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A escolha de um substrato que atenda às demandas nutricionais e físicas de mudas de mamoeiro com o uso de resíduos orgânicos, está diretamente ligada ao incremento da produção da cultura e se configura como uma importante alternativa ambiental e econômica. Com o intuito de produzir mudas de mamão de boa qualidade, levando em consideração a composição e a disponibilidade de substratos, objetivou-se avaliar a influência da aplicação de doses crescentes de biocarvão de cama de aviário como componente de substrato na produção de mudas de mamoeiro. O trabalho foi conduzido em ambiente protegido, pertencente a Universidade Federal de Campina Grande - UFCG. O delineamento estatístico utilizado foi o inteiramente casualizado em esquema fatorial 6 × 2, constituído de 6 doses de biocarvão (4, 8, 12, 16 e 20 t ha-1 e a testemunha) e duas variedades de mamoeiro (Formosa e Ouro) com 4 repetições. Foram avaliadas as variáveis altura da planta, diâmetro caulinar, número de folhas e área foliar aos 90 dias após o semeio. Também foram avaliadas as fitomassas fresca e seca da parte aérea e do sistema radicular e o Índice de Qualidade de Dickson. Conclui-se que as doses que proporcionaram um bom desenvolvimento das mudas de mamoeiro foram 8 e 16 t ha-1 e a variedade mamão Ouro apresentou os melhores resultados de crescimento.

Biocarvão da cama de aviário tem se mostrado promissor no desenvolvimento e produção de culturas. Dessa forma, o objetivo com esse trabalho foi o de avaliar a influência de doses crescentes de biocarvão de cama de aviário no crescimento e na produção do milho híbrido BRS 2022. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro repetições, sendo seis doses de biocarvão (0; 2,0; 4,0; 6,1; 8,1 e 10,1 t ha-1) e as parcelas constituídas por uma planta por vaso com volume de 20 dm3. Aos 83 dias após a semeadura do milho foram avaliadas as seguintes variáveis: alturas da planta e da inserção da primeira espiga, diâmetro do colmo, número de folhas, área foliar, comprimento e número de internódios, fitomassa seca de colmos, de folhas e total, massa de espiga, de grãos por planta e de 1000 grãos e comprimento e diâmetro de espigas. A aplicação do biocarvão influenciou na altura da planta e da inserção da primeira espiga, diâmetro do colmo, área foliar, comprimento de internódios, fitomassa seca de colmo, de folhas e total, refletindo positivamente no aumento das massas de espiga, de grãos por planta, de 1000 grãos, comprimento e diâmetro de espigas. Para as condições em que o experimento foi conduzido a dose de biocarvão recomendada para obtenção dos melhores resultados é de 6,4 t ha-1.

The dynamics of the organic residues added to the soil are closely related to its mineralization rate. Therefore, the present study aimed to evaluate the organic carbon mineralization in soil samples incubated with different doses of biochar and organic compost from poultry litter. Carbon mineralization was evaluated experimentally by measuring the C-CO2 liberated by incubating 200 g of soil mixed with different doses 0, 5, 10, 15, and 20 t ha-1 of both biochar and organic compost for 61 days. The soil microbial activity, and consequently the carbon mineralization, increased with the application of doses of biochar and organic compost from the poultry litter. The highest C-CO2 mineralization was observed in the treatments that received organic compost. The carbon mineralization process followed chemical kinetics with two simultaneous reactions. The greatest amount of released and accumulated C-CO2 was observed in the soil incubated with 15 and 20 t ha-1 of organic compost from the poultry litter. The doses of biochar did not influence the content of mineralized carbon; this behavior was not verified with the use of this compost, whose highest content corresponded to 85.69 mg kg-1, applying 20 t ha-1.

The objective of this work was to evaluate the effects of splitting in three different doses of phosphorus and potassium, combined with each other, and it was applied fertirrigation in watermelon crop, and to evaluate their effects on fruit quality. The statistical was in a complete randomized block design, and the treatments were arranged in a factorial scheme (3 x 3) in subdivided splits, resulting in 9 treatments with tree replications, totaling 27 plots in the experimental area. In the horizontal plots the three doses of phosphorus fertilization (100, 150 and 300 kg.ha-1 of P2O5) were randomly allocated, and in the subplots the three potassium doses (50, 100 and 200 kg.ha-1 of K2O), were applied in fertirrigation. The cultivar used was Crimson Sweet. Seventy-Six days after planting (DAP) the biochemical characteristics of watermelon fruits were evaluated: total soluble solids (TSS), total treatable acidity (TTA) and potential of hydrogen (pH). According to the results, it was verified that only the chemical value of the TSS fruits, presented significant statistical differences between the studied doses because of the different source of fertilization K and P increased the soluble solid contents, the content of reducing sugars, and decreased pH. It was observed the different doses of K and P did not influence in the fruit quality parameters when it was analyzed separated: TTA and pH but the TTA values are according to consumer market standards. The best doses in order to economy of fertilizer were (150 kg ha-1 de P2O5 e 50 kg ha-1 of K2O).

