Opportunities for crowdsourcing approaches and

satellite images for yield gap analysis

Eskender Andualem Beza

May 12, 2015

GRS – Integration

Outline

Introduction

●Yield gap

●Definitions

What factors to collect

●Meta-analysis ●Result: Meta-analysis

How to collect factors ● Innovative data collection approaches

● Crowdsourcing

● Remote sensing

Introduction: Yield gap

(Van Ittersum and Rabbinge, 1997; Van Ittersum et al (2013)

o Anticipated world population by 2050 o Closing the ‘yield gap’ on currently available agricultural lands

Concept of production ecology

Definitions

Yield potential (Potential yield) - Yp: yield of a crop cultivar under defined weather conditions, when grown with no nutrient and water stress and biotic stresses effectively controlled

Water-limited yield - Yw: same as Yp, but water supply is limiting (and hence soil type and topography matter)

Actual yield – Ya: yield achieved by farmers in a given region under dominant management practices and soil properties

Yield gap – Yg: difference between Yp (or Yw) and Ya

Van Ittersum et al., 2013. Field Crops Research 143, 4-17.

Major steps for Yield gap analysis

Step 1: Measuring

Main reason for this step: To identify the potential

scope for raising average yields via management changes

Commonly used methods for Yp:

o Crop growth models o Field experiments o Best farmers yields o Highest recorded yields o Earth Observation o ....... Source: GYGA

Main reason for this step: To identify the key causes of the yield gap

Commonly used methods: Statistical models, qualitative analysis, Frontier methods ....

Explaining yield gap: Step 2

Which factors to collect?

Meta-analysis

Study locations included in Meta-analysis

270 records with unique ID

Results: Management factors

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Results: Edaphic factors

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Results: Farm characteristics

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Results: Socio-economic factors

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How to bridge the data gap? A potential answer—let the farmers tell us themselves!

Most of the management,

farm characteristics and

socio-economic factors that

explain yield gap cannot be

obtained by other means

other than asking the farmers

themselves- either by

traditional farm survey

methods or by through self-

reporting (e.g. SMS)

Example

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Farmers’ soil quality score “Clearly the farmers were aware of their

soil”

U.Sopheap et al., 2012

Crowdsourcing

o The term Crowdsourcing was first coined in 2006

o It commonly refers to outsourcing a function done locally to

a large, disconnected group of people.

In the Context of Agriculture:

“Crowdsourcing is when information is sourced from a group of people (e.g. farmers) in response to an open call, a request for specific information (e.g. crop/farm mgmt. information), or for an exchange, organized by a central organizer/organizing body. ” (USAID, 2013)

Typology of Crowdsourcing

Type How it works Kinds of problems

Examples

Knowledge Discovery and Management (KDM)

Finding and collecting information

into a common location and format

Information gathering, organization, and

reporting

Geo-wiki OpenStreetMap

RANET iCow

CCI-Bioversity

Distributed Human Intelligence Tasking

(DHIT)

For analysing large amounts of

information

For problems involving large-scale data

analysis

FoldIt, GalaxyZoo

Broadcast Search

Solving empirical problems

Ideation problems with empirically provable

solutions, such as scientific problems

Amazon Mechanical Turk

Peer-Vetted Creative

Production

For creating and selecting creative

ideas

Ideation problems where solutions are matters of taste or market support, such as design or aesthetic

problems

Istockphoto Threadless

Brabham, 2013

Case studies

Use of satellite images for Yield gap analysis

The use of satellite data for crop yield gap analysis : to estimate the actual yield

MSc topic: The use of smart phones and satellite

images for crop yield gap analysis

The main objective of this MSc topic is:

To explore the potential of satellite images to estimate important parameters (e.g. crop phenology, sowing date, actual yield etc.) that are relevant for yield gap analysis.

Thank you for your attention

Photo by Arun