Question

what are the reasons for high production in japan?

Answer 1

Hello dear,
You didn't mention production of what here. As Japan is widely known for its rice production I'll assume you're talking about that.

# Rice production is high in Japan because-
- abundant amount of rain
- mild and humid climate
- improved varieties of rice
- organization of resources
- traditional techniques

Hope this is useful...

Answer 2

"Agriculture exist is every region of Japan.  Crop production is extremely important in Japan and  rice is the highly produced crop in Japan.

Rice is produced densely in Japan because of temperate climate adequate rainfall, soil fertility, modern equipment, techniques and terrace production of  the rice and other crops that is being able to develop intensive cultivation.    

Japan has also seen highest degree of industrialisation in Asia.

"