O girassol (Helianthus annuus L.) é uma espécie vegetal que apresenta inúmeras aplicações na atualidade, sendo considerada uma das plantas que apresenta um potencial máximo de sua produção. Objetivou-se com este trabalho avaliar aspectos fotossintéticos de cultivares de girassol, submetidas a diferentes regimes hídricos. O trabalho foi realizado em casa de vegetação, nas instalações pertencentes ao Departamento de Engenharia Agrícola da UFCG, conduzido em delineamento inteiramente casualizado em esquema fatorial 3 x 4 (três cultivares e quatro níveis de irrigação) com quatro repetições. Foram utilizados vasos com capacidade para 100 L, tendo-se o conteúdo de água do solo monitorado diariamente por meio de uma sonda de capacitância, modelo DIVINER 2000®, segmentada nos tratamentos com 100% da capacidade de campo (CC). Foram avaliadas as características: fluorescência da clorofila a, teores de clorofila a, b e total, e índice relativo SPAD. Houve diferença estatística entre as cultivares para o índice relativo de clorofila e o teor de carotenoides, e entre os regimes hídricos para os teores de clorofila b e clorofila total. Houve correlação entre o índice de clorofila (SPAD) e o teor de clorofila total. Os regimes hídricos não alteraram a fluorescência e o teor da clorofila a, entretanto, alteraram os teores de clorofila b e total em plantas de girassol.

O girassol é uma espécie vegetal com inúmeras aplicações, apresentando grande potencial para a produção de energia renovável. Apesar de existir informações na literatura, as necessidades hídricas e o comportamento de cultivares de girassol ainda não estão perfeitamente definidos, principalmente no Nordeste do Brasil. Objetivou‑se, assim, com este trabalho avaliar características do crescimento, desenvolvimento e produção de cultivares de girassol submetidas a diferentes regimes hídricos. O trabalho foi realizado em delineamento inteiramente casualizado em esquema fatorial 3 x 4, sendo três cultivares (BRS Gira 26, Agrobel 962 e Embrapa 122 V‑2000) e quatro níveis de irrigação (40, 60, 80 e 100% do conteúdo de água na capacidade de campo), com quatro repetições. Foram avaliadas as características: altura de plantas, diâmetro do caule, área foliar, início do florescimento, maturação fisiológica, fitomassa da parte aérea, número de aquênios e peso de aquênios. A reposição hídrica com 100% da água disponível apresentou maior altura de planta, diâmetro do caule, área foliar, fitomassa e, número e peso de aquênios, destacando‑se a Agrobel 962 para a maioraia das características. Lâminas de irrigação de 635,5; 603,7 e 546,2 mm, equivalentes a 100% da capacidade de campo, proporcionam melhores respostas de crescimento, desenvolvimento e produção das cultivares BRS Gira 26, Agrobel 962 e Embrapa 122 V‑2000, respectivamente.

A produção de flores e plantas ornamentais é uma atividade que já alcançou grande importância econômica em vários estados brasileiros, entretanto na Paraíba é pouco explorada, a qual se pretende potencializar com fertilização e manejo de água. O experimento foi desenvolvido em estufa, no Campus I da Universidade Federal de Campina Grande, Paraíba, com plantas de girassol cultivar Embrapa 122 V2000, avaliando os efeitos de nitrogênio, fósforo, potássio e conteúdo de água disponível no solo sobre a floração dessa oleaginosa. Utilizou-se o delineamento inteiramente ao acaso com onze tratamentos de adubação em matriz baconiana, com as doses de referência 60:80;80 kg ha-1 de N, P2O5 e K2O, respectivamente e quatro conteúdos de água disponível no solo (55, 70, 85 e 100 da AD) em triplicata. Foi avaliado o comprimento da haste, diâmetro externo e interno do capítulo e número de pétalas quando as inflorescências se encontravam totalmente abertas. Mesmo não afetando o número de pétalas, as maiores porcentagens de água disponível no solo promoveram melhor benefício à inflorescência do girassol. As doses de 60 kg ha-1 N; 80 kg ha-1 P2O5 e 80 kg ha-1 K2O proporcionaram melhor qualidade das inflorescências.

