Page 167 - Enzymes in Tropical Soils

Enzymes in Tropical Soils 155

enzymatic activities than did the control treatment with only coffee plants.
Paspalum conjugatum was also observed to give higher effects that did natural
vegetation. The same effect but with lower values was also observed in subsoils
(Salam, 1996; Salam et al., 2011).

Table 10.3. The changes in soil pH, organic C, total N, and available P of cassava
plantation in Gunung Batin Central Lampung Indonesia*.

Period of
Organic C Total N Available P
Cultivation pH -1 -1 -1
(g kg ) (g kg ) (mg kg )
(Years)
0** 4.7 43.0 2.60 5.03

1 - 5 4.5 20.0 1.00 24.7
6 - 10 4.4 12.8 0.80 7.70
*Adapted from Salam et al. (1999e); **Bushes adjacent to the plantation.

Table 10.4. The effects of vegetation on some soil chemical properties of coffee
plantations in West Lampung Indonesia*

Organic C Total N Available P
pH -1 -1 -1
(g kg ) (g kg ) (mg kg )
1997 1999 1997 1999 1997 1999 1997 1999

A. No Vegetation (Control)
Topsoil 4.00 3.49 23.1 21.1 1.80 1.50 6.05 2.78
Subsoil 3.87 4.27 11.7 7.8 0.90 1.10 4.67 3.48

B. Grass (Paspalum conjugatum)
Topsoil 4.94 3.87 30.5 29.2 1.30 2.70 4.67 3.52
Subsoil 4.66 4.89 26.1 26.9 2.00 1.90 4.67 3.11

C. Natural Vegetation
Topsoil 4.58 3.97 12.4 26.7 1.30 2.40 5.36 3.52
Subsoil 4.47 4.56 11.4 20.6 1.10 1,40 4.67 2.81
*Adapted from Salam et al. (2001)

Abdul Kadir Salam - 2014