ORGANIC MATTER AND HUMIC FRACTIONS OF A HAPLIC ACRISOL AS AFFECTED BY COMPOSTED PIG SLURRY

The goal of this study was to investigate the effect of composted pig slurry (PS) on the organic matter concentration and distribution of humic acid (HA), fulvic acid (FA) and humin (HU) fractions. The fractions were quantified following the addition of composted PS to the soil, which was produced with no acidification (T2) or with acidification with H3PO4 (T3); and in soil without compost addition (T1). The HA chemical composition was analyzed by FTIR spectroscopy. The addition of the two composts did not change the soil carbon concentration but affected the distribution of the humic fractions. For the three treatments, the carbon concentration of humic substances increased until 52 days following compost addition, with more pronounced increases with the addition of non-acidified PS compost (14.5 g kg-1) and acidified PS compost (15.1 g kg-1). This increase was reflected in both the FA and HA concentrations. The addition of compost with PS acidification resulted in the formation of larger humic micelles (HA) with higher aromatic content and fewer functional groups than the non-acidified PS compost. These findings, together with a lower proportion of carbohydrate-type structures, indicated the presence of more stable humic micelles in the soil treated with acidified PS compost.

A NOVEL METHOD FOR THE DETERMINATION OF TRACE THORIUM BY DISPERSIVE LIQUID-LIQUID MICROEXTRACTION BASED ON SOLIDIFICATION OF FLOATING ORGANIC DROP

In this study, dispersive liquid-liquid microextraction based on the solidification of floating organic droplets was used for the preconcentration and determination of thorium in the water samples. In this method, acetone and 1-undecanol were used as disperser and extraction solvents, respectively, and the ligand 1-(2-thenoyl)-3,3,3-trifluoracetone reagent (TTA) and Aliquat 336 was used as a chelating agent and an ion-paring reagent, for the extraction of thorium, respectively. Inductively coupled plasma-optical emission spectrometry was applied for the quantitation of the analyte after preconcentration. The effect of various factors, such as the extraction and disperser solvent, sample pH, concentration of TTA and concentration of aliquat336 were investigated. Under the optimum conditions, the calibration graph was linear within the thorium content range of 1.0-250 µg L-1 with a detection limit of 0.2 µg L-1. The method was also successfully applied for the determination of thorium in the different water samples.

Effect of organic amendments on sclerotial germination, mycelial growth, and Sclerotium rolfsii-induced diseases

The addition of organic residues to soil is an option to control some soil-borne diseases. Benzaldehyde and powders of kudzu (Pueraria lobata), velvetbean (Mucuna deeringiana), and pine-bark (Pinus elliottii and P. taeda) added to soil could reduce certain soil-borne diseases. This study evaluated the effects of benzaldehyde and the dried powders of kudzu, velvetbean, and pine-bark as soil amendments on germination and formation of sclerotia, on mycelial growth of Sclerotium rolfsii, on plant survival, and disease incidence. The data showed that high amounts of benzaldehyde (0.4 ml kg-1 of soil) and velvetbean (100 g kg-1) inhibited S. rolfsii mycelial growth and sclerotium germination. However, low amounts of benzaldehyde (0.1 ml kg-1), kudzu (25 g kg-1), and pine-bark (25 g kg-1) stimulated mycelial growth and sclerotium germination. Kudzu (25-100 g kg-1) and velvetbean (25-100 g kg-1) inhibited the formation of sclerotia. Nevertheless, benzaldehyde at 0.2 and 0.4 ml kg-1 stimulated the formation of sclerotia. Kudzu (50 and 100 g kg-1) and pine-bark (50 g kg-1) favored the colonization of sclerotia by Trichoderma sp. The numbers of soybean (Glycine max) plants were higher and diseased plants were lower than the non-amend soil in the following treatments: kudzu (50 and 100 g kg-1), velvetbean (50 and 100 g kg-1), and pine-bark (50 g kg-1). Disease severity on tomato (Lycopersicon esculentum) plants was low in soil treated with kudzu or velvetbean (30 and 35 g kg-1) and pine-bark (35 g kg-1). Dried powders of kudzu, velvetbean, or pine-bark added to soil can reduce disease by reducing pathogen inoculum.

