Search

ABSTRACT The rational exploitation of the land requires planning its agricultural use, which can be supported by the agricultural land suitability (ALS) assessment. The scheme to assess ALS proposed by Food Agricultural Organization (FAO) has been adopted in Brazil based on guiding charts for subtropical, humid tropical and semi-arid tropical climate. However, the guiding chart used for the semi-arid region has dramatically limited the ALS in drylands on which rainfed agriculture has been practiced. In this study, an adequation for the ALS assessment regarding the edaphoclimatic conditions of semi-arid region was proposed to improve the representation of agricultural areas and to allow a better planning of soil conservation practices. The ALS of the south region of Ceará State (Brazil) was assessed according to the FAO scheme and its initial adaptation to the Brazilian conditions; subsequently, this assessment was obtained by two adequations. Adequation I disregarded the limiting factor of water availability, while adequation II, besides disregarding the factor of water availability, established new limits for the classes of effective soil depth. The adequations resulted in an increase of 177.19 % in the areas with regular suitability for crops to the detriment of areas with restricted suitability for crops and areas with suitability only for pasture or grazing lands. The adequations increased the agricultural suitability in 41.26 % of the area of the mapping units, and 16.77 % of them were due to the modifications related to the effective soil depth, while the other 26.35 % were due to the changes related to water availability. The results related to water availability were equivalent to those observed through the dynamic analysis of land-use and cover associated with the rainfall, which demonstrated an increase in the areas for rainfed agriculture and a reduction in fallow and pasture areas in the years with rainfall within the climatic normality. The areas considered suitable for crop production with the adequation of the scheme may be included in soil conservation programs.

ABSTRACT Understanding organic carbon and predominant humic fractions in the soil allows contributes to soil quality management. Conventional fractionation techniques require time, excessive sampling, and high maintenance costs. In this study, predictive models for organic carbon in humic substances (HS) were evaluated using hyperspectral data as an alternative to chemical fractionation and quantification by wet digestion. Twenty-nine samples of Neossolos Flúvicos (Fluvents) - A1, and 36 samples of Cambissolos (Inceptisols) - A2 were used. The samples were also analyzed jointly, creating a third sample group - A1&A2. Untransformed spectral reflectance factors were obtained using the FieldSpec Pro FR 3 hyperspectral sensor (350–2500 nm). Pre-processing techniques were employed, including Savitzky–Golay smoothing and first- and second-order derivative analysis. After selecting variables using the Backward method, which removes spectral variables that are not statistically significant for the regression. Estimation models were built by Principal Components Regression (PCR) and Partial Least Squares Regression (PLSR). The spectral data were evaluated individually for soil classes A1 and A2, and jointly for A1&A2. The PLSR was more efficient than PCR, especially for the estimation models that used the first derivative of reflectance employing the three sample groups. For samples of A1, the best estimate was seen for humic acid (RPD = 6.09) and humin (RPD = 2.38); for A2, the best models estimated the OC in fulvic acid (RPD = 2.35) and humin (RPD = 2.51); and for the joint spectral data (A1&A2), the prediction was robust for humin only (RPD = 2.01). The most representative wavelengths were observed using the first derivative with PLSR and PCR, centred on the region between 1600 and 1800 nm. The first-derivative of reflectance calculated more-robust predictive models using PLSR than PCR. The best predictions occurred for organic carbon associated with humic acid in Neossolos Flúvicos, with fulvic acid in Cambissolos, and with humin in both soil classes.

There is a variation in the depth of subsurface horizon of Planosols in semi-arid region, which may influence the agricultural potential and affect food production. The general aim of this study was to identify potentialities and limitations of two Planosols as a function of subsurface horizon depth. The adjacent profiles P1 and P2 were studied in Pentecoste (Ceará, Brazil). Morphological, physical, and chemical analyses were done aiming at soil characterization. Soil bulk density (BD), porosity, and penetration resistance (PR) were analyzed in a completely randomized split-plot design with four replicates to compare P1 and P2 and the horizons Ap and Btf. Btf was found at 62cm depth in P1 and at 18 cm depth in P2. Indicatives of water saturation were more evident in P2. The profile P1 showed lower hardness and higher friability, as well as higher acidity in subsurface (pHH2O from 4.4 to 4.7) and higher aluminum content (1.2cmolc kg-1). Both profiles were eutrophic and showed low contents of organic carbon (1.5 to 8.5g kg-1) and phosphorus (0.9 to 3.9mg kg-1). The sodium percentage in CEC was 9.1% in P1 and 5.5% in P2. Water retention increases in Btf compared with Ap was 7.3% in P2 and 2.7% in P1. Both profiles showed increase in BD in Btf, reaching 1.7g cm-3, while PR was higher in P2 (1.5 MPa). There are potentialities and limitations common to both soil profiles, but P1 has more physical potentialities and more chemical limitations than P2.

