Mirian Cristina Gomes Costa

Microrrelevo e a distribuição de frações granulométricas em Cambissolos de origem calcária

A Chapada do Apodi caracteriza-se como importante polo agricola no estado do Ceara. 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 influencia do microrrelevo na variabilidade espacial das diferentes fracoes granulometricas dos solos da Chapada do Apodi. Para isso, foi realizado levantamento planialtimetrico em uma area de 102 ha, seguido de tradagens para coleta das amostras de solo e determinacao da profundidade efetiva. As amostras foram submetidas a analise granulometrica e os dados foram tratados por meio da estatistica descritiva e da geoestatistica, utilizando-se semivariogramas e mapas de krigagem. Com base nas formas de microrelevo, o local de estudo foi compartimentado em 03 superficies distintas (concava, convexa e retilinea). Por meio dos resultados foi identificada clara influencia do microrrelevo na distribuicao das fracoes granulometricas. Maiores teores de argila e maiores profundidades de solos foram encontrados na superficie concava. Estes resultados sao indicativos de maior acao da pedogenese nos solos desta porcao do terreno em resposta a existencia de fluxos hidricos convergentes. A ocorrencia de maiores teores de areia e solos mais rasos na superficie convexa e mais elevada indica menor acao da pedogenese e maior intensidade do processo de erosao seletiva. O uso da geoestatistica contribuiu para a identificacao de areas com necessidades diferenciadas de manejo, servindo como importante ferramenta para a tomada de decisoes, especialmente relacionadas a irrigacao.

Variabilidade espacial dos atributos químicos do solo, associada ao microrrelevo

The variability of soil chemical attributes is influenced by complex interactions between factors and processes of soil formation. This study hypothesized that soil chemical attribute varies with microrelief to change management recommendations for agricultural use. The relief was separated in compartments and surfaces were studied with the objective to determine the soil chemical properties and to evaluate the spatial dependence of these attributes. Sampling grid was established in an area of ​​102 ha at Agricultural Farm Famosa localized in Plateau of Apodi, CE. The soil was derived from limestone and was collected at 92 points spaced at 200 by 100 m and in 0-20 and 20-40 cm depths. With the topographic data a terrain modeling was generated and based on the identified microrelief, the study site was divided into surfaces. Data were analysed using descriptive statistics and spatial variability analysis, with the semivariograms adjustments and kriging maps. Soil chemical attributes showed spatial variability at the convex, concave and rectilinear microrelief, being intensified by water flow at the depths.

Public-domain software for root image analysis

Procurando maior eficiencia no estudo de raizes, sistemas computacionais tem sido desenvolvidos para analisar imagens digitais. O ImageJ e o Safira sao sistemas de dominio publico que podem ser utilizados na analise de raizes lavadas. Porem, supoe-se que ha diferencas nos atributos radiculares determinados por meio do ImageJ e Safira. Este estudo foi realizado para comparar valores de comprimento e area superficial de raizes, obtidos com os dois sistemas, com os valores alcancados por meio do metodo de referencia. Amostras de raizes foram coletadas em bananal em areas de Cambissolo Haplico carbonatico tipico (CXk), mais raso, e de Cambissolo Haplico Ta eutrofico tipico (CXve), mais profundo, em seis camadas e cinco repeticoes. As raizes foram escaneadas e os sistemas ImageJ e Safira foram utilizados para determinar comprimento e area superficial radicular. Utilizando o metodo da intersecao modificado por Tennant como referencia, valores de comprimento e area obtidos pelos sistemas foram analisados a partir do coeficiente de correlacao de Pearson e comparados pelo intervalo de confianca e pelo teste t. Ambos os sistemas apresentaram coeficiente de correlacao positivo com o metodo de referencia para medidas de comprimento e area superficial em CXk e CXve. O coeficiente de correlacao variou de 0,54 a 0,80, com menor valor observado para o ImageJ na determinacao da area superficial de amostras coletadas no CXve. O IC (95 %) revelou que as medidas de comprimento radicular com o Safira nao diferiram do metodo de referencia no CXk (-77,3 a 244,0 mm). Quanto a area superficial, o Safira nao diferiu do metodo de referencia, tanto para amostras coletadas em CXk (-530,6 a 565,8 mm2) como nas provenientes de CXve (-423,1 a 612,1 mm2). Ja as medidas feitas com o ImageJ diferiram do metodo de referencia, com valores subestimados de comprimento e area superficial radicular em amostras coletadas em CXk e CXve. Os dois sistemas permitem identificar aumento ou diminuicao no comprimento e na area superficial de raizes lavadas. Porem, o Safira resulta em valores de comprimento e de area superficial radicular mais proximos aos obtidos com o metodo de referencia.

Profundidade do solo e micro-relevo em bananais irrigados: impactos na nutrição mineral e potencial produtivo

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.

