fig4

Figure 4. Spatial variation of soil parameters in three sub-districts. The boxplots illustrate the distribution of soil (A) total nitrogen, (B) phosphorus, (C) potassium, and (D) electrical conductivity. The median and mean values of these parameters are represented by a solid line and a red circle within each box, respectively. The whiskers extend to the minimum and maximum values, excluding any outliers, which are displayed as individual data points outside the whiskers. The P-value obtained from the Kruskal-Wallis test indicates the level of significance in the observed variations of soil nutrient and salinity levels among the different sub-districts. The letters (a, b, and c) on the boxes indicate the significant differences in pairwise comparisons (e.g., Assasuni-Dacope) of soil nutrients and salinity. Asterisks (* and **) above the boxes signify the significance (P < 0.05 and P < 0.001) of the differences in the studied variables in each sub-district compared to their base mean (i.e., mean values of all sub-districts), which were derived using the Wilcoxon test, whereas the symbol "ns" represents the differences are insignificant. The dashed lines within the plots indicate the mean values of the studied variables in three sub-districts.