SOIL PROPERTIES, CONDITION AND SOIL LOSSES FOR SOUTH AND EAST BRAZILIAN FOREST AREAS
relationship between SR and Feo/Fed ratio equal -0.56 (Table 4). However,
we considered besides Oxisols, less weathered soils, as Inceptisol. Usually,
Oxisols are composed predominantly of kaolinite, gibbsite, goethite and
hematite, which form extremely stable aggregates (Lima & Anderson, 1997;
Ajayi et al., 2009).
Studies performed under rainfall simulator showed that soils with
the highest clay content produced low runoff and a low sediment
concentration (Lado et al., 2004; Mamedov et al., 2002) due the large size of
the entrained particle (Mamedov et al., 2002). Thus, a combination of low
runoff and low sediment concentration in runoff resulted in smaller soil
losses. Nevertheless, soil loss data obtained through USLE-plots under
natural rainfall data compiled from Martins (2005), Oliveira (2006) and
Oliveira (2008), which encompassed the studied area did not show a
correlation with clay content (Table 4). However, soil loss showed a weak
relationship with silt content, which can produce surface sealing in bare soils
increasing runoff and then soil losses.
37
TABLE 4 Pearson correlation matrix of soil properties under eucalypt cultivated forest in Brazil.
SR MGD TP K factor AUSLE CEC OM Clay Silt Sand Fed Fes Feo/Fed Fed/Fes SiO2 Al2O3
SR 1.00
MGD 0.20 1.00
TP 0.03 -0.28 1.00
K factor -0.56 0.47 -0.67 1.00
AUSLE 0.33 0.03 -0.52 0.45 1.00
CEC 0.24 -0.15 0.81** -0.37 -0.20 1.00
OM 0.59 0.13 0.51 -0.36 0.22 0.84*** 1.00
Clay 0.63* 0.39 0.56 -0.87* -0.02 0.57 0.71** 1.00
Silt 0.17 -0.61 -0.02 -0.10 0.69* 0.25 0.37 -0.15 1.00
Sand -0.68* -0.14 -0.54 0.84* -0.26 -0.66* -0.85*** -0.92*** -0.26 1.00
Fed 0.39 0.15 0.61 -0.73 0.19 0.66* 0.77** 0.88*** 0.20 -0.94*** 1.00
Fes 0.35 0.02 0.82** -0.83* -0.11 0.75** 0.70* 0.84*** 0.05 -0.84*** 0.86*** 1.00
Feo/Fed -0.56 0.08 -0.47 0.99*** -0.20 -0.34 -0.43 -0.78** -0.16 0.82** -0.77** -0.77** 1.00
Fed/Fes 0.27 0.02 0.15 -0.57 0.55 0.33 0.52 0.49 0.49 -0.67* 0.77** 0.35 -0.53 1.00
SiO2 0.80** 0.51 0.31 -0.78 0.15 0.41 0.72** 0.93*** -0.12 -0.86*** 0.72** 0.69* -0.67* 0.37 1.00
Al2O3 0.56 0.45 0.58 -0.86* -0.13 0.60 0.68* 0.98*** -0.26 -0.86*** 0.83** 0.84*** -0.71** 0.41 0.89*** 1.00
SR = stability ratio; MGD = mean geometric diameter; TP = total porosity; K factor = soil erodibility; AUSLE = soil loss from
USLE-plots; CEC = cation-exchange-capacity; OM = organic matter; Fed = iron extracted by dithionite-citrate bicarbonate; Fes
= iron extracted by sulfuric attack; * = P < 0.1; ** = P < 0.05; *** = P < 0.01.
38
Despite not found a relationship between SR and soil losses, a negative
and weak correlation between SR and soil erodibility (K factor) can be noticed.
For kaolinitic soils (1:1 minerals), the trend between soil loss and SR was not as
significant and soil loss was more related to clay dispersibility (Levy & Miller,
1997), whereas, the same authors reported a linear relationship for soils with 2:1
type mineralogy. A high relationship was found between soil erodibility and
Feo/Fed ratio (Table 4). As the analyses were performed in the A horizon, the
biocycling of silica and the relatively higher amount of organic matter help to
explain the highest correlation found between these soil properties.
