As far as I can tell, there are four things that can happen to the water: - it runs off or trickles away - probably negligible here - it evaporates before it'

As far as I can tell, there are four things that can happen to the water: - it runs off or trickles away - probably negligible here - it evaporates before it's absorbed by the plant - mostly due to wasteful irrigation practices. Unless you're doing drip-irrigation or similar, this is where most of your water will end up - it's absorbed by the plant and used in photosynthesis to make sugar and eventually other molecules - this is what's on the truck, but by mass it's negligible - it's absorbed by the plant and used for nutrient transfer - this is what happens to most water plants consume. In simplified terms, capillary action drives water up the plant, bringing nutrients with it; evaporation removes water at the leaf so that new water comes in According to Wikipedia the last effect (Transpiration) accounts for 97–99.5% of water actually used by the plant [1] 1: https://en.wikipedia.org/wiki/Transpiration https://en.wikipedia.org/wiki/Transpiration