Entre as culturas utilizadas para a produção de biocombustíveis, o girassol é um das mais importantes. Apesar de existir informações na literatura, as necessidades hídricas e de nutrientes do girassol ainda não estão perfeitamente definidas. Com o objetivo de verificar os efeitos da adubação nitrogenada, fosfatada, potássica e o conteúdo de água disponível no solo (AD) sobre o comportamento vegetativo do girassol Embrapa 122 V2000, na Universidade Federal de Campina Grande, Campina Grande-PB, foi conduzido um experimento com quarenta e quatro tratamentos constituídos pela combinação de doses (kg ha-1 ) de N, P e K de acordo com uma matriz baconiana, sendo 1: 0-0-0, 2: 0-80-80, 3: 80-80-80, 4: 100-80-80, 5: 60-0-80, 6: 60-100-80, 7: 60-120-80, 8: 60-80-0, 9: 60-80-80, 10: 60-80-100, 11: 60-80-120 e quatro conteúdos de água disponível (55, 70, 85 e 100% da AD). O tratamento nove é o de referência, correspondendo às doses adotadas pelos produtores de girassol do Estado do Rio Grande do Norte. O delineamento foi inteiramente ao acaso em triplicata. Avaliou-se a altura de plantas, diâmetro do caule, número de folhas e área foliar, aos 40 e 60 dias após a semeadura. Os resultados indicaram que os efeitos da água disponível e adubação com NPK sobre a cultura do girassol ocorreram de forma independente, excetuando-se o número de folhas. Todas as variáveis apresentaram comportamento linear crescente em função da água disponível do solo, exceto a área foliar. Para as condições estudadas, as doses 100, 80 e 80 kg ha-1 de N, P2O5 e K2O, respectivamente, proporcionaram os maiores índices de crescimento.

Amburana cearensis (Allem.) A. C. Smith is a Brazilian semiarid region native plant. It presents good quality wood, contains an active ingredient that can be used for food, perfume and medicine production and it is also a forage and a melifera plant. The responses of the studied species to organic fertilizer and mulch, inputs produced and cycled within its ecosystem are still unknown. For this, an experiment was conducted to study the behavior of seedlings in an agroforestry system intercropped with maize and beans, testing different levels of organic matter (0, 15 and 30 L of manure) with and without soil mulch. It was evaluated the plant height, stem diameter, leaf number, leaf area and the survival of plants in the field one year after planting. The performance of A. cearensis was indifferent to the use of mulch and well adapted to low soil organic matter conditions, obtaining the largest growth in the absence of organic matter.

Considerando as potencialidades de uso do pinhão manso (Jatropha curcas L.) como fonte energética e a carência de resultados de pesquisa relativos ao seu cultivo foi desenvolvido na Universidade Federal de Campina Grande-PB, um trabalho comparando níveis de água residuária e adubação fosfatada na produção do pinhão manso sob ambiente protegido de casa de vegetação. O delineamento experimental foi realizado em blocos casualizados em esquema fatorial [4 x 5] + 1, cujos fatores foram quatro níveis de água residuária disponível no solo (50, 75, 100 e 125%) e cinco doses de fósforo (0, 100, 200, 300 e 400 mg/kg de solo) e uma testemunha absoluta com água de abastecimento 100% com adubação exclusiva só de N e K, com três repetições, perfazendo assim um total de 63 parcelas experimentais. Onde para o fator estudado teor de óleo do pinhão manso, apresentou resultados significativos em relação à aplicação de água residuária, rica em nutrientes essenciais para o crescimento e produção do pinhão manso.

