ation ▁and ▁storage ▁process ▁is ▁called ▁ens il age , ▁ens iling ▁or ▁sil aging , ▁and ▁is ▁usually ▁made ▁from ▁grass ▁cro ps , ▁including ▁ma ize , ▁s org hum ▁or ▁other ▁c ere als , ▁using ▁the ▁entire ▁green ▁plant ▁( not ▁just ▁the ▁gra in ). ▁Sil age ▁can ▁be ▁made ▁from ▁many ▁field ▁cro ps , ▁and ▁special ▁terms ▁may ▁be ▁used ▁depending ▁on ▁type : ▁o at lage ▁for ▁o ats , ▁hay lage ▁for ▁al f alf a ▁( h ay lage ▁may ▁also ▁refer ▁to ▁high ▁dry ▁matter ▁sil age ▁made ▁from ▁hay ). ▁ ▁Sil age ▁can ▁be ▁made ▁by ▁one ▁or ▁more ▁of ▁the ▁following ▁methods : ▁placing ▁cut ▁green ▁veget ation ▁in ▁a ▁sil o ▁or ▁pit ; ▁p iling ▁the ▁veget ation ▁in ▁a ▁large ▁heap ▁and ▁compress ing ▁it ▁down ▁so ▁as ▁to ▁pur ge ▁as ▁much ▁o xygen ▁as ▁possible , ▁then ▁covering ▁it ▁with ▁a ▁pl astic ▁sheet ; ▁or ▁by ▁wrapping ▁large ▁round ▁b ales ▁tight ly ▁in ▁pl astic ▁film . ▁ ▁Production ▁ ▁The ▁cro ps ▁most ▁often ▁used ▁for ▁ens il age ▁are ▁the ▁ordinary ▁grass es , ▁clo vers , ▁al f alf a , ▁v etch es , ▁o ats , ▁r ye ▁and ▁ma ize . ▁Many ▁cro ps ▁have ▁ens il aging ▁potential , ▁including ▁pot atoes ▁and ▁various ▁we eds , ▁not ably ▁sp ur rey ▁such ▁as ▁S per g ula ▁ar v ensis . ▁Sil age ▁must