SlideShare a Scribd company logo
SOIL QUALITY PARAMETERS OF A XANTHIC FERRALSOL IN THE AMAZON BASIN
Wenceslau Geraldes Teixeira (1) ;Goetz Schroth (2).; Maria do Rosário Lobato Rodrigues (1),
(1) Embrapa Amazônia Ocidental, CP 319, 69011-970 Manaus – AM; lau@cpaa.embrapa.br
(2) INPA – Biological Dynamics of Forest Project, C.P. 478 – 69011-970- Manaus
Decline in the productivity of tropical soils under continuous cultivation, even with supplementary
fertilisation, is well documented. It confirms that productivity of tropical land use agricultural systems
is not only dependent on the stock of nutrients in the soil or the availability of commercial fertilisers,
but it is also dependent on the maintenance of the soil structure. A better understanding of the processes
affecting the soil following forest conversion to agriculture systems is very important to define which
land use systems may maintain the agriculture potential of the clayey Ferralsols in the central Amazon.
The present study was conducted to investigate alterations in soil properties as affected by plant-soil
interaction and specific soil management. Three land use systems were investigated. They were i) a
conventional monoculture of peach palm (Bactris gasipaes); ii) a monoculture of cupuaçu (Theobroma
grandiflorum) and iii) a complex agroforestry association with peach palm, cupuaçu, Brazil nut
(Bertholletia excelsa) and annatto (Bixa orellana). The soil was covered by Pueraria phaseoloides in
all systems except the peach palm monoculture. Adjacent areas of primary and secondary forest were
investigated for comparison. The study was carried out at the experimental station of Embrapa–
Amazônia Ocidental in Manaus, Brazil. The soil is a clayey Xanthic Ferralsol. The climate is classified
as Aw (Köppen classification). Disturbed soil samples were collected at ≈ 40 cm far from the trunks.
The conventional sieve-pipette sedimentation method was used (EMBRAPA, 1997). Additionally,
water dispersible clay was measured by repeating the above described texture analysis, except that the
chemical dispersion agent was excluded then indexes of flocculation (IF) were calculated. The soil pH
and the cations calcium (Ca2+), magnesium (Mg2+) and aluminium (Al3+) were extracted by N KCl and
determined by atomic absorption spectrometry (EMBRAPA, 1997).
RESULTS
The high flocculation indexes indicate that most clay particles in field conditions are flocculated (Table
1). As a consequence of this flocculation and the structured aggregates present in the Ferralsols, these
soils behave like sand in terms of water infiltration near saturated conditions but behave like clay soils
at higher tensions with respect to infiltration rates and water holding capacity.
Table 1 does not show significant differences for IF between treatments, however, a highly significant
difference between the blocks was found (Figure 1). In the blocks C and B the effect of liming and
previous fertilisation promoted clay particle deflocculation near the soil surface. A similar effect on
clay particle deflocculation by liming was reported by Roth and Pavan (1991).
Table 1 Exploratory analysis indexes of flocculation [%] data set evaluated on different land use system in a
clayey Ferralsol in the Central Amazon – Brazil.
Land Use System
Specie
mean
SE of mean
Median
Maximum
Minimum
Agroforestry
Cupuaçu
73.60a
2.49
72.60
69.87
78.33
Agroforestry
Annatto
74.97a
7.35
76.23
61.66
87.01
Agroforestry
Brazil nut
75.41a
4.85
78.37
65.93
81.93
Agroforestry
Peach palm – F
75.72a
2.69
74.96
71.50
80.71
Agroforestry
Peach palm – P
69.80a
7.39
75.33
55.17
78.90
Agroforestry
Pueraria
75.46a
4.71
79.82
66.04
80.52
Monoculture
Cupuaçu
72.13a
4.02
72.49
64.99
78.91
Monoculture
Grasses and pueraria
70.11a
5.96
64.64
63.68
82.01
Monoculture
Peach palm – F(m)
73.11a
8.22
76.07
57.63
85.63
Monoculture
Peach palm – F(mb)
74.68a
1.68
75.65
71.41
76.97
Monoculture
Peach palm –P(m)
73.98a
1.65
74.68
70.84
76.41
Monoculture
Peach palm –P(mb)
68.32a
4.10
70.39
60.41
74.16
Fallow
Vismia
75.23a
6.87
80.12
61.66
83.91
Average
73.27
1.26
74.96
55.17
87.01
m = monoculture; b = between the palms; F = Peach palm for fruits production; P = Peach palm for palm heart production.
Means followed by the same letters within the column, do not differ by Tukey’s test (α < 0.05).