O excesso de sais no solo causa prejuízos fisiológicos em vegetais como, redução da fotossíntese, transpiração e condutância estomática, comprometendo o desenvolvimento das culturas. Considerando a importância do feijão – caupi na dieta do nordestino, objetivou-se no presente estudo avaliar os parâmetros fisiológicos em feijão-caupi cv. BRS Pajeú sob diferentes níveis de salinidade da água de irrigação e doses de nitrogênio. O experimento foi conduzido em lisímetros de drenagem, no período de junho a setembro de 2013 em ambiente protegido. Utilizaram-se o delineamento experimental em blocos casualizados, em esquema fatorial (5 x 5), sendo cinco níveis de condutividade elétrica da água de irrigação - CEa (0,9; 1,8; 2,7; 3,6 e 4,5 dS m-1) e cinco doses de adubação nitrogenada (70; 100; 130; 160 e 190% da recomendação indicada para ensaios em vasos). Avaliaram-se a fotossíntese (A), transpiração (E), condutância estomática (gs), concentração interna de CO2 (Ci), eficiência instantânea da carboxilação (EICi) e eficiência intrínseca do uso da água (EUA). A adubação nitrogenada comportou-se de maneira semelhante nos diferentes níveis de salinidade da água utilizada na irrigação. Com exceção da concentração interna de CO2 as trocas gasosas reduziram-se linearmente com o aumento da condutividade elétrica da água de irrigação.

The aim of the present study was to evaluate water consumption, use efficiency and yield components of sunflower variety Embrapa 122 V/2000 cultivated in two types of soil (Fluvissol and Haplic Luvisol) subjected to increasing doses of cattle manure. The experiment was carried out in a greenhouse at Universidade Estadual da Paraíba. The experimental design was completely randomized in a factorial scheme. The irrigation was performed every other day, replacing the water absorbed by the plants. The water consumption and the use efficiency were evaluated, being the use efficiency determined by the ratio of the total dry mass of sunflower and the amount of water used to produce it in each treatment. Plants were harvested at 95 days after sowing when the following parameters were evaluated: number of seeds per plant, weight of seeds per plant, weight of 1000 seeds and the outer diameter of the capitulum (head). The results showed that the sunflower was positively affected by cattle manure application, increasing the production components and the water use efficiency, regardless of the type of soil. Excepting for the 1000 seeds weight and the water use efficiency, the type of soil affected significantly the water use, the number and weight of seeds per plant. The plants cultivated in Haplic Luvisol had a better performance.

Aiming to evaluate the effect of doses of bentonite (0, 30 and 60 t ha-1) in the mobility of cadmium on an Argisol, tests of mobility in soil columns with different cadmium concentrations (50, 250 and 450 mg kg-1 of soil) and steady state flux, were conducted, determining its flux density and percolation velocity. The cadmium was dislocated by pulse, the solution containing the cadmium initially infiltrated into the soil for a given time period and afterwards the soil was lixiviated with distilled water. Leachates were collected every 10 minutes during 80 minutes of water percolation. The solutions percolated, expressed in pore volumes, were 6.33, 2.28 and 1.93 for the 0, 30 and 60 t ha-1 of bentonite, respectively, being one pore volume equal to 1.22 cm3. The concentration of cadmium was measured by atomic absorption spectrophotometry. At the end of the experiment, the columns were dismounted and the concentrations of cadmium in the soil at different depths (0-10, 10-20, 20-30 e 30-40 cm) were also determined. The results showed that the flux density and velocity of water percolation of the water solution were significantly reduced by the addition of bentonite to the soil. The levels of cadmium in the soil did not affect these mobility parameters. Increasing doses of bentonite favored the adsorption of cadmium in the soil.

The aim of the present paper was to evaluate the Jathropa curcas L response to different doses of nitrogen, water regimes and soil surface nature. The experiment was conducted from May 2009 to February 2010 under greenhouse conditions at the Sustainable Development Center of the Federal University of Paraiba in Sumé-PB. A factorial experiment in blocks was used with four organic fertilizer (0, 50, 100 and 150 kg of N/ ha), four irrigation levels (50, 75, 100 and 125% the Class A pan evaporation) and four additional treatments with soil mulching. Sixty plastic vases 100 l capacity were used to cultivate the plants during 257 days and a Class A Evaporation Pan was installed in the greenhouse to monitor daily water evaporation. The plant variables evaluated were plant height, stem diameter, leaf area, total aerial and root dry mass. The increase of the soil water content and soil mulching had significant effect on the evaluated plant variables.

