Further to Where do I find the legend for netCDF files in QGIS?, I have .nc and .asc files of crop area and production for maize, rice and wheat. It says here, about QGIS importing .asc files:
QGIS has native support for this format. ESRI grid (.asc) files can be directly opened in QGIS by selecting Layers >>> Add Raster Layer. The .asc file can also be dragged and dropped into the QGIS session, rather than using the Add Raster Layer option.
But when I do either, I get this error:
.asc is not a supported raster data source.
which has been reported at Is .asc supported raster data source for QGIS?
I am using version 2.0.1-Dufour.