To improve yield and nutrient absorption, the addition of fertilizers to provide nutrients in adequate quantities is recommended. An alternative substitution for soluble fertilizer is the use of Acidithiobacillus bacteria to produce rock biofertilizer that is then mixed with organic matter inoculated with diazotrophic bacteria (Beijerinckia indica) for N enrichment. This study evaluates the effectiveness of biofertilizer on nutrient uptake and its interaction with sugarcane filter cake in field-grown sugarcane on an Ultisol in the Brazilian rainforest region. The experiment used two NPK fertilizer treatments (biofertilizer and soluble fertilizer) applied at three rates (50, 100 and 150% of the recommended rate [RR]) and a control treatment of earthworm compost (20 t ha-1). The fertilizer treatments were applied with and without filter cake, in four replicates. Total C and N, available P and K, and exchangeable Ca and Mg in plants (upper shoots, leaves and stems) as well as soil samples were analyzed. The biofertilizer showed similar responses as did the soluble fertilizer in nutrient uptake in the different parts of sugarcane and in the soil samples. The effects of biofertilizer were enhanced by the interaction of the fertilizer treatments with sugarcane filter cake. We concluded that the biofertilizer enriched in N by inoculation with B. indica may be a viable alternative for the replacement of soluble fertilizers in sugarcane.

ABSTRACT The deployment of soluble fertilizers has been one of the most commonly applied agricultural practices in the bid to increase crop yield. However, the production of soluble fertilizers has a considerable economic cost and consumes a substantial amount of energy. In general, soil organic matter provides the nutrients needed for plant growth in organic agriculture. However, these nutrients are not sufficient if the best yield is to be obtained. The aim of our field experiment was to evaluate the effectiveness of phosphate and potassic sources (rocks, bio-fertilizers and soluble fertilizers) based on several sugarcane characteristics and soil attributes. Our experiment was conducted over two consecutive years, and we assessed the effect of using sugarcane filter mud cake (SFMC). In addition, we mixed the phosphate and potassic sources with earthworm compost enriched in N by inoculation with diazotrophic bacteria (OM) and applied at 50, 100 and 150 % of the recommended dosage rate (RDR). The PK biofertilizer with OM enriched in N positively affected sugarcane height, yield, and industrial characteristics. The application of SFMC greatly increased available P and K in the soil and plant characteristics with residual effect in the two consecutive harvests. We conclude that the biofertilizer has the potential to increase sugarcane characteristics and may represent an alternative to soluble fertilizers.

Solos salinos sódicos necessitam aplicação de condicionadores como gesso e matéria orgânica. Vários compostos foram avaliados como condicionadores para solos sódicos; entretanto, frequentemente estes materiais não promovem satisfatória redução no pH. Pesquisa recente demonstrou efeitos efetivos da aplicação da mistura de gesso e enxofre inoculado com Acidithiobacillus em solos sódicos com alto pH e sódio solúvel, todavia, os efeitos na planta não foram avaliados. O trabalho procurou verificar os efeitos de biofertilizantes de rochas (BPK), na nodulação, produção de biomassa e absorção de nutrientes em caupi comparado com fertilizantes minerais após adição dos condicionadores. Biofertilizantes (BPK) e fertilizantes minerais PK foram aplicados em diferentes doses, e as plantas inoculadas com rizóbios efetivos. Tratamento controle sem fertilização com PK foi incluído. Os resultados indicaram efeito do gesso e enxofre com Acidithiobacillus na redução do pH e sódio trocável. O biofertilizante de rochas (BPK) aumentou a nodulação, a biomassa e a absorção de nutrientes. Os rizóbios nativos do solo favoreceram o crescimento do caupi, apresentando resultados similares quando comparado com plantas inoculadas com rizóbios efetivos. O biofertilizante de rochas (BPK) mostrou ser alternativa para fertilizantes minerais com P e K em solos sódicos, após adição de gesso e enxofre inoculado com Acidithiobacillus.

