Soil nitrogen changes in farming systems in the humid tropics
- Biological Nitrogen Fixation in Farming Systems of the tropics, p.27-42, 1977 .
The available information shows: (1)that rather large quantities of nitrogen are contained in fallow vegetation and underlying soil ant that upon clearing the fallow large amounts of nitrogen era mineralized; (2)That leaching processes are not such thata the nitrate is rapidly moved out of the soil and sub-soil; (3)that there is no good evidence for or against the proposition that the ordinary arable crops are shallow feeders and the fallow vegetation has deep root systems; since soil dry out in the dry season there are some plant covers which indicate more nitrate in sub-soils under arable than fallow conditions; and (4)no data were found which would negate the hypothesis that sub-soil nitrogen is an important component in the nitrogen cycle in the tropics