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.
It is important to have your eyes examined regularly. Your eyes should be tested: before age 40, every two to four years. from age 40 to age 54, every one to three years. from age 55 to 64, every one to two years. after age 65, every six to 12 months.