Sodic soils require application of amendments as gypsum and organic matter. Many types of compost have been tested in sodic soils reclamation; however, these materials often do not provide satisfactory pH reduction. A recent study reported effective effects applying mixture of gypsum and sulfur inoculated with Acidithiobacillus in sodic soils with high pH and exchangeable sodium, though the effects on plant parameters were not evaluated. The present study was conducted to verify the effects of BPK rock biofertilizers on nodulation, biomass yield and nutrient uptake in cowpea compared with mineral fertilizer after sodic soil amendment. The BPK biofertilizers and PK mineral fertilizer were applied at different rates, and plants were inoculated with effective rhizobia strains. A control that did not receive PK fertilization was included. The results indicated that gypsum and sulfur with Acidithiobacillus reduced the soil's pH and the amount of soil exchangeable sodium. BPK rock biofertilizer increased cowpea nodulation, biomass yield and nutrient uptake. The native rhizobia in the soil exhibited effectiveness in cowpea growth; displaying similar results compared with the rhizobia inoculated plants. BPK biofertilizers may be used as alternative to mineral PK fertilizers in sodic soils after the application of gypsum and sulfur inoculated with Acidithiobacillus.

Pesquisas sobre a biodiversidade microbiológica de solos salinos envolvem a busca por genótipos tolerantes a esse tipo de estresse ambiental. Dados genotípicos correlacionados às características morfológicas, fisiológicas e bioquímicas de bactérias fornecem informações importantes para sua identificação e agrupamento. Este trabalho objetivou caracterizar rizóbios provenientes de solos salinos, do Agreste e Sertão de Pernambuco, utilizando jacatupé (Pachyrhizus erosus L. Urban) como planta-isca. Os testes foram efetuados em meio YMA e as características culturais observadas em 24 isolados foram as seguintes: mudança de pH, tempo de crescimento, transparência, forma, borda, produção de exopolissacarídeo das colônias e resistência à salinidade. Os testes moleculares utilizando análise por PCR (reação em cadeia da polimerase) por meio de seqüências repetitivas de DNA amplificadas com o primer BOX envolveram 13 isolados. Os resultados revelaram alta diversidade fenotípica e genotípica entre os isolados nativos. As características culturais e genéticas desses isolados foram comparados com 19 estirpes de referência. Os isolados NFB746 e NFB747 tiveram alta semelhança entre si e também com as estirpes Rhizobium sp. NGR234 (BR2406) e Mesorhizobium ciceri USDA3383 (BR521). O isolado NFB742, possivelmente, era da mesma espécie de M. ciceri (BR521). Com relação ao isolado NFB741, a semelhança com as bactérias Rhizobium tropici IIA CFN299T (BR10016) e Sinorhizobium terangue USDA4894 (BR527) foi de 87%. Os demais isolados, praticamente, formaram grupos independentes quando comparados com as estirpes de referência. Os resultados foram de grande relevância para diagnosticar novas espécies de rizóbios nativos altamente tolerantes a estresses ambientais.

Investigation on microbiological biodiversity in the saline soils involves searching for tolerant genotypes to this type of emvironmental stress. Genotypic data associated to morphologic, physiological and biochemical characteristics of bacteria provide important information regarding its identification and clusters. The objective of this work was to characterize indigenous rhizobial strains of saline soils in the Wasteland and Hinterland of Pernambuco State, using yam bean (Pachyrhizus erosus L. Urban) as plant-tramp. Assays had been performed in YMA media and the observed cultivation characteristics of twenty-four isolates had been: change of pH, time of growth, transparency, form, edge, production of exopolysaccharides of the colonies and resistance to salinity. DNA amplification by the PCR technique of the repetitive sequence BOX indicated a high level of genetic and fenotipic diversity between the thirteen indigenous isolates. Comparing cultivation and genetic characteristics of these isolates with nineteen reference strains, indicated that isolates NFB746 and NFB747 had presented high similarity between then and also with the Rhizobium sp. NGR234 (BR2406) and Mesorhizobium ciceri USDA3383 (BR521).The isolated NFB742 possibly belongs to of the same species of the M. ciceri BR521. In relation to the isolated NFB741, the similarity with the Rhizobium tropici IIA CFN299T (BR10016) and Sinorhizobium terangue USDA4894 (BR527) was of 87%. All others isolates had clustered in comparative independent groups when comared to reference lineages. These results are important for diagnosis of new species of native rhizobia in areas where the use of FBN can improve and rehabilitate saline soil using the rizobia-leguminous interaction.

