Visiting the methodological aspects of flooding experiments: Quantitative evidence from agricultural and ecophysiological studies

Plant responses to flooding have been studied and reviewed extensively. However, the differences among the experimental procedures used to apply the flood that lead to such responses have never been explored. In this work, a database of 132 articles was created to quantify important methodological aspects of flooding experiments in crop and non-crop species for the first time as well as to look for thematic gaps in our knowledge on flooding research. Results showed that the flood experiments were conducted differently for crop and non-crop species, with two main distinctions: the duration of the flood and the consideration of competition among plants. For crop species, experimental flooding had a short duration of 16 days (ranging from 8 to 28 days for the 25th and 75th percentiles), while for non-crop species, flooding was quite longer, nearly 45 days (ranging from 28 to 61.5 days). Also, 53 % of the examined experiments in crop species considered competition among plants in their experimental protocol, while only 20 % did so for non-crop species. Regarding the topics least investigated within this area, in terms of both crop and non-crop species, future investigation should focus on the effects of flooding on reproductive traits, mineral nutrition and the nitrogen fixation of plants. These results are discussed, along with their implications in terms of defining crucial aspects of the methodology of flooding experiments.