The soil OM did not show a relationship with SR (Table 4),
corroborating Levy & Mamedov (2002), and Levy et al. (2003). Kaolinitic (1:1
clay minerals) soils have variable charges and a coexistence of both positively
and negatively charged particles. If oxides, rather than soil OM, are the
dominant agents in aggregation stabilization in weathered soils, the relation
between soil OM and macroaggregation might not be as strong as the soils with
dominant 2:1 clays (Six et al., 2000b). In addition, in tropical soils dominated by
oxides and 1:1 minerals, a decrease of soil OM levels results in a smaller
decrease of soil stability when compared to soils dominated by 2:1 minerals (Six
et al., 2000a). Furthermore, soil OM not correlated with aggregate stability does
not imply that soil OM is unimportant in clayey soil structure, but its importance
is at a different level of structure (Reichert & Norton, 1994). The absence of a
relation between aggregate stability and organic matter content found in our
study could be ascribed to the fact that in tropical soils other soil properties may
have a greater impact on aggregate stability, and hence, overshadow the effects
of soil organic matter. The granular structure of tropical soils, which is
associated with a more oxidic mineralogy (Ferreira et al., 1999) in comparison
with the blocky structure of temperate regions soils, helps to explain such
differential OM behavior.
39
Besides stability ratio, soil OM can affect and be influenced by several
soil properties. Soil OM showed a positive relationship with clay content (Table
4). Clay particles can generate organic-mineral complex, which results in
accumulation of organic matter. Thus, an increase in clay content, both soil
surface area and organic matter increase (Scott et al., 1996).
In weathered soils, the mainly contribution on CEC is due to soil OM (in
most cases soil OM in studied soils was more than 3%) (Table 1), which can
generate a large number of negative charges. A significant relationship was
found between soil OM and CEC (Table 4). This way, well management
practices that protect soil OM are extremely important to keep soil fertility in
these environments. The aforementioned correlation was greater than between
CEC and clay content (Table 4). This fact strengthens the fact that in soils
dominated by 1:1 clay content and Al- and Fe-oxides, soil OM can be more
important than clay content for explaining CEC context. Levy & Miller (1997)
found a direct linear relationship between stability ratio and CEC. Thus, the
researchers could conclude that aggregate stability depends, not just on clay
content, but also on clay type, with differences expressed in the CEC. Reichert
& Norton (1994) also observed that aggregate stability was positively related to
CEC for soils with 1:1 type clay minerals and oxides, and negatively related
with 2:1 clay mineralogy soils, suggesting that for 2:1 clay minerals soils,
increasing CEC may decrease aggregate stability due to increased amount of
hydration cations and degree of swelling and dispersion. On the other hand, for
these soils we did not find any relationship between CEC and SR (Table 4).
40
6 CONCLUSIONS
Soil samples from Brazilian eucalyptus cultivation areas were
physically, chemically and mineralogically characterized and tested using
HEMC aggregate stability methods.
Soil x-ray diffraction patterns showed that soils have practically the
same mineralogical composition within a region; this was likely due to minor
differential pedogenetic development and the same parent material.
Independent of soil classes studied, kaolinite was the predominant
crystalline mineral, which resulted in soil with a low natural fertility.
Soils showed a large variation in texture; with a weak relationship with
aggregate stability.
For soils with 1:1 type clay mineralogy, soils were well aggregated;
being such aggregation not well correlated with clay content, soil organic matter,
or Feo/Fed.
Soil external properties such as affected by management practices and
long-term of eucalyptus cultivation had probably caused the high stability ratio
found.
41
7 REFERENCES
AJAYI, A. B.; DIAS JUNIOR, M. S.; CURI, N.; GONTIJO, I.; ARAÚJO
JÚNIOR, C. F.; VASCONCELOS JÚNIOR, A. I. Relation of strength and
mineralogical attributes in brazilian latosols. Soil and Tillage Research,
Amsterdam, v. 102, n. 1, p. 14-18, Jan. 2009.
