This is the standard Ukiyo-e Terrain recoloured to give an orange colour, similar to the ground colour used in the Battle of Anegawa screen.
See here;

This will only work if you have updated your version of Sengoku Jidai to at least the 1.2.8 patch, that added the capability to have extra terrain styles.
I have also modified the Objects Textures files slightly to give more vibrant colours to the trees.

How to Install:
1) Download the file:
https://www.mediafire.com/?pcqc29fx4s3gc1z
2) Extract the file:
3) Within the file you have extracted you will find two sub folders;
Data; Copy and paste the Data file into your ProgramFiles (x86)/Slitherine/Sengoku Jidai (Steam version: /ProgramFiles (x86)/Steam/SteamApps/Common/Sengoku Jidai). Click OK to overwrite any existing files.
ORIGINAL OBJECTS; This contains the Original Sengoku Jidai Object Texture files. As the Data file overwrites the original Object Texture files, I have included them here just in case you want to revert back to them.
4) Unlike the standard terrain options (Ukiyo-e and Green) this additional terrain set cannot be selected from the in-game Options screen. So find your Sengoku Jidai OPTIONS.TXT file. Mine is located in My Documents/My Games/SJIDAI, but yours may be different depending upon what version of Windows you have. Open the OPTIONS.TXT and change the AltTiles line to read AltTiles 16.
Cheers
Paul