Deflocculation after liming is explained by substitution of Al3+ by Ca2+ and Mg2+ on the
exchange complex. The ions of Al3+ had a greater flocculation power in the original soil conditions,
because they are tightly absorbed and compress the electrical double layer (Jury et al., 1991). In the
original conditions, i.e., when the soil is covered by primary forest, the clay particles on clayey
Ferralsols near Manaus are almost totally flocculated (Teixeira, et al., 1997). This is a consequence of
the low pH and its relations with the surface charge of the clay colloids. The experiment was limed in
November/December 1996 with 2.1 Mg ha-1 of dolomitic lime, which was broadcast in the plots. Soil
sampling was conducted on block A before the application of lime, whereas blocks B and C were
sampled in January 1997. Figure 1 shows higher values of Ca2+, Mg2+ and pH and reduced levels of
Al3+ for block C. It was probably caused by a more intense use of lime and fertiliser in the previous
experiments in those areas. The reduced levels may present near bacabas and matá-matás in the
primary forest (Table 2) represent the original levels of these parameters. In the secondary forest the
plots were not limed or fertilised during the present experiment, the levels of Ca2+ and Mg2+ where not
so high (Table 2), but confirms an anterior different use of the site. This fact is reflected in a highly
significant effect of blocks for the chemical parameters (Figure 1) Variability between blocks clearly
does not affect differences between treatment means, since each treatment appears the same number of
times in every block. Nevertheless, significant treatment effects were found for pH, Al3+ and Ca2+. An
important implication of the results is the fact that certain management practices, which improve soil
fertility, may be detrimental to soil structure (i.e., liming reduced intra-aggregate bonds by eliminating
most positive charges). Fortunately, the origin of the inter-aggregate bonding is non-electrostatic in
these Ferralsols, but are principally due to the activity of roots and earthworms (Chauvel, 1982). This
fact tends to reduce the detrimental consequences of such changes in the functionality of the soil
structure. Therefore, the most visible effects of the collapse of the soil structure, which are normally an
expressive reduction of bulk density, could not be observed yet. Conversely, a increase in pH and
higher concentration of mineral nutrients in the soil may result in more intense biological activity and
the formation of polysaccharides, which promote aggregation and as a probable consequence, the
opposite effect would be observed some time later, showing that the deflocculation of clay in the
Ferralsols following liming was a temporary phenomenon. Further investigations are necessary to
confirm or refute the hypothesis of a better aggregation on a long-term basis from the increase of pH
and reduction of Al3+.
CONCLUSIONS
While laboratory measurements of particle size distribution using the classical method with chemical
agent of dispersion provided no different results, the flocculation indexes of clay particles indicated
changes in the natural aggregation of the clay particles correlated with the reduction of Al level and an
increase of the levels of Ca, Mg and pH. The monitoring of chemical parameter and the index of
flocculation, which are cheaply and easily evaluated, can be used as indicators of stability of the soil
structure of clayey Ferralsols. It is a crucial factor for the sustainability of land use systems on the
strongly aggregate clayey Ferralsols that their structure remains stable.
REFERENCES
CHAUVEL A. Os Latossolos amarelos, álicos, argilosos dentro dos ecossistemas das bacias experimentais do INPA e da
região vizinha. Acta Amazonica. 12: 47-60, 1982.
EMBRAPA. Manual de métodos de análise de solo. 2.ed. Rio de Janeiro, Centro nacional de pesquisa de solos, 1997. 212p.
JURY W A.; GARDNER W R. and GARDNER W H. Soil physics. 5.ed. New York, John Wiley & Sons, 1991. 328p.
TEIXEIRA W G.; PEREIRA E G.; CRUZ L A. and BUENO N. Influência do uso nas característica fisico quimicas de um
latossolo amarelo, textura muito argilosa, Manaus - AM. In: Congresso latino americano de ciência do solo, 13.,
1997. Sociedade Brasileira de Ciencia do Solo, Campinas, 1997. p.1-4.
TEIXEIRA W G. Land use effects on soil physical and hydraulic properties of a clayey Ferralsol in the Central Amazon.
Bayreuther Bodenkunde Berichte. Bayreuth. 2001. Band 72. 255p
Table 2 Soil chemical characteristics evaluated on different land use systems in a clayey Ferralsol - Brazil.
Land Use System
Specie
ph
Ca2+§
Mg2§
Al3+
-3
_______cmolc dm _______
Agroforestry
Cupuaçu
4.50 c
1.41 ab
1.10 a 0.99 abc
Agroforestry
Annatto
3.97 abc
0.46 a
0.33 a 1.75 bc
Agroforestry
Brazil nut
4.33 abc
2.26 ab
0.84 a 0.68 ab
Agroforestry
Peach palm – F
4.20 abc
1.49 ab
0.93 a 0.73 ab
Agroforestry
Peach palm – P
4.13 abc
0.97 ab
0.55 a 1.06 abc
Agroforestry
Pueraria
4.17 abc
1.44 ab
1.25 a 1.17 abc
Monoculture
Cupuaçu
4.40 bc
1.61 ab
1.07 a
0.53 a
Monoculture
Grasses and pueraria 3.80 abc
0.50 ab
0.30 a 1.63 abc
Monoculture
Peach palm – F(m)
4.17 abc
0.90 ab
0.68 a 0.95 abc
Monoculture
Peach palm – F(mb)
4.27 abc
0.67 ab
0.41 a 1.36 abc
Monoculture
Peach palm –P(m)
4.07 abc
1.69 ab
1.20 a 0.74 ab
Monoculture
Peach palm –P(mb)
4.57 c
1.51 ab
1.07 a 0.68 ab
Fallow
Vismia
3.77 a
0.19 b
0.18 a 1.95 c
Primary forest
Escheweilera sp
3.86
0.05
0.08
1.61
Primary forest
Oenocarpus bacaba
3.79
0.04
0.08
1.85
m = monoculture; b = between the palms; F = Peach palm for fruits production; P = Peach palm for palm heart
production.§ - Original means (statistical analysis was carried out with transformed data). Means followed by the same
letters within the column, do not differ by Tukey’s test (α < 0.05). Primary forest data were not include in the
statistical analysis..

