SDI 4 Apps - Uptake of open geographic information through innovative services based on linked data

Yield potential zones are areas with the same yield level within the fields. Yield is the integrator of landscape and climatic variability and therefore provide useful information for identifying management zones. This presents a basic delineation of management zones for site specific crop management, which is usually based on yield maps over the past few years. The presence of complete series of yield maps for all fields is rare, thus remote sensed data are analysed to determine in field variability of crops thru vegetation indices.

The below described process of the FOODIE platform aims at establishing a general model for yield potential zones for almost any kind of crop. However, such universality comes at a price. The model is capable to express significant spatial variations of a crop yield on a plot when distinguishing three kinds of values: below average, average and excessing average. On the other hand, the model depicts spatial variations within a plot and therefore may be misleading when trying to compare yield zones between plots. Simply said, we may conclude that some area(s) in a plot has significantly lower productivity then another and take such information into the decision making process. On the contrary, we cannot define that it is better to produce a crop on a plot A or a plot B.

As the main data source, ESPA repository of LANDSAT TM and OLI images on USGS website is used, which offers surface reflectance products, main vegetation indices (NDVI, EVI) and clouds identification by CFmask algorithm. A selection of scenes from recent 8 years is made for farm area to collect cloud-free data related to second half of vegetation period. Yield potential is calculated for separate scenes as the relation of each pixel to mean value of whole field. In last step all scenes are combined and median value of yield potential is calculated. After fully operation of Sentinel 2A/B satellites, calculation of yield potential will be enhanced by these vegetation products.

During Hackathon we plan demonstrate this approach on Latvian farms.

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