Welcome to the 4th Edition of Global Conference on AGRICULTURE AND HORTICULTURE in Rome. The biggest obstacle to improving food security is floods and droughts caused by climate change. Since the first edition the AGRI conference has launched a new discipline in Water Science-- suitaiology--innovated by the WNEC Foundation. Applying a “Long, Broad, High and Deep" research thought and working mindset, suitaiology advocates for comprehensive solutions to flood disasters and water shortages in the long-term interests of sustainable agricultural development. It profoundly opens up a new perspective that in the Water-Human-Environment (WHE) system the natural situation of water is destructive, and achieved through dimensionality reduction attacks. We need to examine this asymmetric competition with dynamic natural forces from a level higher than the WHE system. Once we fully understand it, it's easy to find a suitable solution. The research in suitaiology should help inspire us on how to grasp core issues when we study dynamic changes, no mater which discipline. If existing theories are inadequate, we encourage you to contemplate creating a new theory to achieve your goals.