Forest management activities influence fine root development, total soil carbon (TSC) and size of aggregates. A field experiment was carried out in Vertisols of two adjacent catchments in a seasonally dry tropical forest (SDTF) to investigate the thinning on fine-root biomass, stock of the total soil carbon and aggregate size. The catchments are located in the State of Ceará, Brazil. The control catchment of 2.1 ha has been under regenerating vegetation for 35 years (RC35), while the second catchment (1.1 ha) was subjected to thinning (TC5) in December of 2008. The analysed variables were: fine-root biomass in the 0-10, 10-20 and 20-30 cm soil layers, TSC and mean weight diameter of the soil aggregates in the 0-20, 20-40 e 40-60 cm layers. The data were submitted to Pearson correlation analysis and compared by paired t-test (P < 0.05). The 0-10 cm layer of the TC5 management stored double the average amount of fine-roots found in the RC35. Under the TC5 management, stocks of soil TSC increased by 237 and 151% in the 20-40 and 40-60 cm layers, respectively, when compared with RC35. Aggregates 2.15 times greater than those found under RC35 management were obtained in the topsoil (0-20 cm) under the TC5 management. The implementation of thinning in a Vertisol of a SDTF emerges as an alternative management to be considered in projects for sustainability in the semi-arid region, contributing to an improvement in soil structure as well as an increase in the stocks of total carbon.

ABSTRACT Hydrogels have potential as soil conditioners due to their high capacity to retain water and mitigate soil salinity. However, investigations under saline conditions are necessary because there are losses in both water absorption and salinity mitigation depending on the composition of hydrogel and ions involved in salinity. In this work, we studied a commercial hydrogel in two experiments. The first experiment was conducted in the laboratory to evaluate the absorption by the hydrogel of water with electrical conductivity (EC) of 0.5, 1.5, 3.0, and 4.5 dS m–1, promoted by NaCl. The second experiment was conducted in a greenhouse in a 2 × 4 factorial scheme (with and without hydrogel × EC of the first experiment). Although salinity reduced water absorption by hydrogel by 84 %, the polymer applied in a sandy soil under saline conditions reduced water losses by 58 %. However, hydrogel did not increase the final soil moisture (~ 0.10 g g–1). The polymer reduced Na+ concentration in leachate from 1,499 to 1,219 mg L–1 at the highest salinity level (4.5 dS m–1), but it increased Na+ soil availability by 0.1 mg kg–1 in comparison with polymer absence. Hydrogel application increased Na+ content in plants from 9 to 13 mg kg–1 at the highest salinity, while K+ content was 10 to 16 mg kg–1 lower than that observed without a polymer. Hydrogel 0.07 % (w/w) reduced maize biomass, indicating damage by monovalent ions, compromising the polymer potential under salinity.

ABSTRACT The objective of this study was to evaluate, through multivariate data analysis, which tree legume residues have the best fertilizer potential for agricultural crops in the semi-arid region of northeastern Brazil. The experiment was conducted in pots, in a randomized block design, with seven treatments and four replicates. Treatments consisted of residues of Sabiá, Jurema Preta and Gliricidia, besides two parts of the plant: leaves and leaves + branches. The pots were filled with 8.0 dm3 of soil and the residues were added in the form of green mass, corresponding to 73.0 g of dry mass per pot. Maize seeds were sown and, at 65 days after addition of the residues, soil chemical attributes, growth and nutrient contents in the plants were evaluated. The data were studied through principal component analysis, clustering analysis, canonical discriminant function analysis and means comparison test from canonical variable 1. Gliricidia residues positively influenced soil K and Mg contents, as well as height, stem diameter, number of leaves and leaf contents of P, N and Mg in maize plants. These residues showed greater dissimilarity and separation compared to the control treatment and led to statistically higher means compared to the other treatments. Jurema Preta leaves positively influenced soil Ca, N and TOC, as well as leaf contents of K and Ca and total dry mass of maize. Multivariate statistical analysis made it possible to identify distinct potentials among legume residues for use as fertilizer in maize crop, and Gliricidia is the species with highest potential.

