From the world new web site an article from the N.Z. Herald. co.nz by steve conor oct 22:
"Race to feed extra billions" says world food production need to be increased by between 50% to 100% by 2050 in order to avoid wide spread famine. 3 billion more people are expected by 2050 it says major challenges are in water for irrigation, and soil degradation. The link between water and food is major so companies to desalinization and irrigation equipment are likely major growth areas, of course the infrastructure to treat and supply water and treat waste water for an additional 3 billion are significant as well. So thats the trend.