Fig. 3
Leaching of nitrogen (N) as nitrate (NO3--N) (a–c) and phosphorus (P) as phosphate (PO43--P) (d, e) with and without nutrient inputs to gardens. Violin plots of growing season leachate, where the top panel shows N and the bottom shows P. Y-axis values are on a log base 10 scale. The box and whisker plot inside each shaded area shows the median (middle horizontal line), the interquartile range (the box), 1.5 times the interquartile range (vertical lines), and outliers (dots). The width of the shaded colored area represents the density of data points for each given value. The number of data points is different in each dataset as the nature of each research project was different; the controlled study had 168 no input and 728 input plot year points for both N and P, the semi-observational study had 44 plot year points with no input and 47 with inputs, finally the observational dataset had 8 plot year points with no N input and 85 with inputs while it was 9 without inputs for P and 84 with inputs. Using a non-parametric Wilcox rank sum test, we can see significant differences between no input vs input groups for the semi-observational and controlled projects (significance level via p-values in e, c, f). Colors match Supplementary Figs. 1, 3, 4, and 5.
