ggplot geom-line and geom_bar colors

I have a dataframe and I'm trying to plot a line and a bar in the same plot. I also need a legend. I got the barplot to show the desired color but is more of an added outline than a color, and it shows an horizontal line at y=zero that I would like to remove.

Any help is appreciated!

here is my code:

windows()
ggplot(data = rr, aes(x = date))+
  geom_point(aes(y=value, colour="Nitrogen"))+
  geom_line(aes(y=value, colour="Nitrogen"))+
  facet_grid(depth~dose) +
    geom_bar(data=rr,stat = "identity", position = position_dodge(width = 0.9),aes(x=date, y=rain100 ,colour="Rains"))+
  theme(strip.text.x = element_text(size = 7, colour = "black", angle = 0),axis.text.x = element_text(angle=90,vjust=0.5,hjust=0.5, size=8))+
  ylab("Soil nitrogen measured as nitrate, lb/ac and rains, 100ths of inch")+
  scale_x_date(date_breaks = "1 month",date_labels = "%m-%d-%y")+
  ggtitle("MR Ranch")+
  ylim(0,350)+
  scale_colour_manual("",
                      breaks=c("Nitrogen","Rains"),
                      values=c("black","blue"))

here is (a shortened version of) my dataset

    structure(list(date = structure(c(17444, 17444, 17444, 17444, 
17456, 17456, 17456, 17456, 17457, 17457, 17457, 17457, 17473, 
17473, 17473, 17473, 17485, 17485, 17485, 17485, 17508, 17508, 
17508, 17508, 17550, 17550, 17550, 17550), class = "Date"), depth = c("12-24 in", 
"12-24 in", "0-12 in", "0-12 in", "12-24 in", "0-12 in", "0-12 in", 
"12-24 in", "12-24 in", "12-24 in", "0-12 in", "0-12 in", "0-12 in", 
"12-24 in", "0-12 in", "12-24 in", "0-12 in", "12-24 in", "0-12 in", 
"12-24 in", "12-24 in", "0-12 in", "0-12 in", "12-24 in", "12-24 in", 
"0-12 in", "0-12 in", "12-24 in"), value = c(60, 60, 60, 60, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, 50, 20, 12, 69.5, 
87, 30, 347, 12, 35, 17.4, 35, 35), trt = c("Experiment", "Control", 
"Control", "Experiment", "Control", "Control", "Experiment", 
"Experiment", "Experiment", "Control", "Control", "Experiment", 
"Experiment", "Experiment", "Control", "Control", "Experiment", 
"Control", "Control", "Experiment", "Experiment", "Control", 
"Experiment", "Control", "Experiment", "Control", "Experiment", 
"Control"), dose = c("High Preplant", "Low/No Preplant", "Low/No Preplant", 
"High Preplant", "Low/No Preplant", "Low/No Preplant", "High Preplant", 
"High Preplant", "High Preplant", "Low/No Preplant", "Low/No Preplant", 
"High Preplant", "High Preplant", "High Preplant", "Low/No Preplant", 
"Low/No Preplant", "High Preplant", "Low/No Preplant", "Low/No Preplant", 
"High Preplant", "High Preplant", "Low/No Preplant", "High Preplant", 
"Low/No Preplant", "High Preplant", "Low/No Preplant", "High Preplant", 
"Low/No Preplant"), rain = c(0, 0, 0, 0, 0, 0, 0, 0, 0.01, 0.01, 
0.01, 0.01, 0.09, 0.09, 0.09, 0.09, 0, 0, 0, 0, 0, 0, 0, 0, 0.03, 
0.03, 0.03, 0.03), rain100 = c(0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 
1, 1, 9, 9, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 3, 3)), row.names = c(NA, 
-28L), class = "data.frame")

Solution

The key is to use fill and not color. The code will generate a warning but will display correctly. Verify if the legend the expected result.

library(ggplot2)

ggplot(data = rr, aes(x = date))+
  geom_point(aes(y=value, fill="Nitrogen"), colour="black")+
  geom_line(aes(y=value,  fill="Nitrogen"), colour="black")+
  facet_grid(depth~dose) +
  geom_bar(data=rr,stat = "identity", position = position_dodge(width = 0.9),aes(x=date, y=rain100, fill="Rains") )+
  theme(strip.text.x = element_text(size = 7, colour = "black", angle = 0),axis.text.x = element_text(angle=90,vjust=0.5,hjust=0.5, size=8))+
  ylab("Soil nitrogen measured as nitrate, lb/ac and rains, 100ths of inch")+
  scale_x_date(date_breaks = "1 month",date_labels = "%m-%d-%y")+
  ggtitle("MR Ranch")+
  ylim(0,350) +
  scale_fill_manual(labels=c("Nitrogen","Rains"), breaks=c("Nitrogen","Rains"), values=c("black","blue"), name="")