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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
                                                                                       -1
                                            -1
                           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
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