Soil management and nitrogen fertilization for sprinkler-irrigated upland rice cultivars

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Recovery of soil physical properties by green manure, liming, gypsum and pasture and spontaneous native species

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Caenorhabditis elegans as a model to screen plant extracts and compounds as natural anthelmintics for veterinary use

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

The Allium cepa bioassay to evaluate landfarming soil, before and after the addition of rice hulls to accelerate organic pollutants biodegradation

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Comparative gas exchange performance during the wet season of three Brazilian Styrax species under habitat conditions of cerrado vegetation types differing in soil water availability and crown density

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation

In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p.p'-DDT (DDT) and p.p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments,Triton X-100(TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT). 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC(eff)). The wastewater obtained was then treated using a solar photo-Fenton process. After 6 h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu. Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation. (C) 2009 Elsevier B.V. All rights reserved.

Diesel Degradation in Soil by Fenton Process

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Gravimetric determination of soil organic matter

Avaliou-se o m��todo de determina����o gravim��trica da mat��ria org��nica do solo pela perda de massa por incinera����o a 300��C e comparou-se com o carbono determinado pelo m��todo Walkley-Black. Os dois m��todos foram correlacionados positivamente com a seguinte equa����o de regress��o linear: y = 3,720x + 0,2914. r = 0,937. O coeficiente. 3,720 foi maior do que os encontrados na literatura. que variaram de 1,68 a 2,13. Esta diferen��a foi atribu��da ao maior grau de oxida����o da mat��ria org��nica dos solos das regi��es tropicais. O m��todo de incinera����o �� aplic��vel para determina����o do C do solo em rotina. O m��todo n��o contamina o meio ambiente com metal t��xico (Cr6+) e n��o oferece riscos aos analistas com o uso de ��cido sulf��rico concentrado.

Spatial variability of the physical and mineralogical properties of the soil from the areas with variation in landscape shapes

Este trabalho teve como objetivo avaliar a influ��ncia das formas do relevo na variabilidade espacial de atributos f��sicos e suas rela����es com a mineralogia da argila de um Latossolo Vermelho eutrof��rrico, utilizando a t��cnica da geoestat��stica. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, nas profundidades de 0,0-0,2 m, 0,2-0,4 m e 0,4-0,6 m para os atributos f��sicos e 0,6-0,8 m para os atributos mineral��gicos. Os valores m��dios para a densidade do solo e resist��ncia do solo �� penetra����o s��o maiores no compartimento I onde a rela����o Ct/Ct+Gb �� relativamente maior, indicando a presen��a de maior teor de caulinita. No compartimento II a condutividade hidr��ulica e a macroporsidade s��o maiores, influenciados provavelmente pelo predom��nio da gibbsita. Portanto, conclui-se que a identifica����o das pedoformas �� muito eficiente para compreender a variabilidade espacial de propriedades do solo. Sendo que, as varia����es na forma da paisagem promovem variabilidade espacial diferenciada das propriedades f��sicas e mineral��gicas do solo.

A review on soil carbon accumulation due to the management change of major Brazilian agricultural activities

��reas agr��colas trocam enormes fluxos de CO2, oferecendo uma oportunidade para mitigar o efeito estufa. Neste trabalho, estudou-se o potencial de sequestro de carbono em raz��o da convers��o no manejo das principais atividades agr��colas do Brasil. Dados de v��rios estudos t��m indicado que no sistema soja/milho e nas respectivas rota����es, ocorre um sequestro de carbono no solo significativo ao longo dos anos de convers��o do plantio convencional para o plantio direto, com uma m��dia de 0,41 Mg C ha-1 ano-1. O mesmo efeito tem sido observado nos canaviais, por��m h�� maiores ac��mulos de carbono no solo quando as ��reas de cana-de-a����car s��o convertidas da colheita baseada na queima para a mecanizada, em que grandes quantidades de palha s��o deixadas na superf��cie do solo (1,8 Mg C ha-1 ano-1). Esse maior potencial de ac��mulo de carbono no solo nos canaviais, comparado com outras culturas, est�� diretamente relacionado com a maior produ����o prim��ria dessa cultura. Apesar disso, muito desse potencial de sequestro �� perdido, uma vez que os canaviais s��o reformados, sob preparo intensivo do solo. As ��reas de pasto mostram uma deple����o nos estoques de carbono, quando convertidas de ��reas naturais; por��m, a integra����o dessas ��reas com agricultura pode promover o aumento nos estoques de carbono do solo. Os trabalhos t��m mostrado que as principais atividades agr��colas do Brasil possuem um grande potencial de mitiga����o, especialmente na forma de ac��mulo de carbono no solo, sendo uma oportunidade para estrat��gias futuras.