A produção de biofertilizantes é um processo prático e econômico que reduz o consumo de energia e a sua aplicação visa aumentar o fósforo (P) disponível no solo. Biofertilizantes fosfatados (B5, B10, B15, B20) produzidos em laboratório usando fosfato natural (FN) e enxofre em diferentes concentrações (5; 10; 15 e 20%), inoculado com Acidithiobacillus (S*) e enxofre (20%) sem Acidithiobacillus (S), com incubação por 30, 45 e 60 dias, foi utilizado em um experimento em vasos com solo da Zona da Mata de Pernambuco (Argissolo Amarelo), com baixo nível de P disponível, cultivado com jacatupé (Pachyrhizus erosus), por dois períodos consecutivos. Os tratamentos fosfatados foram: fosfato natural (FN); biofertilizantes (B5, B10, B15, B20), com Acidithiobacillus (FN+S*) e B20, sem Acidithiobacillus (FN+S); superfosfato triplo (ST); e um controle sem fósforo (P0). As plantas foram inoculadas com a mistura das estirpes de rizóbio NFB 747 e 748, e sem inoculação. Nos ensaios em laboratório analisou-se o pH e o P extraído dos biofertilizantes, em cada período de incubação, e nos experimentos em vasos com solo determinou-se a biomassa seca, o N e o P total acumulado da parte aérea, o pH e o P extraído do solo. O P disponível foi mais elevado para os biofertilizantes com Acidithiobacillus (FN+S*) e para o superfosfato triplo. A fertilização fosfatada, condicionou resposta positiva dos biofertilizantes (FN+S*) e do superfosfato triplo. Os rizóbios nativos foram tão eficientes quanto os do inoculante. Após os dois cultivos o P disponível foi maior com os biofertilizantes B15 e B20 com Acidithiobacillus.

The production of mineral fertilizers is a expensive process, since it requires high energy consumption, and cannot be produced by small farmers. Laboratory assays were conducted to produce P-biofertilizers from natural phosphate (B5, B10, B15, B20), applying sulphur at different rates (5; 10; 15 and 20%) inoculated with Acidithiobacillus (S*) and testing increasing periods of incubation. A greenhouse experiment was carried out to evaluate the effect of the biofertilizers in a soil with low available P (Typic Fragiudult) from the "Zona da Mata" of Pernambuco State, grown with yam bean (Pachyrhizus erosus) in two consecutive harvests. The treatments were: Natural Phosphate (NP); biofertilizers produced in laboratory (B5, B10, B15, B20) with sulphur and Acidithiobacillus (NP+S*); natural phosphate with sulphur (20%) without Acidithiobacillus (NP+S); triple super phosphate (TSP) and a control without phosphorus. Plants were inoculated with a mixture of rhizobia strains (NFB 747 and NFB 748) or did not receive rhizobia inoculation. In bioassays pH and available P in the biofertilizers were analyzed. In the greenhouse experiment shoot dry matter, total N and total P in shoots, soil pH and available P were determined. Higher rates of available P were obtained in biofertilizers with sulphur and Acidithiobacillus (NP+S*) and in triple super phosphate (TSP), and biofertilizers with sulphur and Acidithiobacillus (FN+S*) and triple super phosphate (TSP) increased plant parameters. Native rhizobia were as effective as the strains applied in inoculation. After the two harvests soil presented lower pH values and higher rates of available P when the biofertilizers B15 and B20 with sulphur and Acidithiobacillus were applied.

