Lewis & Short

siccānĕus, a, um, adj. [siccus] (a technical word of Columella); of soil, dry, of a dry nature: genus prati (opp. riguum), Col. 2, 16, 3: locus (opp. riguus), id. 4, 30, 5; 11, 2, 71.
Neutr. plur. absol.: de siccaneis et riguis non comperimus, dry places, Col. 2, 2, 4.