Profundidade e atributos físicos do solo e seus impactos nas raízes de bananeiras

The banana tree may have hampered its production if grown in soils with physical restrictions. The aim of this study was to verify if the physical attributes of shallow soils undermine the roots of banana tree plants. The study was conducted in the Apodi Plateau (CE), where soils were compared with two actual depths: shallow (approximately 0.57 m depth, more sandy) and deep (approximately 1.16 m depth, more clayey) and six sampling depths of soil and roots (0-10, 10-20, 20-30, 30-40, 40-50 and 50-60 cm). In the soil samples were determined the following physical attributes: water retention curve, bulk density, porosity, particle size and particle density. The soil resistance to penetration (RP) was assessed in the field using an impact penetrometer with five repetitions at 60 cm depth. To study the roots, samples were collected with a probe, and the washed roots were analyzed through images, being determined: length, area and total volume and diameter classes. The deep soil had higher clay content, higher microporosity and total porosity, which contributed to the higher water retention. Density of soils and particles were higher in two layers of the shallow soil, as well as the RP which reached 5.1 MPa. The roots of banana tree were favored in deep soil in which were found thicker (2.2 to 6.6 mm) and thinner (0.68 to 0.79 mm) roots, contributing to the support of plants and the absorption of water and nutrients.

Characterization of organic wastes and effects of their application on the soil.

The agricultural farming activities generate organic waste whose indiscriminate deposition can be prejudicial to the environment. However, careful application of these wastes as organic fertilizers it is a possibility to improve soil fertility. This study aimed to confirm the hypotheses that organic wastes produced in various production chains in the semi-arid region of Ceara have contents of nutrients that give them potential as organic fertilizers and, since they are used as organic fertilizers, these residues improve the chemical soil attributes. Nutrient contents were determined at the laboratory and then the wastes were placed in decomposition bags and applied in a Fluvic Neosol. Soil samples were collected in the 0-0.10 m layer 90 days after wastes were applied. The residues presented nutrient contents that allow their use as organic fertilizers, except the shrimp farming residue that presented sodium content above that allowed by legislation, resulting also in higher element contents in the soil. In addition, the shrimp farming showed the lowest organic carbon content in relation to others chemical elements. The residues of the poultry industry and the compound made with residues of small ruminants presented the highest of nitrogen and phosphorus levels. The carnauba residue was associated with phosphorus immobilization because it presented C/P ratio higher than 300.

Changes in attributes of soils subjected to fallow in desertification hotspot

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 Iraucuba, Ceara 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.

SEEDLING GROWTH OF TREE SPECIES UNDER DOSES OF HYDROGEL AND TWO LEVELS OF LUMINOSITY

http://dx.doi.org/10.1590/1806-90882018000100012 ABSTRACT – Hydrogels (polyacrylamide compounds) are recommended in agriculture and forestry as soil conditioners because they are able to absorb water and increase its stocks in the soil. The aim of this study was to determine the most suitable dose of hydrogel to establish seedlings of Enterolobium contortisilliquum (Vell.) Morong under two levels of luminosity. Seedlings of Enterolobium contortisilliquum (Vell.) Morong were planted in pots, following a design of subdivided plots, consisting of two levels of luminosity in the plots: full sun and 50% luminosity, and 10 doses of hydrogel in the sub-plots: 0.0, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0 g L. Seventy-two days after the seedlings were transplanted to the pots, plant height and diameter were determined, together with the height to diameter ratio, root length and diameter, shoot and root dry weight, and the shoot to root ratio. The lowest ratios between height and stem diameter (8.50 and 8.68) occurred in the seedlings in full sun at the doses of 0 and 2 g hydrogel L respectively. For shaded seedlings the lowest ratio (8.14) occurred at the dose of 3.0 g L, but with a lower coefficient of determination (R = 0.68). Shoot dry weight increased with the dose of 2 g L in full sun, and 3.5 g L under shaded conditions. The doses of hydrogel giving the best initial development in seedlings under evaluation were 2 g L in full sun and 3.5 g L in the shaded environment. Although a response by the species to the doses of hydrogel was found, the benefits of the polymer were not evident under the conditions of the present study.

Fistulization of J-PEG Jejunal Tube into the Colon in a Patient Treated with Duodopa® Infusion: A Case Report

The continuous delivery of a levodopa/carbidopa gel suspension (Duodopa®) into the small bowel through a jejunal tube inserted via percutaneous endoscopic gastrostomy represents a new treatment method in advanced Parkinson disease. Some severe device-related complications have been described in the last few years. Some of them are associated with phytobezoar formation at the pigtail of the catheter. We present the case of a Parkinson disease patient treated with the Duodopa infusion system complicated by jejunal tube fistulization into the colon. We suggest a possible treatment strategy for this complication, which has not been described in the literature to date.

Fallow Reduces Soil Losses and Increases Carbon Stock in Caatinga

This study aimed at evaluating whether 10 years of fallow was sufficient to restore a degraded hillslope in the semi-arid Caatinga biome, Brazil. For this purpose, runoff, erosion, loss of nutrients and organic carbon were measured on two comparable hillslopes: one was left fallow and the other degraded caused by overgrazing. Fallow management reduced runoff (36%), soil loss (65%) and organic carbon loss (81%) in comparison with the degraded hillslope. However, the fallow did not significantly reduce nutrient loss. Animal grazing has been shown to influence the nutrient cycle in the soil. The loss of organic carbon shows significant correlation with the loss of other nutrients, and may be used to estimate nutrient loss. Results show that a decade of fallow did not promote significant changes in the loss of nutrients, but was enough to reduce runoff, erosion and loss of organic carbon.