CARACTERIZAÇÃO QUÍMICA DE DIFERENTES SISTEMAS DE USO DO SOLO

The form of management that is used in Amazonian soils determines its use in the future, so the chemical is critical, as is a parameter to indicate the fertility of these soils. The aim of this work was the chemical characterization of different land uses in the state of Pará were collected fifteen samples simple to form three composite samples with three replicates for each area in lowland soils, poultry and poultry in transition to floodplain with a wide range variation of chemical characteristics. Analyses were carried out in the department of soils in Universidade Federal Rural da Amazônia (UFRA). The following analyzes were performed: The pH, calcium, exchangeable magnesium, exchangeable aluminum and moisture content. Regarding pH, showed marked all soil acidity. As for humidity, lowland soil that was presented greater. For Ca2+ and Mg2+, the lowland soils that were also presented higher values??.   KEYWORDS: fertility, soil chemistry, soil management.A forma de manejo que se utiliza nos solos amazônicos determina a sua utilização no futuro, assim a caracterização química é fundamental, pois é parâmetro para indicar a fertilidade desses solos. O objetivo deste trabalho foi realizar a caracterização química de diferentes usos de solos no estado do Pará. Foram coletadas quinze amostras simples para formar três amostras compostas com três repetições para cada área nos solos de várzea, capoeira e capoeira em transição para várzea com ampla faixa de variação de características químicas. As análises foram realizadas no departamento de solos na Universidade Federal Rural da Amazônia (UFRA). Foram realizadas as seguintes análises: O pH em água, cálcio, magnésio trocáveis, alumínio trocável e umidade atual. Em relação ao pH, todos os solos apresentaram acidez acentuada. Já para umidade, o solo de várzea foi que apresentou valor mais elevado. Para Ca2+ e Mg2+, os solos de várzea também foram que apresentou valores mais elevados. PALAVRAS-CHAVE: fertilidade, manejo do solo, química do solo

CULTIVO DE TOMATE (Solanum lycopersicum) HIDROPÔNICO SOB DIFERENTES NÍVEIS DE FÓSFORO E POTÁSSIO EM SOLUÇÃO NUTRITIVA

Tomatoes are among the most consumed vegetables in the world, its annual production in Brazil is estimated at around four million tonnes. The objective was to study the effect of different doses of phosphorus and potassium on the growth of tomato grown hydroponically. The work was conducted in the greenhouse of the Institute of Agricultural Sciences, Federal Rural University of Amazonia, from October 2008 to January 2009, in nutrient solution. The experimental design was completely randomized factorial 3 x 3 (three doses of phosphorus and potassium three doses) with four replications. Each plot consisted of one plant per pot. There was no significant interaction for the factors evaluated. The treatments consisted of the combination P1K2 and P2K2 in better performance for plant height. For fresh weight of shoot and root fresh weight, P2K1 provided better growth compared to the other doses. In the total dry mass accumulation, the P1K1 and P2K1 treatments provided greater increments, 62.7 and 71.9 g plant-1 respectively. Based on this, the most effective treatment for the production of tomato was the P2K1, which promoted greater growth in all parameters evaluated.    KEYWORDS: Fertilizers, Soilless cultivation, Solanum lycopersicum.El tomate es uno de los vegetales más consumidos en el mundo, su producción anual en Brasil se estima en alrededor de cuatro millones de toneladas. El objetivo fue estudiar el efecto de diferentes dosis de fósforo y potasio en el crecimiento de plantas de tomate cultivadas hidropónicos. El trabajo se realizó en el invernadero del Instituto de Ciencias Agrícolas de la Universidad Federal Rural de la Amazonia, entre octubre de 2008 enero de 2009, en la solución nutritiva. El diseño experimental fue completamente al azar en el factorial 3 x 3 (tres dosis de fósforo y potasio tres dosis) con cuatro repeticiones. Cada parcela constaba de una planta por maceta. No hay interacción significativa de los factores evaluados. Los tratamientos consisten en una combinación P1K2 P2K2 y dieron como resultado un mejor rendimiento para la altura de la planta. Para peso fresco de brote y raíz peso fresco, P2K1 proporcionó mejor crecimiento en comparación con las otras dosis. En la acumulación total de masa seca, y los tratamientos P2K1 P1K1 ofrecido mayores incrementos de 62.7 y 71.9 g planta-1, respectivamente. Basado en esto, el tratamiento más eficaz para la producción de tomate fue la P2K1, que promovió mayor crecimiento en todos los parámetros evaluados.     PALABRAS CLAVE: Cultivo sin suelo, fertilizantes, Solanum lycopersicum.O tomate está entre as hortaliças mais consumidas no mundo, sua produção anual no Brasil é estimada em torno de quatro milhões de toneladas. O objetivo do trabalho foi estudar o efeito de diferentes doses de fósforo e potássio no crescimento de tomateiro, cultivado em sistema hidropônico. O trabalho foi conduzido em casa de vegetação do Instituto de Ciências Agrárias da Universidade Federal Rural da Amazônia, no período de outubro de 2008 a janeiro de 2009, em solução nutritiva. O delineamento experimental utilizado foi inteiramente casualizado em esquema fatorial 3 x 3 (três doses de fosfóro e três doses de potássio) com quatro repetições. Cada parcela foi constituída de uma planta por vaso. Não houve interação significativa para os fatores avaliados. Os tratamentos constituídos pela combinação P1K2 e P2K2 proporcionaram melhor desempenho para altura de planta. Para massa fresca da parte aérea e massa fresca de raiz, P2K1 proporcionou melhor incremento em relação às demais doses. Na massa seca total acumulada, os tratamentos P1K1 e P2K1 proporcionaram maiores incrementos, 62,7 e 71,9 g planta-1 respectivamente. Com base nisso, o tratamento mais eficiente para a produção do tomateiro foi o P2K1, que promoveu maior crescimento em todos os parâmetros avaliados. PALAVRAS-CHAVE: Cultivo sem solo, fertilizantes, Solanum lycopersicum