Figure 1 Graphical means of a) indexes of flocculation [%], b) concentration of aluminium [cmolc dm-3] c) concentration of
calcium [cmolc dm-3] and d) concentration of magnesium [cmolc dm-3] evaluate in a clayey Ferralsol in the central
Amazon. Error bars represent the standard error of mean.
87

2 .0

79

1 .5
A l3+

IF 7 1

1 .0

63

0 .5

55

A

B
B lo c k

0 .0

C

A

B
B lo c k

C

2

2 .0

1 .5
Ca

1

2+

M g 2+

1 .0

0
0 .5

0 .0

A

B
B lo c k

C

-1

A

B
B lo ck

C

More Related Content

PDF
Soil carbon storage in Mediterranean forest stands: implications in the resto...
PDF
Impact of Agricultural Management on Quality of Soil, Carbon Storage and Carb...
PDF
Soil - Plant Nutrient Correlation Analysis of Maize Varieties at the Guinea S...
PDF
A comparative study of the physical and chemical properties of soils under di...
PDF
55044 311170-2-pb
PDF
Malting Sludges as Soil Amendment
PPT
Poster xebsh-carvalho atal versao final beata-30set
PPT
Effects of integrated water and nutrient management technologies on crop and ...
Soil carbon storage in Mediterranean forest stands: implications in the resto...
Impact of Agricultural Management on Quality of Soil, Carbon Storage and Carb...
Soil - Plant Nutrient Correlation Analysis of Maize Varieties at the Guinea S...
A comparative study of the physical and chemical properties of soils under di...
55044 311170-2-pb
Malting Sludges as Soil Amendment
Poster xebsh-carvalho atal versao final beata-30set
Effects of integrated water and nutrient management technologies on crop and ...

