Hedinaldo Narciso Lima

Pedogenesis and pre-Colombian land use of “Terra Preta Anthrosols” (“Indian black earth”) of Western Amazonia

Abstract The “Terra Preta de Indio” (Indian black earth) or Terra Preta of Western Amazonia is a thick, dark-coloured, anthropic epipedon, usually rich in nutrients. It occurs mostly at the fringes of the Terra Firme, along the Amazon river banks, overlying deep strongly weathered soils. We studied selected chemical, physical and mineralogical properties of seven soils, ranging from the Tertiary Plateau down to the Amazon river floodplain in the Iranduba district, near Manaus, Amazonas, Brazil. Three Terra Preta soils were classified as anthropogenic (Anthropic Xanthic Kandiudult, Anthropic Xanthic Kandiudox and Anthropic Dystropepts). Chemical, mineralogical and micropedological attributes, such as high total and available P and mica flakes in pottery remains found in the Terra Preta, indicate that the origin of soil materials of these anthrosols is closely associated with neighbouring floodplain (varzea) soils and sediments. Amazon floodplain soils were the source of soil material for pottery, since 2:1 clay minerals are not found in the Tertiary Plateau (Terra Firme) sediments. Total and available P contents of Terra Preta are associated with microfragments of bone apatite with high P and Ca values. In the anthrosols under cultivation, these values are less, with increasing Al release suggesting acidification and losses of nutrients. Large amounts of Mn and Zn occur in the anthrosols and in high-fertility floodplain soils. It is unlikely that well-drained Tertiary Plateau (Terra Firme) area far away from lowland Amazon floodplain soils could develop high-fertility Terra Preta on the top of nutrient-poor Oxisols (Latosols). The suggested model of Terra Preta formation between the Tertiary Plateau and nutrient-rich Amazon floodplain does not extend to other nutrient-poor, smaller, floodplains draining the deep-weathered interfluves of the Brazilian Uplands. This raises reservations about estimates of precolonial human population densities for the Amazon basin as a whole, assuming the widespread occurrence of such anthrosols farther inland.

Dinâmica da mobilização de elementos em solos da Amazônia submetidos à inundação

Significant part of Amazonia soils stays partially or completely waterlogged for varying periods of days to months, as result of widespread inundation or drainage deficiency in some areas, causing changes in chemical, physical and biological properties. In this work, we aimed to evaluate the dynamics of mobilization of Al, Ca, Fe, K, Mg, Mn, Na, Si, P in soils subjected to controlled six months inundation. Soil solution aliquots were collected periodically during the inundation period, determining all elements in solution. The inundation influenced the kinetics of elements, increasing their mobilization, notably in the first weeks. Levels of Fe in solution were higher in soils with greater amounts of amorphous Fe. In soils with low amorphous Fe and low organic matter contents, mobilization of Fe was very low. Levels of P in solution were influenced by all P forms, but Fe-P forms exerted the greatest influence on mobilized P. Levels of Ca, Mg, K and Na in solution were directly influenced by their exchangeable levels, as well by the Mn and Fe kinetics.

Adubação nitrogenada na produção de mudas de mogno (Swietenia macrophylla King)

Studies on silvicultural aspects of native forest species of the Amazon Rainforest are scarce, mainly those that seek to establish cultivation techniques for production of seedlings. The current work had the objective of evaluating the effects of growing levels of N in the development of mahogany seedlings. The treatments were seven growing doses that were equivalent to the application of: 0; 20; 40; 80; 100 and 120 g N ton-1 of the substratum. The source of N was urea. The experimental design was randomized blocks with eight repetitions. Evaluations were accomplished after 90 days of transplanting where it was observed answers to the growing doses of N for the diameter of stem, dry matter of the leaves and for total content of N, P, K, Ca and Mg of the leaves. The recommendation of nitrogen fertilization for the production of mahogany seedlings is of 57,5 g N ton-1 of the substratum as a first approach.

Doses crescentes de corretivo na formação de mudas de mogno (Swietenia macrophylla King)

Seedling production is one of the more important phases on the cultivation of trees, with this phase being essential for their appropriate development. The study had the objective of evaluating the growth and the absorption of nutrients in mahogany (Swietenia macrophylla King) seedling under the effect of corrective growing doses. The experiment was carried out from September 2002 to August 2003. The treatments were, 0; 0.5; 1.0; 2.0; 2.5; 3.0 and 5.0 t/ha, of a mixture of calcium carbonate and magnesium carbonate p.a., in the 4:1 proportion. The experimental design was randomized blocks with 5 repetitions, in a total of 35 parcels, each one with 3 plants. The substratum was fertilized with equivalents doses to 200-500-300 kg.ha-1 of N, P2O5 and K2O, respectively and 15 kg.ha-1 of micronutrients FTE-Br12. The growth characteristics evaluated were height, diameter of the stem, dry biomass of the aerial part, root and total, aerial part/root relation. It was determined the moisture contents of the aerial part, root and total and as a function of the last one it was estimated the contents. The averages were compared by the test of Tukey using 5% of probability. The liming affected all the growth characteristics, except the height. The nutritional necessity followed a decreasing order of K>N>Ca>Mg>P>Fe>Mn>Zn>Cu. The dose of 0.5 t.ha-1 was more advantageous from the economic point of view and can be recommended to acid subsoil of low natural fertility to compose substratum.