Viscometric investigations and molecular interactions of some derivatives of 5-substituted indole dihydropyrimidines in mixed organic solvents

Colloid chemical behavior of indole dihydropyrimidines in non-aqueous solvent mixture benzene-methanol of varying composition has been investigated by viscometric measurements at 303K± 0.1. The viscosity of the system increases with the increase in concentration. The Trend Change Point (TCP) values have been determined by intersection of two straight lines, which are found to be dependent on the composition of solvent mixtures. The study confirms that the nature of synthesized compounds agglomerate formed below and above 50% benzene concentration is quite different. The viscometric data have been analyzed in terms of Einstein, Vand, Moulik and Jones-Dole equations. These well known equations have been successfully applied to explain the results of viscosity measurements and the viscometric parameters show that the behavior of compound changes in the proximity of 50% benzene concentration.

Nematicidal effect of volatile organic compounds (VOCs) on the plant-parasitic nematode Meloidogyne javanica

Previous studies have demonstrated that volatile organic compounds (VOCs), produced by the yeast Saccharomyces cerevisiae, were able to inhibit the development of phytopathogenic fungi. In this context, the nematicidal potential of the synthetic mixture of VOCs, constituted of alcohols and esters, was evaluated for the control of the root-knot nematode Meloidogyne javanica, which causes losses to crops of high economic value. The fumigation of substrate containing second-stage juveniles with VOCs exhibited nematicidal effect higher than 30% for the lowest concentration tested (33.3 µL g-1 substrate), whereas at 66.6 and 133.3 µL g-1 substrate, the nematode mortality was 100%. The present results stimulate other studies on VOCs for nematode management.

Influência da saturação por bases e do fósforo no crescimento de mudas de angico-branco

Este trabalho teve por objetivo avaliar o desempenho de mudas da espécie angico-branco (Anadenanthera colubrina (Vell.) Brenan), em condições diferenciadas de disponibilidade de fósforo no solo e de saturação por bases. Os tratamentos foram representados por um fatorial de seis níveis de P (0, 100, 200, 300, 400 e 500 mg/dm³) por cinco níveis de saturação por bases (original = 24, 40, 50, 60 e 70%), sendo dispostos no delineamento em blocos ao acaso, com cinco repetições. Aos 170 dias após a semeadura, foram feitas medições de altura e diâmetro do coleto de todas as plantas, as quais foram colhidas, separadas em raiz e parte aérea e postas a secar para obtenção do peso de matéria seca. A adição da mistura corretiva ao substrato não apresentou resposta significativa por parte da espécie estudada. Essa falta de resposta pode estar relacionada ao fato de que os teores de Ca (0,9 cmol c/dm³) e de Mg (0,4 cmol c/dm³) contidos no solo utilizado tenham sido suficientes para suprir as necessidades das plantas nessa fase. No entanto, observou-se que o angico-branco responde positivamente à aplicação de P. Considerando-se a saturação por bases de 40 e 60%, as doses de P que proporcionaram 90% de produção máxima, com base na produção de matéria seca da parte aérea, foram de 127 e 126 mg/dm³, respectivamente. De acordo com o modelo ajustado para P recuperado, em função do P adicionado, a dose que proporcionará essa disponibilidade de fósforo aos 170 dias é de 976,2 mg/dm³ para V=40% e de 1.277,3 mg/dm³ para V=60%. O nível crítico de P no solo, pelo extrator Mehlich-1, foi de 13,88 mg/dm³ (V=40%) e de 12,87 mg/dm³ (V=60%) e na parte aérea, de 0,14 dag/kg (V=40%) e de 0,12 dag/kg (V=60%).

