Who are you? Cory Whitney from the Rhein-Waal University of Applied Sciences. What Presentation did you find most interesting on the last day of Tropentag?... (read more) I really liked the presentation Wastewater Irrigation in two South Asian Settings -- Is the Negative Perception of the Practice Justified?. I thought it was interesting because the presenter [Phillip Weckenbrock] challenged some more emotional arguments against the use of sludge and household waste waters in agricultural systems. There's a real negative response against waste water in agricultural use -- to waste water being smelled and seen when it's used on farms. So people tend to reject it from a personal and even a political perspective. In one area they even made it illegal and people were arrested for continuing to use waste water but it's free and extremely good fertilizer. But what about the concerns of heavy metals or pathogens that may be in the waste water that could lead to the transfer of disease when used in arable crop production? He also challenged these assumptions by testing the stool samples of people living along these rivers -- these waste water sources and users of these waster waters and they found no significant pathogens within these samples. And the other fact was that when the waste water is used the farmers get higher yields, higher incomes, a higher diversity of crops on their fields and they don't have higher instances of things like intestinal parasites or these kind of problems. What's also interesting is that the farmers were fighting to keep the ability of using the waste waters. What do you find interesting about all these findings? If we're really interested in sustainable farming systems then we should be focusing on closed nutrient cycles. We're always flushing valuable nutrients away and I think we should just forget our biases that poop and pee is gross and instead realize that these things are valuable for crop growth and the nutrition of people. Interested in more of Cory's perspectives? Then head over to his blog at http://www.corywhitney.blogspot.de/