CRESCIMENTO E EFICIÊNCIA NUTRICIONAL DO NITROGÊNIO EM CULTIVARES DE MILHETO FORRAGEIRO NA AMAZÔNIA

The millet is a forage with high yield potential, mainly due to its high tolerance to water deficit and adaptation to soils of low fertility. Even being adapted to soils of low fertility, it is responsive to nitrogen fertilization. The objective was to evaluate the growth and nutritional efficiency of millet forage cultivars, due to nitrogen (N). The experiment was carried out in a greenhouse, in a typical Yellow Oxisol Dystrophic. The experimental design was a completely randomized design, arranged in a 4 x 2 factorial scheme with six repetitions. The factors were the control treatment (without fertilization with N) and three doses of N (75, 150 and 225 kg ha-1 ) in the form of urea and ammonium sulfate and two cultivars of pearl millet (BN2 and ADR500). The harvest was performed 80 days after the emergency. The higher production of dry matter of aerial part was obtained with the estimated dose of 179 kg ha-1 of N. The cultivar ADR500 showed the highest height and greater efficiency of translocation, while the BN2 showed higher N content of the aerial part and roots. The greater efficiency of use and translocation of N were achieved with doses estimated for 109 and 133 ha-1 of N for the cultivars ADR500 and BN2, respectively

ADUBAÇÃO POTÁSSICA EM HÍBRIDOS DE SORGO FORRAGEIRO CULTIVADOS EM SISTEMAS DE MANEJO DO SOLO NA AMAZÔNIA ORIENTAL

Sorghum is grown in areas and environmental situations very dry and/or too hot, where produc- tivity of other cereals is uneconomical. Aiming to evaluate the production of three sorghum hybrids, because of potassium and management systems, grown in Oxisol with low productive capacity, an experiment was con- ducted in the field, in the area of the Federal Rural University of Amazonia/UFRA, Belém campus The experi- mental design was randomized in blocks, arranged in a factorial 4 x 3 x 2 with four replications. The factors were: four doses of potassium (50, 100, 200 and 300 kg ha - 1 ) as KCl, three sorghum hybrids (Qualimax, Volumax and AG 2005 - E) and two tillage systems (no - till and conventional). The tillage produced a higher shoot dry weight of sorghum, and the hybrid and Volumax and Qualimax had incomes above the AG2005 - E. The contents of the elements N, P, K, Ca and Mg in the leaves of sorghum grown with tillage were higher than those found in conventional tillage. Doses of potassium resulted in greater increase in MSPA tillage using 40% less potash fertilizer with the conventional system