Efeitos de doses crescentes de calcário em solo Latossolo Amarelo na produção de mudas de pau-de-balsa (Ochroma lagopus sw., bombacaceae)

The production of quality rafts with appropriate nutritional tenor is fundamental for plant development and for forming of root systems, which present best ability to adapt to new locations after plantation. The goal of this work was to evaluate the effect of rising heat levels in the production of silent wood rafts. The treatment was constituted by rising doses of correction and was equal to 0.0; 0.25; 0.5; 0.75; 1.0; 1.5, and 2.0 t ha-1 of lime and the experimental detail used was of blocks, repeating five times. The characteristics evaluated were: plant height; diameter, dry material of the aerial part, root relation/aerial part, content of macronutrients in the plants (N, P, K, Ca, Mg and S). The results demonstrate that the practice of liming as a soil correction factor used in the soil substrate improved all the growth characteristics evaluated in seedling production of pau-debalsa (Ochroma lagopus sw., bombacaceae). The soil correction positively influenced the absorption of Ca, Mg, and S, on the other hand, there weren’t any statistically significant effects for absorption of N, P, and K resented.

Caracterização química e mineralogia de solos antrópicos (terras pretas de índio) na amazônia central

Na Amazonia brasileira e comum a ocorrencia de sitios arqueologicos. Frequentemente, observa-se que as acoes humanas nesses sitios promoveram modificacoes significativas em muitas das caracteristicas fisicas, morfologicas e quimicas dos solos desses ambientes, tornando-os muito diferentes dos solos adjacentes, especialmente nas areas de terra firme da regiao. Embora muitos estudos tenham sido conduzidos visando compreender a magnitude dessas modificacoes e seus reflexos na genese dos solos influenciados, muitas questoes precisam ser mais bem compreendidas, sobretudo as relacionadas com a mineralogia desses solos. Este estudo teve como objetivo avaliar as caracteristicas quimicas, a composicao mineralogica das fracoes argila e areia e o grau de pedogenese de cinco perfis de solos com horizonte A antropico (Au), em ambientes de terra firme e varzea, localizados na Bacia Sedimentar do Amazonas, entre Coari e Manaus-AM. Amostras de solos foram coletadas, preparadas e submetidas as analises quimicas de rotina e caracterizadas quanto aos teores de carbono oxidavel e aos teores de Si, Fe, Al e P; adicionalmente, efetuou-se a identificacao dos minerais presentes nas fracoes argila e areia, por meio de difratometria de raios X. Os resultados mostraram que as modificacoes promovidas pela atividade humana levaram a melhoria da fertilidade do solo, resultando em solos com acidez moderada, elevados teores de Ca2+ e de P disponiveis e baixos teores de Al3+ trocavel. Esses resultados tambem revelaram teores muito elevados de P-total nos horizontes antropicos, variando entre 1.630 e 8.840 mg kg-1 de P2O5. A mineralogia da fracao argila dos solos antropicos de terra firme revelou dominância de caulinita, alem da ocorrencia de gibbsita, de goethita e de oxidos de titânio (anatasio). O perfil de varzea, alem de caulinita e goethita, apresentou tambem minerais do tipo 2:1 na fracao argila. A mineralogia da fracao areia dos solos estudados revelou dominância de quartzo, independentemente do ambiente. A fracao magnetica e composta por maghemita e hematita. Constatou-se, portanto, significativa riqueza quimica nos horizontes antropicos, bem como diferencas na composicao mineralogica desses horizontes.

The use of micromorphology for the study of the formation and properties of Amazonian Dark Earths

A blood sampling device includes an expansible, flexible container which, when unfilled, lies flat with its opposed sides together. The container is connected to a support having a passage for connecting the container with a needle cannula. A manually operable valve is disposed between the passage and the container. A gas vent communicates with the passage and has a hydrophobic filter for allowing air in the needle and passage to escape without entering the collection chamber of the container. The container has an isolation chamber at the proximal end for isolating air or air bubbles that might enter the collection chamber as a result of error in sampling technique. By hand manipulation of the container, such air bubbles can be moved from the collection chamber into the isolation chamber to isolate the air bubbles and prevent further absorption of oxygen from such air bubbles into the blood sample in the collection chamber. A closure cap is provided which substantially avoids the introduction of air into a filled container when employed to close the container.

