 |  | | |
  | Northeast China |
| |
   | Northeast India & Bangladesh |
|  |
  | Northern Great Plains |
| |
|
|  |
  | Northwest China |
| |
|
|  |
  | Southeast Asia |
| |
|
|  |
  | Southeast U.S. |
| |
   | Southern and Eastern Russia |
|  |
  | Southern India & Sri Lanka |
| |
|
|  |
  | Southwest China |
| |
|
|  |
  | Western India |
| |
|
|  |
 | nutrient removal |
| |
|
|  |
  | Eastern Canada & Northeast U.S. |
| |
|
|  |
  | Northcentral U.S. |
| |
|
|  |
  | Southeast Asia |
| |
|
|  |
  | Southern and Eastern Russia |
| |
   | Southern India & Sri Lanka |
|  |
  | Western Canada |
| |
|
|  |
 | nuts |
| |
|
|  |