Nas regiões semiáridas, com destaque para o nordeste brasileiro, a agropecuária praticada nos assentamentos rurais é de base familiar. Supõe-se que a adoção de práticas convencionais de uso da terra favoreça a degradação dos solos. Neste estudo objetivou-se diagnosticar as práticas de uso da terra empregadas pelos agricultores, identificando as vulnerabilidades e a viabilidade de adoção de práticas conservacionistas ainda não utilizadas. Foi aplicado questionário com 20 perguntas sobre a caracterização e as formas de uso do solo no assentamento. O questionário foi aplicado à 19 famílias, representando uma amostra de 16% do universo de 120 famílias. Os agricultores reconheceram o predomínio de solos argilosos situados em relevo plano e levemente ondulado, além da presença de solos pedregosos. Foi relatado predomínio do plantio consorciado de milho e feijão, com uso dos restos culturais para a alimentação animal. Mais de 50% das famílias informaram fazer gradagem para preparo do solo, além da realização do plantio morro abaixo. Também foi relatado o uso do fogo para preparo das áreas e a não utilização de agroquímicos. A maior parte das famílias informaram que a assistência técnica proporcionada por entidades governamentais é a mais procurada, destacando a importância de que essas entidades orientem os agricultores quanto aos aspectos de manejo e conservação do solo ainda não utilizados. Os agricultores necessitam ser orientados para aprimorar práticas conservacionistas que já vêm sendo adotadas, tais práticas conservacionistas desenvolvidas no assentamento não devem ser consideradas apenas como interesse local, pois impactam a sociedade de maneira global.

In the search for high efficiency in root studies, computational systems have been developed to analyze digital images. ImageJ and Safira are public-domain systems that may be used for image analysis of washed roots. However, differences in root properties measured using ImageJ and Safira are supposed. This study compared values of root length and surface area obtained with public-domain systems with values obtained by a reference method. Root samples were collected in a banana plantation in an area of a shallower Typic Carbonatic Haplic Cambisol (CXk), and an area of a deeper Typic Haplic Ta Eutrophic Cambisol (CXve), at six depths in five replications. Root images were digitized and the systems ImageJ and Safira used to determine root length and surface area. The line-intersect method modified by Tennant was used as reference; values of root length and surface area measured with the different systems were analyzed by Pearson's correlation coefficient and compared by the confidence interval and t-test. Both systems ImageJ and Safira had positive correlation coefficients with the reference method for root length and surface area data in CXk and CXve. The correlation coefficient ranged from 0.54 to 0.80, with lowest value observed for ImageJ in the measurement of surface area of roots sampled in CXve. The IC (95 %) revealed that root length measurements with Safira did not differ from that with the reference method in CXk (-77.3 to 244.0 mm). Regarding surface area measurements, Safira did not differ from the reference method for samples collected in CXk (-530.6 to 565.8 mm²) as well as in CXve (-4231 to 612.1 mm²). However, measurements with ImageJ were different from those obtained by the reference method, underestimating length and surface area in samples collected in CXk and CXve. Both ImageJ and Safira allow an identification of increases or decreases in root length and surface area. However, Safira results for root length and surface area are closer to the results obtained with the reference method.

