Ambio 22: 417-426. soil organic matter and acid soils predominate. case in many of the soils inthe warm-humid tropics. of agricultural and charcoal production. cut and burned to allow planting of crops. cycles before the land has to revert back to fallow. and added to soil.
It's important for adults 40 and older to have eye exams every 2 to 4 years to check for problems. Those who have a history of eye problems or who are at risk for developing them should see an eye doctor every year. This is particularly important if you have risk factors or a family history of eye problems.
Eye exams are an essential part of your overall health. If you wear glasses or contacts, you should have a comprehensive eye exam annually. Even if you donât think you have any vision problems, you should get an eye exam every two years to check for any problems that might have developed.