Vegetation influence on soil quality in a highly degraded tropical ...
Vegetation influence on soil quality in a highly degraded tropical ...
Vegetation influence on soil quality in a highly degraded tropical ...
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TABLE 1. <str<strong>on</strong>g>Vegetati<strong>on</strong></str<strong>on</strong>g> effects <strong>on</strong> <strong>soil</strong> physical and chemical properties. Values for each <strong>in</strong>dividual species and c<strong>on</strong>trol are the means averaged<br />
across depth and time.<br />
Species Group<br />
Volumetric<br />
water c<strong>on</strong>tent pH<br />
Exchangeable<br />
bases<br />
Exchangeable<br />
acidity Exchangeable Al<br />
Effective cati<strong>on</strong><br />
exchange capacity<br />
cm3 /100 cm3 - - - - - - - - - - - - - - - - - - - - - - - - cmolc /kg - - - - - - - - - - - - - - - - - - - - - - - -<br />
A. procera Legume trees 41.14 c1 4.66 3.03 4.15 3.92 7.18<br />
A. <strong>in</strong>ermis 41.26 bc 4.46 1.23 6.99 6.64 8.23<br />
B. humidicola Grasses 45.97 ab 4.72 3.55 3.91 3.63 7.46<br />
H. altissima 47.26 a 4.56 2.52 4.48 4.28 6.99<br />
A. glabrata Legume shrubs 40.95 c 4.50 1.62 5.80 5.50 7.42<br />
C. acutifolium 40.77 c 4.46 1.75 5.60 5.31 7.36<br />
C<strong>on</strong>trol Bare <strong>soil</strong> 40.11 c 4.45 1.35 6.25 6.95 7.59<br />
F-test * NS NS<br />
C<strong>on</strong>trasts<br />
NS NS NS<br />
<str<strong>on</strong>g>Vegetati<strong>on</strong></str<strong>on</strong>g> vs. bare <strong>soil</strong> ND2 ND ND 5.313 5.18<br />
NS<br />
6.25<br />
6.95<br />
4<br />
Legumes vs. grasses ND ND ND 5.64<br />
5.34<br />
NS<br />
4.20<br />
3.96<br />
Grasses vs. bare <strong>soil</strong> ND ND ND 4.20<br />
3.96<br />
NS<br />
6.25<br />
6.95<br />
Legumes vs. bare <strong>soil</strong> ND ND ND 5.64<br />
5.34<br />
NS<br />
6.25<br />
6.95<br />
1 Means with different letters with<strong>in</strong> a column are significantly different at P < 0.05 us<strong>in</strong>g Fisher’s protected LSD.<br />
2 ND denotes c<strong>on</strong>trast was not determ<strong>in</strong>ed.<br />
3 C<strong>on</strong>trast means are significantly different at P < 0.05.<br />
4 NS denotes n<strong>on</strong>-significance at P < 0.05.<br />
J. Agric. Univ. P.R. VOL. 88, NO. 1-2, JANUARY-APRIL 2004 17