Forestry plantations should be regarded as an alternative sustainable land-use system in degraded savannah areas. They contribute to the maintenance of productive processes in degraded soils that are of economic importance for local inhabitants; in addition, in the ecological sense, timber and non-timber products from planted forests reduce the exploitation pressure on native forests. Eucalyptus plantations on degraded savannahs in the northern Brazilian Amazon may help to reduce exploitation pressure on native forests. However, there is no information regarding the nutrients rates that would allow faster eucalyptus growth in that region. A trial was installed in an Yellow Latosol (Oxisol) soil type adopting a one-half-type fractionalfactorial design with four rates of N, P, and K. Functions were adjusted for the dependent variables height, diameter at breastheight (DBH), leaf tissue nutrient content, and soil-chemical attributes. Interaction N versus K was observed on tree heightwith a maximum of 7.8 m recorded at 200 kg ha-1 of N and 50 kg ha-1 of K. Phosphorus fertilization promoted greater DBH growth with maximum value at 120 kg ha-1 of P; however, the highest gain was obtained at 30 kg ha-1 of P. The NPK rates that maximized Eucalyptus camaldulensis growth were 200, 30, and 50 kg ha-1, respectively. Plantações de eucalipto, em áreas de lavrado degradadas na Amazônia Setentrional brasileira, devem contribuir para diminuir a pressão de exploração em florestas nativas. Porém, não há informações sobre as doses de nutrientes que permitem o rápido crescimento do eucalipto nesta região. Um experimento para avaliar a resposta à adubação do Eucalyptus camaldulensis foi instalado em Latossolo Amarelo, adotando o delineamento fatorial fracionário com quatro doses de nitrogênio (N), fósforo (P) e potássio (K). Funções foram ajustadas para as seguintes variáveis dependentes: altura, diâmetro à altura do peito (DAP), conteúdo de nutrientes nas folhas e atributos químicos do solo. Foi observada interação NxK para a altura, com um máximo de 7,8 metros registrados com a dose de 200 kg ha-1 de N e 50 kg ha-1 de K. A adubação fosfatada promoveu o maior crescimento do DAP com o valor máximo obtido com a dose de 120 kg ha-1 de P; O maior ganho, entretanto, foi obtido com a dose de 30 kg ha-1 de P. As doses de NPK que maximizaram o crescimento do Eucalyptus camaldulensis foram 200, 30 e 50 kg ha-1, respectivamente.

O objetivo deste trabalho foi verificar o papel da profundidade do solo e da microtopografia em aspectos nutricionais e produtivos de bananais irrigados. O estudo foi conduzido na Chapada do Apodi (CE), em área com variações na profundidade do solo. Os tratamentos foram sítios (locais) em diferentes classes de micro-relevo (côncavo, convexo e retilíneo) que abrangeram quatro profundidades de solo: A) 0,92 m; B) 0,77 m; C) 0,65 m; D) 0,52 m. Foram avaliados: altura da planta mãe (APM), altura da planta filha (APF), diâmetro do pseudocaule da planta mãe (DPPM), massa de folhas frescas (MFF) e secas (MFS), teores de fósforo (P), potássio (K), cálcio (Ca), enxofre (S) e sódio (Na) no tecido vegetal e massa dos cachos. O delineamento experimental foi inteiramente casualizado com sete repetições para avaliações de crescimento e cinco repetições para avaliações referentes à massa de folhas, estado nutricional e produção. A análise estatística foi feita pela ANOVA e DMS a 5% de significância. APM e DPPM foram maiores em A e C, enquanto que menores médias ocorreram no solo mais raso (D). MFF e MFS foram superiores em A e D que também apresentaram maior acúmulo de nutrientes nas folhas. Entretanto, maiores teores foliares e níveis adequados de P ocorreram em A, que também apresentou maior massa de cachos em relação aos solos mais rasos. Isto mostra que a profundidade efetiva do solo e o micro-relevo influenciam a absorção de nutrientes, o crescimento e o potencial produtivo de bananeiras irrigadas na Chapada do Apodi.The aim of this research was to verify whether soil depth affects aspects of mineral nutrition and yield potential of irrigated banana plantations. The study was carried out at Apodi Plateau (CE), Brazil, in an area characterized by soil depth variations. The treatments were sites in different microrelief classes (concave, convex and retilinea) with four different soil depths: A) 0.92 m; B) 0.77 m; C) 0.6 5m; D) 0.52 m. The following measures were done: high of mother plant (APM), high of daughter plant (APF), pseudosterm diameter of mother plant (DPPM), weight of fresh (MFF) and dry leaves (MFS), contents of phosphorus (P), potassium (K), calcium (Ca), sulphur (S) and sodium (Na) in plant tissue and bunch weight. Data were submitted to ANOVA and to least significant differences (LSD) with 5% of significance. APM and DPPM were higher in A and C, while the lower values were found in the shallow soil (D). Values of MFF and MFS were higher in both sites A and D that also presented larger amount of nutrients in plant leaves. However, higher amount and adequate levels of P in plant leaves were observed in the site A, on which plants presented higher bunch weigth. It showed that effective soil depth and soil microrelief have influence in nutrients uptake, plants growth, and productive potential of banana plants irrigated at Apodi Plateau.

