Ma'anar ƙamus na "tushen bullowa" yana nufin wani nau'in tushen da ke tsiro daga tushe ko ganyen shuka maimakon tushen tushensa. Tushen haɓaka sau da yawa ana samun su don amsa wasu abubuwan muhalli kamar ambaliya, fari, ko rauni ga babban tushen tushen. Za su iya taimaka wa shukar ta dage kanta cikin aminci a cikin ƙasa ko kuma ta sha abubuwan gina jiki da ruwa yadda ya kamata. Misalai na tsire-tsire masu tushe masu tasowa sun haɗa da ivy, masara, da rake.