Objective. To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Results. Capillary blood had higher Hb (+0.5g/dl) than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3g/dl). Specificity to detect anemia was adequate (>0.90) but sensitivity was low for capillary blood assessed by Hemocue (<0.80). Conclusions. The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies.

Objetivo. Evaluar la comparabilidad de la concentración de hemoglobina (Hb) en sangre venosa y capilar medida por Hemocue y por espectrofotómetro automatizado (Celldyn), así como documentar la influencia del tipo de sangre (capilar o venosa) y del método de análisis sobre la prevalencia de anemia. Material y métodos. De febrero a mayo de 2000, se recolectaron muestras de sangre capilar y venosa en 72 adultos y niños en el Hospital del Niño Morelense, Cuernavaca, Morelos, México. Se determinaron los niveles de Hb con los métodos Hemocue y Celldyn. Las cifras de Hb estimadas se compararon con el coeficiente de concordancia y la prueba pareada de t de Student. También se comparó la sensibilidad y especificidad para el diagnóstico de anemia, utilizando sangre de los dos tipos y métodos de análisis. Resultados. La Hb fue mayor en sangre capilar comparada con sangre venosa (+0.5g/dl) en adultos y niños, y en las determinaciones por Celldyn comparadas con las de Hemocue (+0.3 g/dl). La especificidad para el diagnóstico de anemia fue adecuada (>0.90), mientras que la sensibilidad fue baja para las muestras capilares medidas por Hemocue (<0.80). Conclusiones. Es probable que la diferencia en la Hb entre sangre venosa y capilar refleje variabilidad biológica. La Hb en sangre capilar medida por Hemocue provee una estimación adecuada de la prevalencia de anemia en poblaciones, pero podría resultar en un exceso de diagnósticos falsos negativos. Los resultados de este estudio ponen énfasis en la importancia de la técnica de recolección de la muestra, particularmente en niños. Los métodos de análisis y tipos de muestra de sangre deben ser tomados en cuenta en estudios de campo.

Objective. To assess the comparability of hemoglobin concentration (Hb) in venous and capillary blood measured by Hemocue and an automated spectrophotometer (Celldyn) and to document the influence of type of blood (capillary or venous) and analysis method on anemia prevalence estimates. Material and Methods. Between February and May 2000, capillary and venous samples were collected from 72 adults and children at Hospital del Niño Morelense (Morelos State Children's Hospital) in Cuernavaca, Morelos, Mexico, and assessed for Hb using the Hemocue and Celldyn methods. Estimated Hb levels were compared using the concordance correlation coefficient and Student's t test for paired data. The sensitivity and specificity for anemia diagnosis were estimated and compared between type of blood and method of assessment. Results. Capillary blood had higher Hb (+0.5g/dl) than venous blood in adults and children, as did samples assessed by Celldyn compared to Hemocue (+0.3g/dl). Specificity to detect anemia was adequate (>0.90) but sensitivity was low for capillary blood assessed by Hemocue (<0.80). Conclusions. The difference in Hb between venous and capillary blood is likely related to biological variability. Hemoglobin concentration in capillary blood assessed by Hemocue provides an adequate estimation of population anemia prevalence but may result in excess false negative diagnoses among individuals. The results of this study stress the importance of sample collection technique, particularly for children. Method of analysis and sampling site need to be taken into consideration in field studies.

