Combined graph: line and histogram with ggplot2

[totti_dici]

I finally succeeded by forcing the y-axis to 0 when all values are positive or negative.
I also added a margin to the x-axis labels to avoid overlapping

 if(lim_ecart_max<0){lim_ecart_max=0}
  if(lim_ecart_min>0){lim_ecart_min=0}
  
  g2 <- df_prod_ecart_mensuel %>% 
    ggplot()+
    aes(x=mois,y=ecart, fill="ecart", label=ecart)+
    geom_text(aes(x=mois,
                  y=ecart, 
                  label=pct_ecart, 
                  vjust = 0.5 - sign(ecart)/2, hjust=0.5),
              size=1.5,
              color="black",
              fontface="bold")+
    geom_col(width = .5, alpha=0.5)+
    scale_fill_manual(breaks = c("ecart"),
                      values = c("blue"),
                      labels= c(paste0("écart","\n",N,"/",N_1))) +
    scale_y_continuous(labels = function (x) format(x,big.mark=" ", scientific = F))+
    scale_x_discrete(limits =as.factor(c(1:12)))+
    labs(y="Nb producteurs")+
    geom_hline(yintercept=0)+
    coord_cartesian(xlim =c(1, 12), 
                    ylim = c(lim_ecart_min, lim_ecart_max),
                    clip = "off")+
    theme_minimal()+
    theme(axis.text.y = element_text(size=8, face = "italic"),
          axis.title.y = element_text(size=8,face = "italic"),
          axis.text.x = element_text(size=8),
          axis.title.x = element_text(size = 8, hjust = 1),
          legend.text = element_text(size=7),
          legend.title = element_text(color="transparent")
    )