Presentation by Johanna Wetterlind, SLU, 2020-01-28

1. Precision farming
for African
Smallholders
Johanna Wetterlind
johanna.wetterlind@slu.se
Departement of Soil and Environment

2. Precision agriculture
"Precision Agriculture is a
management strategy that takes
account of temporal and spatial
variability to improve sustainability of
agricultural production."
Site-specific farming

3. • Natural variation
– Climate
– Soil type
– Topography
– …
• Variation due to management
– Farm type
– Fertilisation strategies
– …
Growing conditions vary
water
organic matter
nutrients
pH
climate
resources

4. • Natural variation
– Weather/climate
– Soil type
– Topology
– …
• Variation due to management
– Farm type
– Fertilisation strategies
– …
Sweden
Kenya
Growing conditions vary
water
organic matter
nutrients
pH
climate
resources

5. Growing conditions vary
20 ha
Plots with 0 nitrogen fertilisation.

6. Matching input to crop demand is the key
Example of nitrogen
fertilisation to winter
wheat.
Delin & Stenberg. 2014. Europ. J.
Agronomy 52, 291–296

7. How to get all the
information needed?
• Too expensive with a lot of
traditional soil and crop analysis.
• Crop and soil sensors
– Remote sensing
– Proximal sensing

8. Precision agriculture for
African smallholders

9. Variations in growing conditions, scale
field – farm - village
• Natural variation
• Variation due to management
Tittonell et al. 2016. Advances in Soil Science
– Fertility decreases with distance from homestead
Fields close to the home receives inputs of carbon and nutrients.
– Reduced fertility in fields close to the homestead compared with more remote fields
Labor and animal manure are limiting
The variation causes variations in fertilisation response.

10. Challenges
• Lack of information
– on site-specific nutrient requirements
– on the PA, often lack of established agronomic service providers
• Lack of resource
– Access to input
– Access to technology and machinery
• Government recommendations on resource use often do not recognize
existing local variation.

11. Opportunities
To recognise and understand the
causes of variations in soil fertility and
crop growing conditions is
fundamental in order to
• increased recourse use efficiency,
and
• possibilities to increase fertilizer
response and yields.

12. IPCC Special report on climate change and land
2019, Chapter 5 Food Security
Low-tech precision agriculture
• Farmers use knowledge and experience in combination with innovative
approaches.
• Has the potential to increase the economic return per unit land area
while also creating new employment opportunities

13. New ways of getting information