Crescimento e qualidade de mudas de Anadenanthera macrocarpa (Benth.) brenan em resposta à saturação por bases do substrato

O presente trabalho foi desenvolvido com o objetivo de verificar a influência da saturação por bases do substrato sobre o crescimento e a qualidade de mudas de Anadenanthera macrocarpa (angico-vermelho). O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições por tratamento. Foram empregados três solos como substrato, e para cada um deles a saturação por bases original foi elevada aos seguintes valores: Latossolo Distrófico, 30,0; 50,0; e 70,0%; Latossolo Álico, 25,0; 45,0; e 65,0%; e Argissolo, 50,0; 60,0; e 70,0%. Foram avaliados os parâmetros morfológicos das mudas, suas relações e o índice de qualidade de Dickson. A saturação por bases não teve influência em nenhum dos parâmetros avaliados quando o substrato utilizado foi o argissolo. Exceto no diâmetro do coleto, a elevação da saturação por bases exerceu influência significativa, com padrão linear sobre os parâmetros morfológicos, suas relações e no índice de qualidade de Dickson para mudas produzidas no Latossolo Distrófico. No Latossolo Álico foi observado influência significativa com um comportamento quadrático sobre as características avaliadas, sendo os melhores crescimentos e qualidade encontrados quando a saturação por bases estava próxima de 50,0%.

Influência da saturação por bases e da relação Ca:Mg do substrato sobre o crescimento inicial de jacarandá-da-bahia (Dalbergia nigra (Vell.) Fr. All. ex Benth.)

Com o objetivo de verificar a influência da saturação por bases do substrato sobre o crescimento e qualidade de mudas de Dalbergia nigra (jacarandá-da-bahia), desenvolveu-se este trabalho. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições por tratamento, e cada vaso com uma planta foi considerado uma repetição. Foram utilizados três tipos de solo como substrato (dois latossolos e um argissolo), e em cada um deles a saturação por bases original foi elevada para os seguintes valores: latossolo distrófico: 30,0, 50,0 e 70,0%; Latossolo álico: 25,0; 45,0; e 65,0%; Argissolo: 50,0; 60,0; e 70,0%. Para avaliar os efeitos das diferentes relações Ca:Mg do corretivo, elevou-se a saturação por bases do solo para 60,0% no argissolo, 50,0% no latossolo distrófico e 45,0% no latossolo álico, utilizando como corretivo uma mistura de CaCO3 e MgCO3 nas seguintes relações estequiométricas: 1:0, 1:1, 2:1, 3:1 e 4:1. Foram avaliados os parâmetros morfológicos das mudas, suas relações e o índice de qualidade de Dickson. Observou-se uma resposta linear quando as diferentes relações Ca:Mg do corretivo foram analisadas em função da variação do peso de matéria seca da parte aérea, bem como o peso de matéria seca total quando o substrato era o Argissolo, porém nos demais substratos e características não houve influência significativa. Pode-se concluir que, quando a saturação original do solo for igual ou superior a 14,0% no Latossolo distrófico e 4% no Latossolo álico, não há necessidade de se proceder à correção do solo, enquanto no Argissolo as mudas de melhor qualidade são obtidas quando a saturação está em torno de 60,0%.

Influência da saturação por bases do substrato no crescimento e qualidade de mudas Machaerium nictitans (Vell.) Benth.

Este trabalho foi desenvolvido com o objetivo de verificar a influência da saturação por bases do substrato no crescimento e qualidade de mudas de Machaerium nictitans. O delineamento utilizado foi em blocos ao acaso com quatro repetições. Como substrato foram empregados três diferentes solos, sendo em cada um deles a saturação por bases original elevada para os seguintes valores: Argissolo Vermelho-Amarelo 50, 60 e 70%, Latossolo Vermelho-Amarelo distrófico 30, 50 e 70% e Latossolo Vermelho-Amarelo álico 25, 45 e 65%. Foram avaliadas as características morfológicas das mudas, altura da parte aérea e diâmetro do coleto; peso de matéria seca da parte aérea, raízes e total, bem como as relações entre a altura da parte área e o diâmetro do coleto, altura da parte aérea e seu peso de matéria seca, peso de matéria seca da parte aérea e peso de matéria seca das raízes; e o índice de qualidade de Dickson. Com base nos dados, foi possível concluir que: as melhores mudas de Machaerium nictitans no Argissolo Vermelho-Amarelo foram obtidas na saturação por bases de 60%, no Latossolo Vermelho-Amarelo distrófico na saturação por bases de 70% e no Latossolo Vermelho-Amarelo álico na saturação por bases de 40%.

