Some preliminary results show correlations with iron, manganese, and sulfur, but not phosphorus of four sampling dates at The Intervale Community Farm.
Click image to enlarge.
Each X axis label corresponds to a date:
1=May 3, 2012: after snow melt
2=Oct 18, 2012: before Saturation
3=April 5, 2013: before saturation
4=July 4, 2013: after saturation
The Y axis is the p-value. There is better statistical significance the closer the point is to zero. For example, sulfur shows a higher correlation with length of water saturation/elevation and less correlation in-between dates of high saturation. Iron is an even more extreme example of this. There is almost no iron/elevation relationship during sampling dates that are not after saturation. This may be due to field management practices like discing that redistribute nutrients evenly. On the other hand, manganese is the most muted form of this trend.
Phosphorus tells a surprising story. Considering the relationship between phosphorus and iron, I would expect phosphorus to follow a similar trend to the other nutrients included on the graph. One possible reason may be that vegetation is larger at higher elevations given more favorable growing circumstances (less saturation=more aeration=less environmental stress) and since the crops are larger up-slope, they seek out and acquire more phosphorus, encouraging a relationship between elevation unrelated to length of saturation and phosphorus in soil.
floodedsoils 