Performance of a reciprocal shaker in mechanical dispersion of soil samples for particle-size analysis

A dispers��o da amostra de solo �� uma etapa fundamental da an��lise granulom��trica, sendo realizada mediante o uso de dispersantes qu��micos e agita����o mec��nica. O objetivo deste trabalho foi avaliar a efici��ncia de mesa agitadora reciprocante de baixa rota����o na dispers��o mec��nica de amostras de solos de diferentes classes texturais. Foram realizadas an��lises granulom��tricas em 61 amostras com quatro repeti����es, empregando o m��todo da pipeta para determina����o da fra����o argila e tamisagem para determina����o das fra����es areia grossa, areia fina e areia total, sendo o silte determinado por diferen��a. Na avalia����o de desempenho, os resultados obtidos com uso da mesa agitadora reciprocante (MAR) foram comparados com dados dispon��veis para as mesmas amostras oriundos de relat��rios do Ensaio de Profici��ncia IAC para Laborat��rios de An��lises de Solos - Prolab/IAC. An��lises de acur��cia foram realizadas com base nos valores dos intervalos de confian��a definidos para cada fra����o granulom��trica componente de cada amostra ensaiada. Indicadores gr��ficos tamb��m foram utilizados na compara����o de dados, por meio de dispers��o e ajuste linear. A estat��stica descritiva indicou preponder��ncia de baixa variabilidade em mais de 90 % dos resultados obtidos para as amostras de texturas arenosa, m��dia e argilosa e em 68 % dos obtidos para as amostras de textura muito argilosa, indicando boa repetibilidade dos resultados obtidos com a MAR. M��dia variabilidade foi mais frequentemente associada �� fra����o silte, seguida da fra����o areia fina. Os resultados das an��lises de sensibilidade indicam acur��cia de 100 % nas tr��s fra����es granulom��tricas - areia total, silte e argila - para todas as amostras analisadas pertencentes ��s classes texturais muito argilosa, argilosa e m��dia. Para as nove amostras de textura arenosa, a acur��cia m��dia foi de 85,2 %, e os maiores desvios ocorreram em rela����o �� fra����o silte. Nas aproxima����es lineares, coeficientes de correla����o igual (silte) ou superiores (areia total e argila) a 0,93, bem como diferen��as menores do que 0,16 entre os coeficientes angulares das retas e o valor unit��rio, indicam alta correla����o entre os resultados de refer��ncia (Prolab/IAC) e os obtidos nos ensaios com a MAR. Conclui-se pelo desempenho satisfat��rio da mesa agitadora reciprocante de baixa rota����o para dispers��o mec��nica de amostras de solo de diferentes classes texturais para fins de an��lise granulom��trica, permitindo recomendar o uso alternativo do equipamento quando se emprega agita����o lenta. As vantagens do uso do equipamento nacional incluem o baixo custo, a possibilidade de an��lise simult��nea de grande n��mero de amostras e o uso de frascos comuns, de vidro ou de pl��stico, baratos e de f��cil reposi����o.

Soil loss risk and habitat quality in streams of a meso-scale river basin

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

The influence of soil and landfill leachate microorganisms in the degradation of PVC/PCL films cast from DMF

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Soil CO2 efflux following rotary tillage of a tropical soil

Stopping the increase of atmospheric CO2 level is an important task and information on how to implement adjustments on tillage practices could help lower Soil CO2 emissions would be helpful. We describe how rotary tiller use on a red latosol affected Soil CO2 efflux. The impact of changing blade rotation speed and rear shield position on soil CO2 efflux was investigated. Significant differences among treatments were observed up to 10 days after tillage. Cumulative CO2 efflux was as much as 40% greater when blade rotation of 216 rpm and a lowered rear shield was compared to blade rotation of 122 rpm and raised shield. This preliminary work suggests that adjusting rotary tiller settings could help reduce CO2 efflux close to that of undisturbed soil, thereby helping to conserve soil carbon in tropical environments. (C) 2004 Elsevier B.V. All rights reserved.