O presente trabalho de pesquisa foi elaborado com o objetivo de comprovar a hipótese de que o cultivar de cana-de-açúcar RB83-5486, comparado ao RB83-5089, apresenta melhor distribuição radicular mediante cultivo em solo com menor teor de argila. O estudo foi realizado a partir de dois experimentos de campo desenvolvidos no município de Porto Feliz, SP. Os solos foram classificados como Nitossolo Vermelho eutroférrico latossólico (NV) e Latossolo Vermelho-Amarelo distrófico psamítico (LVA). No período entre a terceira e a quinta soca (2002 a 2004), os cultivares de cana-de-açúcar RB83-5486 e RB83-5089 foram avaliados a partir de estudos de atributos químicos e físicos do solo, do estado nutricional da cultura, da distribuição de raízes no perfil do solo e da produtividade e qualidade tecnológica da cana-de-açúcar. A distribuição de raízes foi avaliada utilizando-se o método da trincheira ou parede do perfil. Os resultados indicaram diferença na concentração de hidrogênio dos solos relacionada com a atividade dos cultivares na absorção de nutrientes. O teor foliar de potássio e enxofre foi maior para o cultivar RB83-5486. No LVA, ambos os cultivares apresentaram maior quantidade de raízes concentrando-se até os 18 cm de distância a partir das linhas de cana e até os 54 cm de profundidade. No NV, o cultivar RB83-5486 apresentou maior quantidade de raízes concentrando-se até 23 cm de distância a partir das linhas de cana e até os 46 cm de profundidade. Já o cultivar RB83-5089 mostrou distribuição do sistema radicular mais uniforme no NV. A produção de colmos foi maior no cultivar RB83-5089; contudo, a produção de açúcar foi maior em RB83-5486.Two field experiments were carried out in Porto Feliz, SP, Brazil, to test the hypothesis that in soils with low clay content, sugarcane genotype RB83 5486 has a better root system distribution than genotype RB83-5089. The two soils used were classified as Typic Kandiudalf and Typic Hapludox. Between the third and fifth ratoon (2002 to 2004), the development of the sugarcane genotypes RB83-5486 and RB83-5089 was evaluated by determining the chemical and physical soil attributes, crop nutritional status, root distribution in the soil profile, and stalk and sugar yield. Root distribution in the soil profile was evaluated by the trench method. Results show differences in hydrogen ion concentrations in both soils. These differences can be related to differences in the nutrient uptake of the studied genotypes. Potassium and sulphur contents in sugarcane leaves were higher in genotype RB83-5486. In the Typic Hapludox most part of the roots of both genotypes were concentrated at 0 to 18 cm from the cane rows and in the upper 54 cm. In the Typic Kandiudalf, most part of the roots of genotype RB83 5486 was concentrated at a distance of 0 to 23 cm from the sugarcane rows and in the upper 46 cm. The root system of genotype RB83-5089 was more evenly distributed in the Typic Kandiudalf. Stalk yield was higher for genotype RB83 5089, while sugar yield was higher for genotype RB83-5486.

Because of low P mobility in the soil, the effect of its position in relation to the root is of great practical significance, especially in soils with extreme P deficiency. Experiments with vegetables under this approach are not frequent. This work studies the influence of the position of phosphate fertilizer on nutrient absorption and on the production of vernalized garlic (Allium sativum L.) bulbs. Two experiments were carried out in pots (16 L) containing samples of a Typic Quartzipsamment and of a Typic Hapludox in a factorial scheme with four P doses (50, 100, 200, and 400 mg P dm-3) and five positions relative to the incorporation (I) or furrow application (S), where L1 = 100%I, L2 = 75%I and 25%S, L3 = 50%I and 50%S, L4 = 25%I and 75%S, and L5 = 100%S. Doses of fertilizer and forms of application influenced contents of phosphorus extracted by resin and from plant leaves, in both soils. Bulb yield increased with increasing P doses, and was influenced by the fertilizer's position only in the clayey soil.