ASSOCIAÇÃO BRASILEIRA DE PRODUTORES DE FLORESTA
PLANTADA. ABRAF statistical yearbook: base year 2008. Brasilia, 2009.
120 p.
BLAKE, G. R.; HARTGE, K. H. Bulk density. In: KLUTE, A. (Ed). Methods
of soil analysis. 2. ed. Madison: American Society of Agronomy. 1986a. p. 363-
375.
BLAKE, G. R.; HARTGE, K. H. Particle density. In: KLUTE, A. (Ed.).
Methods of soil analysis. 2. ed. Madison: American Society of Agronomy.
1986b. p. 377-382.
BRASIL. Ministério da Agricultura. Escritório de Pesquisas e Experimentação.
Equipe de Pedologia e Fertilidade do Solo. Levantamento exploratório dos
solos da região sob influência da Cia. Vale do Rio Doce. Rio de Janeiro, 1970.
148 p. (Boletim Técnico, 13).
CELULOSE NIPO BRASILEIRA. Levantamento semidetalhado dos solos
das regiões do Rio Doce, Cocais, Sabinópolis e Virginópolis. Ipatinga, 2001.
101 p.
CHILDS, E. C. The use of soil moisture characteristics in soil studies. Soil
Science, Baltimore, v. 50, n. 4, p. 239-252, Apr. 1940.
COLLINS-GEORGE, N.; FIGUEROA, B. S. The use of high energy moisture
characteristic to asses soil stability. Australian Journal of Soil Research,
Melbourne, v. 22, n. 3, p. 349-356, May/June 1984.
DANIELSON, R. E.; SUTHERLAND, P. L. Porosity. In: KLUTE, A. (Ed.).
Methods of soil analysis: part 1, physical and mineralogical methods. Madison:
American Society of Agronomy, 1986. p. 443-461.
42
DE-CAMPOS, A. B.; MAMEDOV, A. I.; HUANG, C. Short-term reducing
condition decrease soil aggregation. Soil Science Society of America Journal,
Madison, v. 73, n. 2, p. 550-559, Mar./Apr. 2009.
DENEF, K.; SIX, J. Clay mineralogy determines the importance of biological
versus abiotic processes for macroaggregate formation and stabilization.
European Journal of Soil Science, Oxford, v. 56, n. 4, p. 469-479, Aug. 2005.
DUARTE, M. N.; CURI, N.; PÉREZ, D. V.; KÄMPF, N.; CLAESSEN, M. E.
C. Mineralogia, química e micromorfologia de solos de uma microbacia nos
Tabuleiros Costeiros do Espírito Santo. Pesquisa Agropecuária Brasileira,
Brasília, v. 35, n. 6, p. 1237-1250, jun. 2000.
EMPRESA BRASILEIRA DE PESQUISAS AGROPECUÁRIA. Manual de
métodos de análise de solo. 2. ed. Rio de Janeiro: Embrapa/CNPS 1997. 212 p.
(Documentos, 1).
EMPRESA BRASILEIRA DE PESQUISAS AGROPECUÁRIA. Sistema
Brasileiro de Classificação de Solos. 2.ed. Rio de Janeiro: Embrapa Solos,
2006. 306 p.
FERREIRA, M. M.; FERNANDES, B.; CURI, N. Influência da mineralogia da
fração argila nas propriedades físicas de latossolos da região suldeste do Brasil.
Revista Brasileira de Ciência do Solo, Campinas, v. 23, n. 3, p. 515-524, 1999.
GEE, G. W.; OR, D. Particle-size analysis: hydrometer method. In: DANE J.H.,
TOPP, G.C. (Ed.). Methods of soil analysis: part 4, physical methods. Madison:
American Society of Agronomy, 2002. p. 278-283. (Soil Science Society of
America Book Series, 5).
KÄMPF, N.; CURI, N. Argilominerais em solos brasileiros. In: CURI, N.;
MARQUES, J. J.; GUILHERME, L. R. G.; LIMA, J. M.; LOPES, A. S.;
ALVAREZ V., V. H. (Ed.). Tópicos em ciência do solo. Viçosa, MG:
Sociedade Brasileira de Ciência do Solo. 2003. p. 1-54.
