Madagascar - Antsirabé

Operational Implementation Plans

Data Collected for Crop Characterization

Field surveys were conducted in the study zone during the growing peak (end of February) of the 2014-2015 cropping seasons in order to characterize the main cropping systems. A total of 1020 GPS waypoints were registered in the study area, chosen according to their accessibility and to be as well representative of the existing cropping systems as possible. The data gathered during the field surveys concerned farmers’ practices (type of crop, use of fertilizers and irrigation). GPS waypoints were also registered on different types of non-cropped classes (natural vegetation, urban areas, water bodies…) to obtain data on the non-crop class. 199 additionally points were added to the field database for non-crop class by photo interpretation of PLEAIDES very high resolution imagery, making a total of 1219 points finally usable (860 cropped and 359 non-cropped). The boundaries of the fields (for cropped classes) / objects (for non-cropped classes) were then digitized over PLEAIDES very high resolution imagery in order to obtain a polygon database.

Table 1 presents the number of polygons per type of class for the more detailed level (Sub Class) of the JECAM nomenclature. Green is cropped, and grey is non cropped. The map of the GPS waypoints acquired over the Antsirabe JECAM Site over 2014-2015 growing season is presented in Figure 1.

Table 1   Number of Polygons per Type of Class in the Field Database for Sub-class of JECAM Nomenclature


Figure 1   Map of the GPS Waypoints Acquired over the Antsirabe JECAM Site over 2014-2015 Growing Season

Data Collected for Estimate of Crop Production

During 2015 harvest season, 124 rice fields (88 irrigated, 36 rainfed) were sampled in order to obtain information on the farmers’ practices (cultivar, planting date, irrigation, fertilization, harvest date) and the yield (total biomass, dry biomass, full and empty grain yield on two plots of 1m² inside the field). The map in Figure 2 presents the location of the 2015 yield surveys.

Figure 2   Locations of 2015 Field Surveys

Plans for Next Growing Season:

The same approach will be maintained for the next growing season but with time series of Sentinel-2 images (preprocessed by the CNES MUSCATE processing chain to obtain images in top of canopy reflectance and monthly synthesis free from clouds) and SPOT 6/7 images for the very high spatial resolution of the site during the peak of the growing season.

We anticipate ordering the same type/quantity of EO data next year. 

©2015 Joint Experiment for Crop Assessment and Monitoring