What's hot (20)

PDF
Discharge–calcium concentration relationships in streams
PPTX
A framework for assessing and reporting resilience of native vegetation
PDF
Barrera_SMBposter_ASA2012
PDF
Peralta et al., 2013. Delineation of management zones with electroconductivity
PPT
Effect of organic and inorganic amendments for enhancing health of ravinous s...
PDF
Diversity and ecology of macrofauna in land use mosaics embu and taita distri...
PDF
Aurora poster for ASSW 2015
PDF
Effect of applied phosphorus on the availability of micronutrients in alkalin...
PDF
Utilization of Marginal Soils with Application of Phosphorus and Ethephon for...
PDF
PDF
Soum rangeland management planning guideline
PDF
Vermicomposting ecological way to recycle organic wastes
PDF
Soil properties and dune heath reestablishment
PDF
Baseline physiochemical properties of soil in selected ca sites of the lake c...
PDF
Improving Fruit Quality and Nutritional Value of Deglet Nour dates subjected ...
PPTX
Using VAST to inform the development regional environmental accounts
PPT
Peatnet - 2nd International Symposium Peatlands in the Global Carbon Cycle (2...
PDF
Carbon sequestration through the use of biosolids in soils of the Pampas reg...
PDF
11.[6 16]characterization of soils at angacha district in southern ethiopia
Discharge–calcium concentration relationships in streams
A framework for assessing and reporting resilience of native vegetation
Barrera_SMBposter_ASA2012
Peralta et al., 2013. Delineation of management zones with electroconductivity
Effect of organic and inorganic amendments for enhancing health of ravinous s...
Diversity and ecology of macrofauna in land use mosaics embu and taita distri...
Aurora poster for ASSW 2015
Effect of applied phosphorus on the availability of micronutrients in alkalin...
Utilization of Marginal Soils with Application of Phosphorus and Ethephon for...
Soum rangeland management planning guideline
Vermicomposting ecological way to recycle organic wastes
Soil properties and dune heath reestablishment
Baseline physiochemical properties of soil in selected ca sites of the lake c...
Improving Fruit Quality and Nutritional Value of Deglet Nour dates subjected ...
Using VAST to inform the development regional environmental accounts
Peatnet - 2nd International Symposium Peatlands in the Global Carbon Cycle (2...
Carbon sequestration through the use of biosolids in soils of the Pampas reg...
11.[6 16]characterization of soils at angacha district in southern ethiopia
Ad

Viewers also liked (14)

DOCX
стрінками доброти пізнавальна конфенренція за творамив. о. сухомлинського
DOC
день перемоги
PPTX
презентація
PPTX
буква щ
PPSX
Self introduction
PPTX
LO QUE SUELE SUCEDER EN FIN DE AÑO
PDF
Doe a case study
DOC
чорнобиль
PPTX
division
PPTX
LO QUE SUELE SUCEDER EN FIN DE AÑO
PDF
The cyber resilient enterprise
DOCX
буква щ
DOC
ข้อสอบปลายภาค ม.2 ภาคเรียนที่ 1. 2555(ร.ร.ธัญรัตน์)ฉบับสมบูรณ์
PPTX
The audio lingual method
стрінками доброти пізнавальна конфенренція за творамив. о. сухомлинського
день перемоги
презентація
буква щ
Self introduction
LO QUE SUELE SUCEDER EN FIN DE AÑO
Doe a case study
чорнобиль
division
LO QUE SUELE SUCEDER EN FIN DE AÑO
The cyber resilient enterprise
буква щ
ข้อสอบปลายภาค ม.2 ภาคเรียนที่ 1. 2555(ร.ร.ธัญรัตน์)ฉบับสมบูรณ์
The audio lingual method
Ad

Similar to Soil quality parameters in ferralsols teixeira 2002 (20)