FOSFATO DE ARAD, NPK E CALAGEM NA CULTURA DO MILHO EM ÁREA DE PASTAGEM DEGRADADA

The establishment of pastures in Amazonia is made to replace the woody vegetation by slash and burn process in chemically poor and low available phosphorus soils. The recovery of degraded areas is required and can contribute to reducing deforestation in the region. This study aimed to evaluate the effects of doses of Arad and NPK combinations in the management of maize in soil with low productive capacity. The experiment was conducted in Santo Antonio do Taua, Pará State, in an area with degraded pasture, in a dys- trophic Oxisol. The experimental design was a randomized block split plot design with four replications. The plots were four phosphate: 50, 100, 200 and 300 kg ha-1 of P2O5 as Arad and sub-plots combination with NPK, NK, NK liming, and control ( no match ). We evaluated the growth characteristics and productivity of corn. Doses of Arad influenced the plant height and number of kernels per row cob. The application of Arad com- bined with NPK increased grain yield

Fosfato de Arad, NPK e calagem na cultura do milho em área de pastagem degradada

The establishment of pastures in Amazonia is made to replace the woody vegetation by slash and burn process in chemically poor and low available phosphorus soils. The recovery of degraded areas is required and can contribute to reducing deforestation in the region. This study aimed to evaluate the effects of doses of Arad and NPK combinations in the management of maize in soil with low productive capacity. The experiment was conducted in Santo Antonio do Taua, Para State, in an area with degraded pasture, in a dystrophic Oxisol. The experimental design was a randomized block split plot design with four replications. The plots were four phosphate: 50, 100, 200 and 300 kg ha(-1) of P2O5 as Arad and sub-plots combination with NPK, NK, NK liming, and control (no match ). We evaluated the growth characteristics and productivity of corn. Doses of Arad influenced the plant height and number of kernels per row cob. The application of Arad combined with NPK increased grain yield

SISTEMAS DE MANEJO E EFEITO RESIDUAL DO POTÁSSIO NA PRODUTIVIDADE E NUTRIÇÃO DO FEIJÃO-CAUPI

Cowpea [Vigna unguiculata (L) Walp] have great social and economic importance for the Para State. It grows well in areas with low precipitation and two crop cycles can be obtained annually. This study aimed to assess the effect of the residual fertilization from a previous culture (Sorghum bicolor L. Moench) and crop systems on cowpea yield and macronutrient concentration on leaves of three cowpea cultivars (BRS- Milênio, BRS-Urubuquara e BRS-Guariba). The study was conducted at the UFRA. The treatments were two crop systems (minimum tillage and conventional), four levels of potassium (50, 100, 200 e 300 kg de KCl ha-1 applied to a previous sorghum culture) and the three cowpea cultivars. Treatments were organized as a three (4 x 2 x 3) factor experiment on a randomized complete block design. The soil was a yellow latosol. In each ex- periment plot five plants were selected to determine shoot dry matter and foliar nutrient concentration. Grain yield was determined after harvesting all plants on the experiment plot. The residual KCl fertilization affected foliar nutrient content, but did not affect shoot dry mass or yield of grain. Yield was higher in the minimum tillage system. Highest yield (1590 kg ha-1) was recorded int the cv. ‘Guariba’ when 100 kg of KCl ha-1 had been used in the previous crop. The highest content of leaf N and K was found in cowpea under minimum till- age system. The amount of P and Mg were higher in the conventional system whereas the amount of Ca did not change

Sistemas de manejo e efeito residual do potássio na produtividade e nutrição do feijão-caupi