Objetivo. Evaluar la comparabilidad de la concentración de hemoglobina (Hb) en sangre venosa y capilar medida por Hemocue y por espectrofotómetro automatizado (Celldyn), así como documentar la influencia del tipo de sangre (capilar o venosa) y del método de análisis sobre la prevalencia de anemia. Material y métodos. De febrero a mayo de 2000, se recolectaron muestras de sangre capilar y venosa en 72 adultos y niños en el Hospital del Niño Morelense, Cuernavaca, Morelos, México. Se determinaron los niveles de Hb con los métodos Hemocue y Celldyn. Las cifras de Hb estimadas se compararon con el coeficiente de concordancia y la prueba pareada de t de Student. También se comparó la sensibilidad y especificidad para el diagnóstico de anemia, utilizando sangre de los dos tipos y métodos de análisis. Resultados. La Hb fue mayor en sangre capilar comparada con sangre venosa (+0.5g/dl) en adultos y niños, y en las determinaciones por Celldyn comparadas con las de Hemocue (+0.3 g/dl). La especificidad para el diagnóstico de anemia fue adecuada (>0.90), mientras que la sensibilidad fue baja para las muestras capilares medidas por Hemocue (<0.80). Conclusiones. Es probable que la diferencia en la Hb entre sangre venosa y capilar refleje variabilidad biológica. La Hb en sangre capilar medida por Hemocue provee una estimación adecuada de la prevalencia de anemia en poblaciones, pero podría resultar en un exceso de diagnósticos falsos negativos. Los resultados de este estudio ponen énfasis en la importancia de la técnica de recolección de la muestra, particularmente en niños. Los métodos de análisis y tipos de muestra de sangre deben ser tomados en cuenta en estudios de campo.

Com o objetivo de avaliar o efeito da fertilização com fósforo, potássio e magnésio na fixação do N2 em jacatupé (Pachyrhizus erosus (L.) Urban) cultivado em um Latossolo Amarelo distrófico álico da Zona da Mata de Pernambuco, foi conduzido um experimento inoculando as sementes com a estirpe de Bradyrhizobium sp. NFB 450. Foram aplicadas quatro fórmulas de adubação com potássio e magnésio, na proporção (K2O:MgO) 2:1, em quantidades crescentes (0:0, 40:20, 60:30 e 80:40 kg ha-1 de K2O e MgO, respectivamente) e cinco níveis de fósforo (0, 20, 40, 60 e 80 kg ha-1 de P2O5, na forma de superfosfato triplo). A produção máxima foi obtida quando aplicou-se 64 kg ha-1 de P2O5. Observou-se efeito significativo para os níveis de K2O-MgO, quando em comparação com o tratamento sem K e Mg; entretanto, com o aumento da aplicação verificou-se diminuição da produção de matéria seca e do N total, e aumento do P total acumulado na parte aérea. O jacatupé respondeu a níveis baixos da fertilização com P, K e Mg, e mostrou-se efetivo na fixação do N2, com grande potencial na produção de biomassa.

In order to evaluate the effects of phosphorus, potassium and magnesium application on the nutrient absorption and yield of yam bean (Pachyrhizus erosus (L.) Urban), in a Yellow Latosol of the Zona da Mata of Pernambuco State, Brazil, an experiment was carried out using the strain of Bradyrhizobium sp. NFB 450, isolated from yam bean and selected for efficient N2 fixation in previous experiments. Potassium and magnesium were applied in the proportion of 2:1 (K2O:MgO) in increasing levels (0:0, 40:20, 60:30 and 80:40 kg ha-1 of K2O and MgO, respectively), and crescent levels of phosphorus (0, 20, 40, 60 and 80 kg ha-1 of P2O5) were added in the form of triple superphosphate. Maximum dry matter production, total N and total P accumulated were obtained when applying 64 kg ha-1 of P2O5. A significant effect of K2O:MgO levels was observed in relation to the treatment without K and Mg application; nevertheless, higher levels of K2O:MgO decreased dry matter and total N, and increased total P accumulation. Yam bean responded to low levels of P, K and Mg fertilizer, and showed ability in N2 fixation, with great potential for biomass production.