RTF
ABSTRACT.RTF
PPT
Chemical &amp; Microbial analysis of farm &amp; forest soil
PDF
Variability in the Physico-chemical Properties of Soils of Similar Lithology ...
PDF
Variability in the Physico-chemical Properties of Soils of Similar Lithology ...
DOC
CHAPTER3.DOC
PPTX
Tree cropping system for reclamation of problem soil
PDF
Effects of Land Use on Soil Physical and Chemical Properties in Akokwa Area o...
PPTX
SUSTAINABLE SOIL FERTILITY MANAGEMENT IN BENIN: LEARNING FROM FARMERS
PDF
Properties and Potentials of Soils of Liman Katagum Bauchi State, Nigeria
PDF
Assessment of the Physicochemical and Microbial Properties of Rhizosphere Soi...
PPT
Chemical and Microbial Analysis of Soil
PDF
Soils, principles, properties and management {khan towhid osman} [97894007566...
PDF
(eBook PDF) Elements of the Nature and Properties of Soils (3rd Edition)
PPTX
Horticultural research in kogi state.pptx
DOC
CHAPTER4.DOC
PPTX
Bio-Physico- Chemical Properties of Soil
RTF
REFERENC.RTF
DOC
CHAPTER1.DOC
PPTX
SALIFU UFEDO MESHACH INTERNAL PRESENTATION.pptx
PDF
(eBook PDF) Elements of the Nature and Properties of Soils (3rd Edition)
ABSTRACT.RTF
Chemical &amp; Microbial analysis of farm &amp; forest soil
Variability in the Physico-chemical Properties of Soils of Similar Lithology ...
Variability in the Physico-chemical Properties of Soils of Similar Lithology ...
CHAPTER3.DOC
Tree cropping system for reclamation of problem soil
Effects of Land Use on Soil Physical and Chemical Properties in Akokwa Area o...
SUSTAINABLE SOIL FERTILITY MANAGEMENT IN BENIN: LEARNING FROM FARMERS
Properties and Potentials of Soils of Liman Katagum Bauchi State, Nigeria
Assessment of the Physicochemical and Microbial Properties of Rhizosphere Soi...
Chemical and Microbial Analysis of Soil
Soils, principles, properties and management {khan towhid osman} [97894007566...
(eBook PDF) Elements of the Nature and Properties of Soils (3rd Edition)
Horticultural research in kogi state.pptx
CHAPTER4.DOC
Bio-Physico- Chemical Properties of Soil
REFERENC.RTF
CHAPTER1.DOC
SALIFU UFEDO MESHACH INTERNAL PRESENTATION.pptx
(eBook PDF) Elements of the Nature and Properties of Soils (3rd Edition)

Recently uploaded (20)

PDF
Hybrid model detection and classification of lung cancer
PPTX
The various Industrial Revolutions .pptx
PDF
A comparative study of natural language inference in Swahili using monolingua...
PDF
WOOl fibre morphology and structure.pdf for textiles
PDF
ENT215_Completing-a-large-scale-migration-and-modernization-with-AWS.pdf
PPTX
Chapter 5: Probability Theory and Statistics
PDF
STKI Israel Market Study 2025 version august
PDF
DP Operators-handbook-extract for the Mautical Institute
PDF
Assigned Numbers - 2025 - Bluetooth® Document
PDF
Zenith AI: Advanced Artificial Intelligence
PPTX
O2C Customer Invoices to Receipt V15A.pptx
PPTX
Benefits of Physical activity for teenagers.pptx
PPTX
Tartificialntelligence_presentation.pptx
PDF
TrustArc Webinar - Click, Consent, Trust: Winning the Privacy Game
PDF
How ambidextrous entrepreneurial leaders react to the artificial intelligence...
PDF
A Late Bloomer's Guide to GenAI: Ethics, Bias, and Effective Prompting - Boha...
PPTX
Final SEM Unit 1 for mit wpu at pune .pptx
PPTX
Group 1 Presentation -Planning and Decision Making .pptx
PDF
Video forgery: An extensive analysis of inter-and intra-frame manipulation al...
PDF
sustainability-14-14877-v2.pddhzftheheeeee
Hybrid model detection and classification of lung cancer
The various Industrial Revolutions .pptx
A comparative study of natural language inference in Swahili using monolingua...
WOOl fibre morphology and structure.pdf for textiles
ENT215_Completing-a-large-scale-migration-and-modernization-with-AWS.pdf
Chapter 5: Probability Theory and Statistics
STKI Israel Market Study 2025 version august
DP Operators-handbook-extract for the Mautical Institute
Assigned Numbers - 2025 - Bluetooth® Document
Zenith AI: Advanced Artificial Intelligence
O2C Customer Invoices to Receipt V15A.pptx
Benefits of Physical activity for teenagers.pptx
Tartificialntelligence_presentation.pptx
TrustArc Webinar - Click, Consent, Trust: Winning the Privacy Game
How ambidextrous entrepreneurial leaders react to the artificial intelligence...
A Late Bloomer's Guide to GenAI: Ethics, Bias, and Effective Prompting - Boha...
Final SEM Unit 1 for mit wpu at pune .pptx
Group 1 Presentation -Planning and Decision Making .pptx
Video forgery: An extensive analysis of inter-and intra-frame manipulation al...
sustainability-14-14877-v2.pddhzftheheeeee

