water

Conservation of water (2002) and a special stamp use for greeting cards (2013).  Bamboo is especially good at conserving water. Once it is established it can get all the water it needs from the ground and can help with soil erosion.

For more water, here is one from the Beautiful China series (2013) showing Xing Hua Duo Tian Agrosystem and the islands of rapeseed flowers (for canola oil). This is a unique land water use where raised cultivated fields surrounded by irrigation canals are made from the sludge. 

and, because this is apple season...

for Sunday Stamps - Asia