O objetivo do trabalho foi avaliar o efeito de doses de Zn, aplicado como oxissulfato, nas formas granulada e em pó, em duas cultivares de arroz. O experimento foi realizado em casa de vegetação em vasos com 3 dm³ de um Latossolo Vermelho distrófico. Todos os vasos receberam calcário, macronutrientes e micronutrientes, com exceção do zinco. Foram aplicadas as doses de 0, 1, 2, 5 e 10 mg de Zn por dm³ de solo. A dose de 4 mg dm-3 de Zn aplicado como sulfato foi usada como padrão de referência. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. O oxissulfato em pó na cultivar IAC 165 e granular na IAC 202 possibilitaram produções de grãos semelhantes às obtidas com o sulfato de zinco. Houve diferença nos teores de Zn nas folhas e colmos das duas cultivares associados à maior produção de grãos. A cultivar IAC 202 foi mais eficiente na utilização de Zn no crescimento vegetativo e na produção de grãos. Os teores de Zn extraídos por Mehlich 1 e DTPA correlacionaram-se significativamente com as doses de Zn aplicadas e com os níveis de Zn no tecido vegetal. Houve correlação significativa entre os dois extratores em relação às doses de Zn aplicadas no solo.

Forestry plantations should be regarded as an alternative sustainable land-use system in degraded savannah areas. They contribute to the maintenance of productive processes in degraded soils that are of economic importance for local inhabitants; in addition, in the ecological sense, timber and non-timber products from planted forests reduce the exploitation pressure on native forests. Eucalyptus plantations on degraded savannahs in the northern Brazilian Amazon may help to reduce exploitation pressure on native forests. However, there is no information regarding the nutrients rates that would allow faster eucalyptus growth in that region. A trial was installed in an Yellow Latosol (Oxisol) soil type adopting a one-half-type fractional factorial design with four ates of N, P, and K. Functions were adjusted for the dependent variables height, diameter at breast height (DBH), leaf tissue nutrient content, and soil-chemical attributes. Interaction N versus K was observed on tree height with a maximum of 7.8 m recorded at 200 kg ha-1 of N and 50 kg ha-1 of K. Phosphorus fertilization promoted greater DBH growth with maximum value at 120 kg ha-1 of P; however, the highest gain was obtained at 30 kg ha-1 of P. The NPK rates that maximized Eucalyptus camaldulensis growth were 200, 30, and 50 kg ha-1, respectively.

ABSTRACT Soils in semi-arid regions have been degraded by overgrazing, which reduces the production capacity and, in certain situations, leads to desertification. An alternative to recover degraded areas is the fallow period, which works through the resilience of the soil itself, increasing the supply of organic matter and improving soil physical properties. Thus, the objective of this study was to test the hypothesis that 14-year grazing exclusion improves soil physical and chemical attributes in degraded areas under desertification. The study was conducted in Irauçuba, Ceará State, Brazil. The experimental design was completely randomized, in a 4 x 2 factorial scheme corresponding to four areas and two managements (overgrazing and fallow), with four replicates, plus an area with native vegetation (reference), with characteristics of secondary vegetation. Fallow led to improvements in soil physical and chemical attributes after 14 years; however, in comparison to the study conducted in the same area with a 7-year fallow period, there were few alterations. Organic carbon content was higher in fallow areas than in overgrazing areas, and the fraction in highest proportion was the mineral-associated organic carbon.

A Chapada do Apodi caracteriza-se como importante pólo agrícola no estado do Ceará. Apesar da homogeneidade de clima, relevo e material de origem, seus solos apresentam grande variabilidade de atributos, muitas vezes em pequenas escalas espaciais, indicando a necessidade de manejos distintos. O presente trabalho teve como objetivo estudar a influência do microrrelevo na variabilidade espacial das diferentes frações granulométricas dos solos da Chapada do Apodi. Para isso, foi realizado levantamento planialtimétrico em uma área de 102 ha, seguido de tradagens para coleta das amostras de solo e determinação da profundidade efetiva. As amostras foram submetidas à análise granulométrica e os dados foram tratados por meio da estatística descritiva e da geoestatística, utilizando-se semivariogramas e mapas de krigagem. Com base nas formas de microrelevo, o local de estudo foi compartimentado em 03 superfícies distintas (côncava, convexa e retilínea). Por meio dos resultados foi identificada clara influência do microrrelevo na distribuição das frações granulométricas. Maiores teores de argila e maiores profundidades de solos foram encontrados na superfície côncava. Estes resultados são indicativos de maior ação da pedogênese nos solos desta porção do terreno em resposta à existência de fluxos hídricos convergentes. A ocorrência de maiores teores de areia e solos mais rasos na superfície convexa e mais elevada indica menor ação da pedogênese e maior intensidade do processo de erosão seletiva. O uso da geoestatística contribuiu para a identificação de áreas com necessidades diferenciadas de manejo, servindo como importante ferramenta para a tomada de decisões, especialmente relacionadas à irrigação.