Estruturação topológica de grandes bases de dados de bacias hidrográficas

O presente trabalho teve como objetivo avaliar o método para delimitação da bacia de contribuição à montante de um ponto selecionado sobre o hidrografia e a obtenção das respectivas características morfométricas, a partir de bases de dados estruturadas topologicamente. Para tanto, utilizou-se o aplicativo Hidrodata 2.0, desenvolvido para o ArcINFO workstation, comparando os seus resultados com os do processo convencional. Os resultados comprovaram que o tempo de processamento demandado para delimitação de bacias e extração de suas características morfométricas a partir de uma base de dados estruturada topologicamente se manteve baixo e constante. Concluiu-se que o método apresentado poderá ser aplicado em qualquer bacia hidrográfica, independentemente do seu tamanho, mesmo com o uso de computadores de configuração mais modesta.

Soil organic matter pools in a tropical savanna under agroforestry system in Northeastern Brazil

This study aimed at quantifying total organic carbon stocks and its pools in Acrisol under agroforestry systems with six (AFS6) and thirteen years old (AFS13), slash-and-burn agriculture (SBA) and savanna native forest (SNF) in northeastern Brazil. Soil samples were collected at 0-0.05 m, 0.05-0.10 m, 0.10-0.20 m and 0.20-0.40 m depths in the dry and rainy seasons to evaluate total organic carbon (TOC) stocks and labile carbon (LC), fulvic acid fraction (C-FAF), humic acid fraction (C-HAF), humin (C-HF) and microbial biomass carbon (Cmic) contents. Additionally, carbon management index (CMI) was determined. Higher TOC stocks (97.7 and 81.8 Mg ha-1 for the 0-0.40 m depth in the dry and rainy seasons, respectively) and LC, humic substances and Cmic contents were observed in the AFS13 in all the depths. CMI also was higher in the AFS13 (0-0. 05 m: 158 and 86; 0.05-0.10 m: 171 and 67, respectively for the dry and rainy seasons) especially when compared to the SBA (0-0.05 m: 5.6 and 5.4; 0.05-0.10 m: 5.3 and 5.8, respectively for dry and rainy seasons). The agroforestry systems increased soil quality through the conservation of organic matter and can be considered an excellent strategy to assurance sustainability in tropical soil of Northeastern Brazil

INTERACTIONS OF BIOCHAR AND ORGANIC COMPOUND FOR SEEDLINGS PRODUCTION OF Magonia pubescens A. St.-Hil.

ABSTRACTThe objective of this study was to test the hypothesis that biochar, applied with cattle manure, promotes better development of seedlings of Magonia pubescens St. Hil. The experiment was conducted at the State University of Mato Grosso, Nova Xavantina, Brazil, in 2011. We used a completely randomized design, with twelve treatments and three replications. The substrates formed by the higher levels of cattle manure plus biochar (30%) provided better results of height, diameter and aerial biomass. However, the Dickson Quality Index has not confirmed the quality of seedlings in these treatments. We also observed that the doses of biochar (20 and 30%) when added separately to the Latosol, are not efficient for the growth improvement of the seedlings. Based on the present results, we validate the hypothesis that substrates formed with a mixture of cattle manure and biochar are effective to improve the production of seedlings of M. pubescens.