Caracterização e classificação de gleissolos da várzea do rio Solimões (Manacapuru e Iranduba), Amazonas, Brasil

The floodplains of the Solimoes River are areas periodically flooded with predominance of Gleisols,where have lived a large number of small farmers of the region. The purpose of this study was to characterize and classify five profiles of Gleysoils distributed in three floodplain areas of the Middle Amazon basin, located in the municipalities of Manacapuru and Iranduba. After the morphological description, the soil horizons were sampled to perform physical, chemical and mineralogical analyses. Similarly, significant gleization was observed in all profiles of the soil matrix, with gray to gray-green color in the surface, and light to dark gray in the subsurface horizons, denoting iron reduction. The highest levels of the sand fraction in the subsurface horizons indicated the presence of different layers of fluvial deposition, while the high silt contents evidenced the nature of recent sediments and the low degree of pedogenetic development of these soils. The predominant soil cations were Ca2+and Mg2+, with a percentage of exchangeable sodium (ESP), varying from 0.70 to 2.09. The organic carbon contents were lower than 80 g kg-1, indicating recently deposited mineral sediments. The mineralogical composition of the clay fraction showed a significant presence of 2:1 clay minerals, but little variability among profiles. These results are reflected in high sum of bases and base saturation, characterizing eutrophic soils with high clay activity.

Chemical properties and mineralogy of soils with plinthite and petroplinthite in Iranduba (AM), Brazil

Large areas of Plinthosols with ferruginous materials such as plinthite and/or petroplinthite are fairly common in the Brazilian Amazon basin. This work was carried out to investigate the chemical behavior, mineralogical composition and weathering stage of four representative soil profiles with plinthite and petroplinthite, in Iranduba, AM (Central Amazon). Three well-drained soil profiles at high elevations were studied (P1, Plinthic Vetic Ferralsol; P2 and P3, Vetic Endopetric Plinthosol) and a contrasting poorly drained soil (P4 Haplic Plinthosol), located at low elevation. After profile descriptions, soil samples were collected from each horizon, air-dried, sieved (2 mm), and analyzed for particle-size distribution, pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+, and Na+), as well as available P and total organic carbon (TOC) content. The minerals present in the clay and sand fractions, as well as in the ferruginous materials were identified by X-ray Diffraction (XRD). The weathering stage of these soils was assessed by means of Ki and Kr indexes, and the amounts of free and amorphous Fe and Al oxides by using dithionite citrate bicarbonate (DBC) and ammonium oxalate dissolution procedures, respectively. The results showed that all soils were extremely unfertile, with pH levels ranging between strong and moderate acidity, very low sum of bases and organic matter content, and of available P. The mineralogy of the soil profiles was very similar, mainly of the well-drained soils, with predominance of kaolinite and quartz in the clay and sand fractions, respectively. In the poorly-drained P4, 2:1 clay particles were also observed. These profiles can be considered highly developed according to the Ki index, however, the Ki value of P4 was higher, indicating that this soil was less developed than the others. In summary, these profiles with plinthite and petroplinthite can be characterized as highly developed and infertile soils and are, with exception of P4, well-drained.

Efeito da calagem e da correção dos teores de Ca e Mg do solo sobre o crescimento de mudas de angelim- pedra (Dinizia excelsa Ducke)

Knowledge of nutritional requirements of the species and their answers to correcting the substratum is fundamental for the production of quality seedlings. In this work, we aimed to evaluate the effect of different limestone types and the correction of Ca and Mg deficiency on the development of angelim-pedra (Dinizia excelsa) seedlings, under glasshouse conditions. We tested three types of limestone and three types of Ca:Mg provisioning on a Yellow Oxisol (with non-corrective acidity sources): T0 & control; T1 & soil limed with dolomitic lime (3:1); T2 & soil limed with magnesium lime (9:1); T3 & soil limed with calcitic lime (15:1); T4 & a mixture of calcium and magnesium, in the 3:1 proportion; T5 & calcium and magnesium, in the 9:1 proportion; and T6 & calcium and magnesium, in the 15:1 proportion. The experimental design was of random blocks, with 5 repetitions, totaling 35 parcels with 3 seedlings each. The substratum was fertilized with doses equivalent to 100-250-150 and 15 k ha-1 of N, P2O5, K2O and S respectively, and micronutrient solution (3 mL of Chelamix L-1 of distilled water). We evaluated the height, diameter of the stem, dry biomass of the aerial part, dry biomass of the root, dry biomass of the drought, aerial part/root relation and nutrient contents of the aerial part of the plants. The limestone application affected positively the height, the diameter, the matter total biomass and the absorption of Ca of the D. excelsa seedlings (p<0,05). The application of magnesium lime with Ca:Mg 9:1 proportion showed the best results.