How about a corn knife?
https://www.amazon.com/Seymour-2C-66-Corn-Knife/dp/B00004RADY
Or a "ditch knife" (in two sizes)
https://www.grainger.com/product/12N147?gclid=EAIaIQobChMI4dD_gL7s6wIVfz2tBh2aqQe1EAQYAiABEgLN2PD_BwE&cm_mmc=PPC:+Google+PLA&ef_id=EAIaIQobChMI4dD_gL7s6wIVfz2tBh2aqQe1EAQYAiABEgLN2PD_BwE:G:s&s_kwcid=AL!2966!3!264955915865!!!g!439063557338!&gucid=N:N:PS:Paid:GGL:CSM-2295:45Q7YX:20500731