Conservation agriculture (CA) has been advocated by many scientists as the solution for sustainable agricultural production. Indeed, finding of many research project support it and it can also be seen at Poster Sessions of Tropentag2014, where successful examples were given: applying no-tillage farming had a positive influence for Acrisols in Brazil, mulching application in Kenya provided better water retention or combination of technics increased yields in Mexico. However, a case study from R. Romero-Perezgrovas says, that on 6% of increase in soil fertility on the one hand, farmer would get 50% weeds in his field. (Continue...)