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The Chemistry and Fertility of Soils under Tropical Weeds 59

and primary forest (Salam et al., 1998b). The influence of deforestation on the
activities of acid and alkaline phosphatases, urease, and -glucosidase in West
Lampung, Indonesia, is shown in Table 4.4. These findings are consistent with the
finding by Acosta-Martinez et al. (2007) from North Central Porto Rico (Caribbean)
that the activity of -glucosidase was greater in: forest = pasture > agriculture
lands. These findings are also consistent with the previous findings by Trasar-
Cepeda and Gil-Sotres (1988). They report that the activity of acid phosphatase
was higher in woodland (forest) than that in meadow (secondary forest) and
cornfield (cultivated land). More than two decades ago, Ho (1979) also reports
that the activity of acid phosphatase was significantly greater in soils of pure red
alder and red alder–Douglas-fir forests than that in pure conifer forests or in the
pasture. Garcia-Morote et al. (2012) also observe in semi-arid Mediterranean
ecosystems of southern Spain that mature woodland showed higher enzymatic and
microbiological activities than the younger woodland; the advanced communities
of Juniperus trees and Rosmarinus shrubs exhibited higher enzymatic and microbial
activities than did grasslands.
Several other researchers also report some supporting findings. Acosta-
Martinez et al. (2008) reports that the activities of some soil enzymes (i.e. -
glucoaminidase, -glucosidase, alkaline phosphatase, and arylsulfatase were higher
(up to 4-fold) in soil under pasture and under trees compared to the soils for
vegetable production, related to the higher soil organic C in parture (2-3-fold) and
mango (Mangifera indica) tree (1.6-fold) compared to soil under vegetable
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production (15.8 g kg ) and quenepas (Melico bijugatus) trees (15.9 g kg ). Speir
et al. (1980) observe that the degradation of sulfatase in planted soils were slower
than those in fallowed soils. They argue that this phenomenon was related to the
enzyme temperature-dependent denaturation in the fallow soils.
The activities of enzymes like phosphatases in forest soils were higher than
those in agriculture lands (Sakai and Tadano, 1993; Salam et al., 1997d; 1998b).
Previously, Duxbury and Tate III (1981) show that, compared to a fallow field, the
activities of some soil enzymes were significantly enhanced by grasses and
sugarcane plants. Some researchers also show that the activities of alkaline and
acid phosphatases were higher in the root zones and decreased to the directions of
bulk soils uninhabited by plant roots (Joner and Jakobsen, 1995). Reddy et al.
(1987) show higher activities of several soil enzymes in the rhizosphere soils than
those in the non-rhizosphere soils. Rao et al. (1990) also report that rhizosphere
soils showed higher activities than other soils: 26–158% for acid phosphatase, 66–
264% for alkaline phosphatase, and up to 292% for dehydrogenase. Salam et al.

Abdul Kadir Salam and Nanik Sriyani – 2019