What does your Boruta function call look like? There are two correct ways to call Boruta::Boruta, with and without a formula:

dataset that has variables "var1", "var2" and "Response".

dataset_x = dataset[,1:2] # "var1" and "var2" as the dataframe dataframe_x

dataset_y = dataset[,3] # "Response" as the vector dataset_y

Boruta(x = dataset_x , y = dataset_y ) # This works

Boruta(Response ~var1+var2, data = dataset) # This works too

Aki Koivu , Thanks for your reply

My boruta functions look like

Boruta(nematode abundance data, soil data, doTrace=2, pValue=0.05)

Actually there are two different datasets. Nematode abundance data contains 58 different species abundance from 501 locations, while soil data contains 13 soil variables from those 501 locations. Now I want to select important soil variables affecting nematode community.

Thanks