Soil quality parameters in ferralsols teixeira 2002

  • 1. SOIL QUALITY PARAMETERS OF A XANTHIC FERRALSOL IN THE AMAZON BASIN Wenceslau Geraldes Teixeira (1) ;Goetz Schroth (2).; Maria do Rosário Lobato Rodrigues (1), (1) Embrapa Amazônia Ocidental, CP 319, 69011-970 Manaus – AM; lau@cpaa.embrapa.br (2) INPA – Biological Dynamics of Forest Project, C.P. 478 – 69011-970- Manaus Decline in the productivity of tropical soils under continuous cultivation, even with supplementary fertilisation, is well documented. It confirms that productivity of tropical land use agricultural systems is not only dependent on the stock of nutrients in the soil or the availability of commercial fertilisers, but it is also dependent on the maintenance of the soil structure. A better understanding of the processes affecting the soil following forest conversion to agriculture systems is very important to define which land use systems may maintain the agriculture potential of the clayey Ferralsols in the central Amazon. The present study was conducted to investigate alterations in soil properties as affected by plant-soil interaction and specific soil management. Three land use systems were investigated. They were i) a conventional monoculture of peach palm (Bactris gasipaes); ii) a monoculture of cupuaçu (Theobroma grandiflorum) and iii) a complex agroforestry association with peach palm, cupuaçu, Brazil nut (Bertholletia excelsa) and annatto (Bixa orellana). The soil was covered by Pueraria phaseoloides in all systems except the peach palm monoculture. Adjacent areas of primary and secondary forest were investigated for comparison. The study was carried out at the experimental station of Embrapa– Amazônia Ocidental in Manaus, Brazil. The soil is a clayey Xanthic Ferralsol. The climate is classified as Aw (Köppen classification). Disturbed soil samples were collected at ≈ 40 cm far from the trunks. The conventional sieve-pipette sedimentation method was used (EMBRAPA, 1997). Additionally, water dispersible clay was measured by repeating the above described texture analysis, except that the chemical dispersion agent was excluded then indexes of flocculation (IF) were calculated. The soil pH and the cations calcium (Ca2+), magnesium (Mg2+) and aluminium (Al3+) were extracted by N KCl and determined by atomic absorption spectrometry (EMBRAPA, 1997). RESULTS The high flocculation indexes indicate that most clay particles in field conditions are flocculated (Table 1). As a consequence of this flocculation and the structured aggregates present in the Ferralsols, these soils behave like sand in terms of water infiltration near saturated conditions but behave like clay soils at higher tensions with respect to infiltration rates and water holding capacity. Table 1 does not show significant differences for IF between treatments, however, a highly significant difference between the blocks was found (Figure 1). In the blocks C and B the effect of liming and
  • 2. previous fertilisation promoted clay particle deflocculation near the soil surface. A similar effect on clay particle deflocculation by liming was reported by Roth and Pavan (1991). Table 1 Exploratory analysis indexes of flocculation [%] data set evaluated on different land use system in a clayey Ferralsol in the Central Amazon – Brazil. Land Use System Specie mean SE of mean Median Maximum Minimum Agroforestry Cupuaçu 73.60a 2.49 72.60 69.87 78.33 Agroforestry Annatto 74.97a 7.35 76.23 61.66 87.01 Agroforestry Brazil nut 75.41a 4.85 78.37 65.93 81.93 Agroforestry Peach palm – F 75.72a 