KÄMPF, N.; CURI, N. Óxidos de ferro: indicadores de ambientes pedogênicos e
geoquímicos. In: NOVAIS, R. F.; ALVAREZ V., V. H.; SCHAEFER, C. E.
(Ed.). Tópicos em ciência do solo. Viçosa, MG: Sociedade Brasileira de
Ciência do Solo. 2000. p. 107-138.
43
KEMPER, W. D.; ROSENAU, R. C. Aggregate stability and size distribution.
In: KLUTE, A. (Ed.). Methods of soil analysis: part 1, physical and
mineralogical methods. Madison: American Society of Agronomy, 1986. p. 441-
442.
LADO, M.; BEN-HUR, M.; SHAINBERG, I. Soil wetting and texture effects on
aggregate stability, seal formation, and erosion. Soil Science Society of
America Journal, Madisson, v. 68, n. 4, p. 1992-1999, July 2004.
LE BISSONNAIS, Y. Aggregate stability and assessment of soil crustability and
erodibility: I. theory and methodology. European Journal of Soil Science,
Oxford, v. 47, n. 4, p. 425-437, Apr. 1996.
LEVY, G. J.; MAMEDOV, A. I. High-energy-moisture-characteristic aggregate
stability as a predictor for seal formation. Soil Science Society of America
Journal, Madisson, v. 66, n. 5, p. 603-1609, Sept. 2002.
LEVY, G. J.; MAMEDOV, A. I.; GOLDSTEIN, D. Sodicity and water quality
effects on slaking of aggregates from semi-arid soils. Soil Science, Baltimore, v.
168, n. 8, p. 552-562, Aug. 2003.
LEVY, G. J.; MILLER, W. P. Aggregate stability of some Southeastern U.S.
soils.Soil Science Society of America Journal, Madisson, v. 61, n. 6, p. 1176-
1182, Nov. 1997.
LIMA, J. M.; ANDERSON, S. J. Aggregation and aggregate size effects on
extractable iron and aluminum in two Hapludoxs. Soil Science Society of
America Journal, Madisson, v. 61, n. 3, p. 965-970, May 1997.
MAMEDOV, A. I.; BECKMANN, S.; HUANG, C.; LEVY, G. J. Aggregate
stability as affected by polyacrylamide molecular weight, soil texture, and water
quality. Soil Science Society of America Journal, Madisson, v. 71, n. 6, p.
1909-1918, Nov. 2007.
MAMEDOV, A. I.; HUANG, C.; LEVY, G. J. Antecedent moisture content and
aging duration effects on seal formation and erosion in smectitic soils. Soil
Science Society America Journal, Madison, v. 70, n. 3, p. 832-843, May 2006.
MARTINS, S. G. Erosão hídrica em povoamentos de eucalipto sobre solos
coesos nos Tabuleiros Costeiros, ES. 2005. 106 p. Tese (Doutorado em Solos e
Nutrição de Plantas) – Universidade Federal de Lavras, Lavras.
44
MEHRA, O. P.; JACKSON, M. L. Iron oxide removal from soils and clays by
dithionite-citrate-bicarbonate system buffered with sodium bicarbonate. Clays
and Clay Mineralogy, New York, v. 7, n.1, p. 317-327, 1960.
MEURER, E. J. Fundamentos de química do solo. 2. ed. Porto Alegre:
Genesis, 2004. 290 p.
MUGGLER, C. C.; VAN GRIETHUYSEN, C.; BUURMAN, P.; PAPE, Th.
Aggregation, organic matter, and iron oxide morphology in Oxisols from Minas
Gerais, Brazil. Soil Science, Baltimore, v. 164, n. 10, p. 759-770, Oct. 1999.
NORTON, L. D.; MAMEDOV, A. I.; HUANG, C.; LEVY, G. L. Soil aggregate
stability as affected by long-term tillage and clay mineralogy. Advances in
GeoEcology, Amsterdam, v. 39, p. 422-429, Aug. 2006.