Cowpea [Vigna unguiculata (L) Walp] have great social and economic importance for the Para State. It grows well in areas with low precipitation and two crop cycles can be obtained annually. This study aimed to assess the effect of the residual fertilization from a previous culture (Sorghum bicolor L. Moench) and crop systems on cowpea yield and macronutrient concentration on leaves of three cowpea cultivars (BRSMilênio, BRS-Urubuquara e BRS-Guariba). The study was conducted at the UFRA. The treatments were two crop systems (minimum tillage and conventional), four levels of potassium (50, 100, 200 e 300 kg de KCl ha-1 applied to a previous sorghum culture) and the three cowpea cultivars. Treatments were organized as a three (4 x 2 x 3) factor experiment on a randomized complete block design. The soil was a yellow latosol. In each experiment plot five plants were selected to determine shoot dry matter and foliar nutrient concentration. Grain yield was determined after harvesting all plants on the experiment plot. The residual KCl fertilization affected foliar nutrient content, but did not affect shoot dry mass or yield of grain. Yield was higher in the minimum tillage system. Highest yield (1590 kg ha-1) was recorded int the cv. 'Guariba' when 100 kg of KCl ha-1 had been used in the previous crop. The highest content of leaf N and K was found in cowpea under minimum tillage system. The amount of P and Mg were higher in the conventional system whereas the amount of Ca did not change.O feijão-caupi [Vigna unguiculata (L) Walp] tem grande importância econômica e social no Estado do Pará. Devido a desenvolver-se bem em áreas com baixa precipitação pluvial e apresentar elevada eficiência nutricional, pode ser uma alternativa como cultura de segundo ciclo anual. O objetivo foi avaliar o efeito residual da adubação potássica, realizada na cultura de primeiro ciclo de cultivo sorgo (Sorghum bicolor L. Moench), e de sistemas de manejo sobre a produtividade de grãos e teores de macronutrientes em cultivares de feijão-caupi. O experimento foi realizado no campus da Universidade Federal Rural da Amazônia (UFRA) em Latossolo Amarelo distrófico. Utilizou-se um delineamento experimental em blocos casualizados, em esquema fatorial 2 x 4 x 3, com quatro repetições. Os fatores corresponderam aos sistemas de manejo (plantio direto e convencional), doses de KCl (50, 100, 200 e 300 kg ha-1) aplicadas no cultivo anterior (sorgo) e três cultivares de feijão caupi (BRS-Milênio, BRS-Urubuquara e BRS-Guariba). O cultivar BRS-Guariba foi o mais produtivo, atingindo uma produtividade de grãos de 1590 kg ha-1, com a dose de 100 kg de KCl ha-1. Maiores teores de N e K foram encontrados nas plantas cultivadas no sistema plantio direto, enquanto teores de P e Mg foram maiores no sistema de plantio convencional. Os teores de Ca não sofreram influências dos sistemas de manejo

Comportamento bioquímico no milho submetido ao déficit hídrico e a diferentes concentrações de silício

O milho é uma cultura que apresenta grande importância socioeconômica, no entanto, vêm sofrendo com estresse hidrico. O estresse é considerado um desvio significativo das condições excelentes para a vida. O silício (Si) é um elemento químico que atenua esse tipo de estresse na cultura, pois pode estimular o crescimento e a produção vegetal por meio de várias ações indiretas, e dessa forma propicia a proteção contra fatores abióticos, tais como estresse hídrico, toxidez de alumínio, ferro entre outros. O objetivo do trabalho foi avaliar a concentração de proteínas e aminoácidos no milho submetido ao déficit hídrico e a diferentes concentrações de Si. O experimento foi conduzido em casa de vegetação da Universidade Federal Rural da Amazônia, Campi de Capitão Poço, PA, Brasil. Foram utilizadas plantas de milho (Zea mays) variedade PZ 242. O delineamento experimental foi o inteiramente casualizado (DIC), no qual foram avaliadas duas condições hídricas: controle (sem Si) e déficit hídrico (com concentração de Si) com quatro concentrações de silício na forma de metasilicato de sódio (0.5, 1.0, 1.5 e 2.0 µM) com 7 repetições. As plantas tratadas com Si nas concentrações de 0,5µM e 1,5µM aumentaram a manutenção de água no tecido foliar. As concentrações de proteínas solúveis totais nas raízes e folhas de plantas de milho diminuíram significativamente quando foram submetidas à deficiência hídrica, enquanto as concentrações de aminoácidos solúveis totais nas raízes das plantas submetidas ao estresse S/Si, estresse 0,5µM e estresse 1,0µM aumentaram. Todavia, as concentrações de aminoácidos solúveis totais nas folhas aumentaram em todos os tratamentos. Além disso, o estresse hídrico afetou significativamente os processos bioquímicos nas plantas de milho

CRESCIMENTO, COMPOSIÇÃO MINERAL E SINTOMAS VISUAIS DE DEFICIÊNCIA NUTRICIONAL EM IPECA

The objective was to evaluate the effect of the omission of macronutrient and micronutrient boron in dry matter production, the characterization of the symptoms of nutritional deficiencies and mineral composition in plants of ipeca, an experiment was conducted in greenhouse conditions by the technique the missing element and visual diagnosis. A randomized block experimental design with four repetitions and the treatments were: complete and omissions of N, P, K, Ca, Mg, S and B. The analytical results demonstrated that the production of dry matter was affected in all of the treatments with omission of nutrients and that the ipeca plants presented characteristic symptoms of nutritional deficiencies due to the omissions of N, P, K, Ca, Mg, S and B and the concentrations of the macronutrients and of the micronutrient boron in the different parts of the ipeca plant varied when a certain nutrient was omitted in the solution