2.69 74.96 71.50 80.71 Agroforestry Peach palm – P 69.80a 7.39 75.33 55.17 78.90 Agroforestry Pueraria 75.46a 4.71 79.82 66.04 80.52 Monoculture Cupuaçu 72.13a 4.02 72.49 64.99 78.91 Monoculture Grasses and pueraria 70.11a 5.96 64.64 63.68 82.01 Monoculture Peach palm – F(m) 73.11a 8.22 76.07 57.63 85.63 Monoculture Peach palm – F(mb) 74.68a 1.68 75.65 71.41 76.97 Monoculture Peach palm –P(m) 73.98a 1.65 74.68 70.84 76.41 Monoculture Peach palm –P(mb) 68.32a 4.10 70.39 60.41 74.16 Fallow Vismia 75.23a 6.87 80.12 61.66 83.91 Average 73.27 1.26 74.96 55.17 87.01 m = monoculture; b = between the palms; F = Peach palm for fruits production; P = Peach palm for palm heart production. Means followed by the same letters within the column, do not differ by Tukey’s test (α < 0.05). Deflocculation after liming is explained by substitution of Al3+ by Ca2+ and Mg2+ on the exchange complex. The ions of Al3+ had a greater flocculation power in the original soil conditions, because they are tightly absorbed and compress the electrical double layer (Jury et al., 1991). In the original conditions, i.e., when the soil is covered by primary forest, the clay particles on clayey Ferralsols near Manaus are almost totally flocculated (Teixeira, et al., 1997). This is a consequence of the low pH and its relations with the surface charge of the clay colloids. The experiment was limed in November/December 1996 with 2.1 Mg ha-1 of dolomitic lime, which was broadcast in the plots. Soil sampling was conducted on block A before the application of lime, whereas blocks B and C were sampled in January 1997. Figure 1 shows higher values of Ca2+, Mg2+ and pH and reduced levels of Al3+ for block C. It was probably caused by a more intense use of lime and fertiliser in the previous experiments in those areas. The reduced levels may present near bacabas and matá-matás in the primary forest (Table 2) represent the original levels of these parameters. In the secondary forest the plots were not limed or fertilised during the present experiment, the levels of Ca2+ and Mg2+ where not so high (Table 2), but confirms an anterior different use of the site. This fact is reflected in a highly significant effect of blocks for the chemical parameters (Figure 1) Variability between blocks clearly does not affect differences between treatment means, since each treatment appears the same number of
  • 3. times in every block. Nevertheless, significant treatment effects were found for pH, Al3+ and Ca2+. An important implication of the results is the fact that certain management practices, which improve soil fertility, may be detrimental to soil structure (i.e., liming reduced intra-aggregate bonds by eliminating most positive charges). Fortunately, the origin of the inter-aggregate bonding is non-electrostatic in these Ferralsols, but are principally due to the activity of roots and earthworms (Chauvel, 1982). This fact tends to reduce the detrimental consequences of such changes in the functionality of the soil structure. Therefore, the most visible effects of the collapse of the soil structure, which are normally an expressive reduction of bulk density, could not be observed yet. Conversely, a increase in pH and higher concentration of mineral nutrients in the soil may result in more intense biological activity and the formation of polysaccharides, which promote aggregation and as a probable consequence, the opposite effect would be observed some time later, showing that the deflocculation of clay in the Ferralsols following liming was a temporary phenomenon. Further