OLIVEIRA, A. H. Erosão hídrica em florestas de eucalipto na região sudeste
do Rio Grande do Sul. 2008. 53 p. Dissertação (Mestrado em Solos e Nutrição
de Plantas) – Universidade Federal de Lavras, Lavras.
OLIVEIRA, F. P. Erosão hídrica em áreas florestais no Vale do Rio Doce,
região centro-leste do estado de Minas Gerais. 2006. 105 p. Dissertação
(Mestrado em Solos e Nutrição de Plantas) – Universidade Federal de Lavras,
Lavras.
PIERSON, F. B.; MULLA, D. J. An improved method for measuring aggregate
stability of a weakly aggregate loessial soil. Soil Science Society of America
Journal, Madisson, v. 53, n. 6, p. 1825-1831, Nov. 1989.
PINHEIRO-DICK, D.; SCHWERTMANN, U. Microaggregates from Oxisols
and Inceptisols: dispersion through selective dissolutions and physicochemical
treatments. Geoderma, Amsterdam, v. 74, n. 1/4, p. 49-63, Sept. 1996.
RAMGRAB, G. E. Programa levantamentos geológicos básicos do Brasil:
Porto Alegre, Estado do Rio Grande do Sul, Escala 1:250.000. Brasília: CPRM.
1997. (Folhas SH, 22-Y-B).
REICHERT, J. M.; NORTON, L. D. Aggregate stability and rain-impacted sheet
erosion of air-dried and prewetted clayey surface soils under intense rain. Soil
Science, Baltimore, v. 158, n. 3, p. 159-169, Sept. 1994.
45
RUIZ-VERA, V. R.; WU, L. Influence of sodicity, clay mineralogy, prewetting
rate, and their interaction on aggregate stability. Soil Science Society of
America Journal, Madison, v. 70, n. 6, p. 1825-1833, Nov. 2006.
SCHWERTMANN, U. Differenzierung der eisenoxyde des bodens durch
extraktation mit ammoniumoxalat-Losung. Zeitschrift für Pflanzenernährung
Düngung und Bodenkunde, Berlin, v. 105, n. 3, p. 194-202, 1964.
SCOTT, N. A.; VERNON COLE, C.; ELLIOTT, E.T.; HUFFMAN, S. A. Soil
texture control on decomposition and soil organic matter dynamic. Soil Science
Society of America Journal, Madison, v. 60, n. 4, p. 1102-1109, July 1996.
SIX, J.; ELLIOTT, E. T.; PAUSTIAN, K. Soil structure and soil organic matter:
II. A normalized stability index and the effect of mineralogy. Soil Science
Society of America Journal, Madison, v. 64, n. 4, p. 1042-1049, July 2000a.
SIX, J.; PAUSTIAN, K.; ELLIOTT, E. T.; COMBRINK, C. Soil structure and
soil organic matter: I, distribution of aggregate-size classes and aggregateassociated
carbon. Soil Science Society of America Journal, Madison, v. 64, n.
2, p. 681-689, Mar. 2000b.
SOIL SURVEY STAFF. Soil Taxonomy. 2. ed. Washington: USDA, 1999. 869
p.
TARDY, Y.; NAHON, D. Geochemistry of laterites, stability of Al-goethite, Alhematite,
and Fe3+-kaolinite in bauxites and ferricretes: an approach to the
mechanism of concretion formation. American Journal of Science, Madison, v.
285, n. 10, p. 865-903, Dec. 1985.
VAN GENUCHTEN, M. Th. A closed-form equation for predicting the
hydraulic conductivity of unsaturated soils. Soil Science Society of America
Journal, Madison, v. 44, n. 5, p. 892-898, Sept. 1980.
VETTORI, L. Ki e Kr de terra fina e de argila. In: CONGRESSO BRASILEIRO
DE CIÊNCIA DO SOLO, 7., 1959, Piracicaba. Anais… Piracicaba: SBCS,
1959. p. 35.
WALKLEY, A.; BLACK, I. A. An examination of the Degtjareff method for
determining soil organic matter and a proposed modification of the chromic acid
titration method. Soil Science, Baltimore, v. 37, n. 1, p. 29-38, Jan. 1934.
46