SOIL ORGANIC CARBON, CARBON STOCK AND THEIR RELATIONSHIPS TO PHYSICAL ATTRIBUTES UNDER FOREST SOILS IN CENTRAL AMAZONIA

ABSTRACT The soil carbon under Amazonian forests has an important roles in global changing, making information on the soil content and depths of these stocks are considerable interest in efforts to quantify soil carbon emissions to the atmosphere.This study quantified the content and soil organic carbon stock under primary forest up to 2 m depth, at different topographic positions, at Cuieiras Biological Reserve, Manaus/ ZF2, km 34, in the Central Amazon, evaluating the soil attributes that may influence the permanence of soil carbon. Soil samples were collected along a transect of 850 m on topographic gradient Oxisol (plateau), Ultisol (slope) and Spodosol (valley). The stocks of soil carbon were obtained by multiplying the carbon content, soil bulk density and trickiness of soil layers. The watershed was delimited by using STRM and IKONOS images and the carbon contend obtained in the transects was extrapolated as a way to evaluate the potential for carbon stocks in an area of 2678.68 ha. The total SOC was greater in Oxisol followed by Spodosol and Ultisol. It was found direct correlations between the SOC and soil physical attributes. Among the clay soils (Oxisol and Ultisol), the largest stocks of carbon were observed in Oxisol at both the transect (90 to 175.5 Mg C ha-1) as the level of watershed (100.2 to 195.2 Mg C ha-1). The carbon stocks under sandy soil (Spodosol) was greater to clay soils along the transect (160-241 Mg C ha-1) and near them in the Watershed (96.90 to 146.01 Mg C ha-1).

Removal of organic matter and nutrients from slaughterhouse wastewater by using Eichhornia crassipes and evaluation of the generated biomass composting

The objective of this research was to evaluate the performance of the aquatic macrophyte Eichhornia crassipes applied in situ in a slaughter house treatment system, located in the west of the Paraná state, Brazil, regarding the nutrients removal and organic matter. Moreover, it aimed to obtain data from the production, management and composting practices of the biomass generated in the system. During 11 months of macrophytes development, physic and chemical parameters were monitored and plant density was controlled by periodical removal of excess biomass, which was weekly monitored and it is expressed in kg of aquatic plant per m² covered area. The degradation of the macrophytes removed from the treatment system was evaluated at the pilot scale in eight composting piles of 0.60 m³ that underwent four different treatments and two repetitions: T1 - water hyacinth (Eichhornia crassipes); T2 - water hyacinth and swine excrement (7:1), T3 - water hyacinth, swine excrement and earth (7:1:0,67), and T4 - water hyacinth, swine excrement and cellulosic gut (7:1:0,67), for a period of 90 days. The results indicated maximum removal efficiencies of 77.2% for COD; 77.8% for BOD, 87.9% for total nitrogen, 47.5% for ammonia nitrogen and 38.9% for total phosphorus for a five-day retention time. For biomass stabilization by composting, considering the C:N ratio as an indicator of compost maturity, it was observed that treatment T4 resulted in the shortest stabilization period (60 days). No difference was verified in the biostabilization rates at 5% level by the F test.

Recycling of nutrients with application of organic waste in degraded pasture

The utilization of organic wastes represents an alternative to recover degraded pasture. The experiment aimed to assess the changes caused by the provision of different organic waste (poultry litter, turkey litter and pig manure) in a medium-textured Oxisol in Brazilian Savanna under degraded pasture. It was applied different doses of waste compared to the use of mineral fertilizers and organic mineral and evaluated the effect on soil parameters (pH, organic matter, phosphorus and potassium) and leaf of Brachiariadecumbens (crude protein, phosphorus and dry mass production). It was observed that application of organic waste did not increase the level of soil organic matter and pH in the surface layer, and the application of turkey litter caused acidification at depths of 0.20-0.40 m and 0.40-0.60 m. There was an increase in P and K in the soil with the application of poultry litter and swine manure. All organic wastes increased the productivity of dry matter and crude protein and phosphorus. The recycling of nutrients via the application of organic waste allows efficiency of most parameters similar to those observed with the use of mineral sources, contributing to improving the nutritional status of soil-plantsystem.