investigations are necessary to confirm or refute the hypothesis of a better aggregation on a long-term basis from the increase of pH and reduction of Al3+. CONCLUSIONS While laboratory measurements of particle size distribution using the classical method with chemical agent of dispersion provided no different results, the flocculation indexes of clay particles indicated changes in the natural aggregation of the clay particles correlated with the reduction of Al level and an increase of the levels of Ca, Mg and pH. The monitoring of chemical parameter and the index of flocculation, which are cheaply and easily evaluated, can be used as indicators of stability of the soil structure of clayey Ferralsols. It is a crucial factor for the sustainability of land use systems on the strongly aggregate clayey Ferralsols that their structure remains stable. REFERENCES CHAUVEL A. Os Latossolos amarelos, álicos, argilosos dentro dos ecossistemas das bacias experimentais do INPA e da região vizinha. Acta Amazonica. 12: 47-60, 1982. EMBRAPA. Manual de métodos de análise de solo. 2.ed. Rio de Janeiro, Centro nacional de pesquisa de solos, 1997. 212p. JURY W A.; GARDNER W R. and GARDNER W H. Soil physics. 5.ed. New York, John Wiley & Sons, 1991. 328p. TEIXEIRA W G.; PEREIRA E G.; CRUZ L A. and BUENO N. Influência do uso nas característica fisico quimicas de um latossolo amarelo, textura muito argilosa, Manaus - AM. In: Congresso latino americano de ciência do solo, 13., 1997. Sociedade Brasileira de Ciencia do Solo, Campinas, 1997. p.1-4. TEIXEIRA W G. Land use effects on soil physical and hydraulic properties of a clayey Ferralsol in the Central Amazon. Bayreuther Bodenkunde Berichte. Bayreuth. 2001. Band 72. 255p
  • 4. Table 2 Soil chemical characteristics evaluated on different land use systems in a clayey Ferralsol - Brazil. Land Use System Specie ph Ca2+§ Mg2§ Al3+ -3 _______cmolc dm _______ Agroforestry Cupuaçu 4.50 c 1.41 ab 1.10 a 0.99 abc Agroforestry Annatto 3.97 abc 0.46 a 0.33 a 1.75 bc Agroforestry Brazil nut 4.33 abc 2.26 ab 0.84 a 0.68 ab Agroforestry Peach palm – F 4.20 abc 1.49 ab 0.93 a 0.73 ab Agroforestry Peach palm – P 4.13 abc 0.97 ab 0.55 a 1.06 abc Agroforestry Pueraria 4.17 abc 1.44 ab 1.25 a 1.17 abc Monoculture Cupuaçu 4.40 bc 1.61 ab 1.07 a 0.53 a Monoculture Grasses and pueraria 3.80 abc 0.50 ab 0.30 a 1.63 abc Monoculture Peach palm – F(m) 4.17 abc 0.90 ab 0.68 a 0.95 abc Monoculture Peach palm – F(mb) 4.27 abc 0.67 ab 0.41 a 1.36 abc Monoculture Peach palm –P(m) 4.07 abc 1.69 ab 1.20 a 0.74 ab Monoculture Peach palm –P(mb) 4.57 c 1.51 ab 1.07 a 0.68 ab Fallow Vismia 3.77 a 0.19 b 0.18 a 1.95 c Primary forest Escheweilera sp 3.86 0.05 0.08 1.61 Primary forest Oenocarpus bacaba 3.79 0.04 0.08 1.85 m = monoculture; b = between the palms; F = Peach palm for fruits production; P = Peach palm for palm heart production.§ - Original means (statistical analysis was carried out with transformed data). Means followed by the same letters within the column, do not differ by Tukey’s test (α < 0.05). Primary forest data were not include in the statistical analysis.. Figure 1 Graphical means of a) indexes of flocculation [%], b) concentration of aluminium [cmolc dm-3] c) concentration of calcium [cmolc dm-3] and d) concentration of magnesium [cmolc dm-3] evaluate in a clayey Ferralsol in the central Amazon. Error bars represent the standard error of mean. 87 2 .0 79 1 .5 A l3+ IF 7 1 1 .0 63 0 .5 55 A B B lo c k 0 .0 C A B B lo c k C 2 2 .0 1 .5 Ca 1 2+ M g 2+ 1 .0 0 0 .5 0 .0 A B B lo c k C -1 A B B lo ck C