Abstract:
An investigation on the chemical properties of Poonthalpadam soils of Kerala
shows that these soils have a pH range of 6.5—8.4. .The total nitrogen content
is low in most of the profiles studied. While the level of total P205 is found to
be satisfactory, the available phosphorus content is low probably due to the fact
that the P is present in combination with calcium and clay in rather unavailable
forms. Tne level of available potassium also is unsatisfactory which warrants
potash fertilization. Cation exchange studies reveal that calcium is the predominant
cation and 67 percent of the CEC is satisfied by the divalent cations, calcium
and magnesium. Sodium is also found to be present in the exchangeable form and
in some cases its content exceeded that of magnesium. The poor physical characteristics
can be attributed to the presence of sodium, which causes dispersion of
clay, and also to the high water table. Organic matter is found to be higher in the
surface layers because of the illdrained condition and the wide C/N ratio noticed
in some profile samples is possibly due to loss of nitrogen by denitrification and
persistence of organic matter due to anaerobic condition.
Improvement of the drainage and ameliorative measures for alkalinity are
necessary for the reclamation of these soils.
