Young maize field. ©FAO/Teopista Mutesi

14 December 2021, Johannesburg – Monitoring crops from space in Southern Africa is about to get easier, thanks to the newly introduced use of satellite Earth Observations by NASA Harvest – NASA’s Food Security and Agriculture Program in partnership with Food and Agriculture Organization of the United Nations (FAO).

The two institutions kicked off a series of training for national and regional agencies and FAO country offices in Southern Africa in the use of Earth Observations (EO) Indicators for application to agricultural monitoring to support in regular monitoring activities and to enhance the capacity for anticipatory action.

Participants were taken through the applications of agrometeorological EO indicators for agricultural monitoring including an introduction to the different indicators available, and examples of how EO indicators are applied to derive insights about agricultural conditions.

“The EO indicators used for agricultural monitoring best serve as early warning through their ability to monitor crop health and environmental stressors, and exactly at which point we need to activate anticipatory action initiatives,” said Merzouk, Quraishia, Early Warning Anticipatory Action Specialist at Johannesburg-based FAO Resilience hub.

Understanding impact of weather on agriculture

The agrometeorological Indicators from Earth Observations (EO) provide critical information to monitor and track crop conditions throughout a growing season. This is even more critical in areas where access to field information is limited and smallholder agriculture dominates.

“The vast knowledge provided through training builds In-country expertise in new technologies and methodologies to support FAO regional and global collective goals to achieve agriculture and food security,” said Pound, Jonathan, Economist at FAO Global Information and Early Warning System (GIEWS). 

In some cases, agrometeorological (Agmet) EO indicators like normalized difference vegetation index (NDVI), Precipitation, Temperature, Soil Moisture and Evaporative Stress Index among others, are often the first and even the sole source of information on crop conditions, allowing rapid and large-scale assessment of potential weather-related impacts on agricultural production throughout the growing season.

Agmet EO indicators are often used to identify anomalies that can be associated with potential agricultural impacts and used together can provide a robust basis for convergence of evidence of agricultural conditions for decision-makers.

"A major goal of NASA Harvest is to develop tools fed by Earth Observations that meet the needs of operational users. This training provided a great opportunity to put these tools we've developed in partnership with our user community into the hands of the anticipatory action communities to better support actionable crop assessments," said Christina Justice, one of the trainers from the NASA Harvest.

Application of EO Indicators

EO data obtained from satellites guide interpolations of temperature and rainfall observed at weather stations. The interpolated data can then be used to infer environmental stress during the growing season.

EO data like vegetation indices are also excellent proxies for crop health. EO data acquired from spaceborne, aerial and other platforms at different spatial, spectral, and temporal intervals has immensely improved the ability to monitor the condition of agriculture.

In many ‘countries at risk’, agrometeorological and remote sensing information is often the first and even the sole source of information on crop conditions, allowing rapid and large-scale assessment of potential weather-related impacts on agricultural production. Ends