methods
We
used existing spatially-explicit global
datasets to estimate
the production levels
of 41 major
crops, seven livestock, and 14
aquaculture and fish products. From overall production estimates, we estimated
the production of vitamin A, vitamin
B₁₂, folate, iron, zinc, calcium, calories, and protein. We also estimated the
relative contribution of farms of
different sizes to the production of different agricultural commodities and
associated nutrients, as well as
how the diversity
of food production
based on the
number of different
products grown per
geographic pixel and
distribution of products within this pixel (Shannon diversity index [ H
]) changes with different farm sizes.
Findings
Globally, small
and medium farms
(≤50 ha) produce
51–77% of nearly
all commodities and
nutrients examined here.
However, important regional differences exist. Large farms (>50 ha) dominate
production in North America, South
America, and Australia and New Zealand. In these regions, large farms
contribute between 75% and 100% of all
cereal, livestock, and fruit production, and the pattern is similar for other
commodity groups. By contrast,
small farms (≤20
ha) produce more
than 75% of
most food commodities
in Sub-Saharan Africa,
Southeast Asia, South Asia, and China. In Europe, West Asia and
North Africa, and Central
America, medium-size farms (20–50 ha)
also contribute substantially to the production of most food commodities.
Very small farms (≤2 ha) are important and
have local significance in
Sub-Saharan Africa, Southeast Asia,
and South Asia, where they contribute to
about 30% of most food commodities. The
majority of vegetables (81%), roots and tubers (72%), pulses (67%), fruits
(66%), fish and livestock products
(60%), and cereals (56%) are produced in diverse landscapes ( H >1·5).
Similarly, the majority of global
micronutrients (53–81%) and
protein (57%) are
also produced in
more diverse agricultural
landscapes ( H >1·5). By
contrast, the majority
of sugar (73%)
and oil crops
(57%) are produced
in less diverse
ones ( H ≤ 1·5), which
also account for
the majority of
global calorie production
(56%). The diversity
of agricultural and
nutrient production diminishes
as farm size increases. However, areas of the world with higher agricultural
diversity produce more nutrients,
irrespective of farm size.
Interpretation
Our results show that farm size and
diversity of agricultural production vary substantially across regions and are
key structural determinants
of food and
nutrient production that
need to be
considered in plans
to meet social,
economic, and environmental targets. At the global level, both small and
large farms have key roles in food and nutrition security. Efforts to maintain production
diversity as farm sizes increase seem to be necessary to maintain the
production of diverse nutrients and
viable, multifunctional, sustainable landscapes.
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