The actual paper was carried out aiming to evaluate the effects of nitrogen, phosphorus and potassium on the growth and seeds production of castor bean (Ricinus communis L.), cultivar BRS Nordestina and BRS Paraguaçu. For each cultivar an experiment was conducted in a greenhouse, in Campina Grande, PB. Each experiment was conducted on a 2 x 2 x 2 factorial design completely randomized resulting 24 experimental units, subjected to the following levels of fertilization: nitrogen (200 and 300 kg ha-1), phosphorus (150 and 250 kg ha-1) and potassium (150 and 250 kg ha-1). Plant height, stem diameter, number of leaves and leaf area were measured at 20, 40, 60, 80, 100, 120, 140 and 160 days after planting. At the end of the experiment the weight of seeds was measured. Nitrogen was the nutrient that promoted the highest growth and yield for both cultivars; the phosphorus and potassium application did not influence the stem diameter, leaf area and the yield of castor bean; the highest plant height was obtained with the treatment N1P1K1 (200-150-150 kg ha-1).

A adubação é uma importante prática para incrementar a produtividade das culturas. Assim, objetivou-se avaliar a fitomassa seca e os componentes da produção de mamona BRS Nordestina submetida à adubação mineral com nitrogênio, fósforo e potássio. O experimento foi conduzido em ambiente protegido com delineamento experimental inteiramente casualizado, constituído por oito tratamentos, correspondentes ao fatorial 2 (N1=200; N2= 300 kg ha-1) x 2 (P1=150; P2=250 kg ha-1) x 2 (K1=150; K2=250 kg ha-1), com três repetições, totalizando 24 unidades experimentais. Ao final do período experimental foram avaliadas a massa seca total da planta (raízes, caules, folhas e cachos) e os componentes da produção (número de frutos, peso sementes, número de sementes e peso do cacho por planta; peso de 100 sementes e comprimento do racemo primário). O tratamento 300: 250: 250 kg ha-1 de NPK foi o mais eficiente para os componentes da fitomassa seca da cultivar BRS Nordestina. Os tratamentos de fósforo e potássio não afetaram a fitomassa desta cultivar. Devido à falta de interação entre os nutrientes NPK, o maior rendimento de produção (peso de sementes por planta) foi obtido com a maior dose de nitrogênio e as menores de fósforo e potássio.

The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L.) clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC). The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L.) clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC). The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

Agriculture presents dependence on the climatic conditions, especially on precipitation. This way, it is necessary to study the probabilities of occurrence of rain in Garanhuns municipality, Pernambuco State, especially due to its irregularity, to support farmer’s decisions about agriculture activities. The objectives of this study were to forecast monthly rainfall at different significance levels and to determine the probabilities of occurrence of dry and rainy periods for Garanhuns region, state of Pernambuco, Brazil. Monthly rainfall data from 1913 to 1987 were analyzed. The criteria to identify dry and rainy periods were based on four classes of monthly rainfall: (S) dry month, from 0 to 50 mm; (PC) low rain month, from 50 to 100 mm; (C) rainy month, from 100 to 200 mm and (BC) very rainy month, above 200 mm. Thus, the monthly averages were analyzed according to the four classes of rains to estimate the probable occurrence of rain following Robertson (1976). The Gamma probability distribution was also used to forecast monthly precipitation, at the following levels: 90, 80, 75, 70, 60, 50, 40 and 30% of probability. The Gamma distribution adjusted well to the data of Garanhuns region, making possible the estimation of the probable rainfall amounts for each month of the year, at different levels of probability. Rainy season was the period between May and August, and the dry one between October and December. The lowest probable monthly rainfalls, below 50 mm, were observed between October and December, when irrigation is required for food production, being recommended to plant annual crops and cultivars of short cycle to be sowing in October, and of long cycle to be sowing in April, in order to reduce the risks of damage.

The Brazilian production of coconut has not been sufficient to attend the internal market demand which has resulted in great importations of dry and semi industrialized coconut (IBGE, 2006). The northeast of Brazil has the greatest coconut production and is, at the same time, characterized for its high evapotranspiration demand and the lowest precipitation, therefore, it is necessary to optimize the irrigation water used. During the development phase of the coconut tree, most of the root system concentrates around 1m of radius, and in the adult phase, in larger part, to a radius up to 2m. The traditional procedure of calculation of the water volume to be applied through irrigation, normally considers the area given by the crop planting spacing and a canopy cover coefficient. This results in great volumes of water applied unnecessarily. To save water, this study investigates the calculation of the volume of irrigation water considering the areas where larger concentration of the root system occurs. For the first year of development of the coconut tree, four areas of irrigation delimited by rings of zinc with diameters of 0.7 m, 0.8, 0.9 and 1.0 m were used to irrigate the portion with the larger concentration of the root system, and two conditions of soil covering (covered and bare soil), plus a control (4 x 2 + 1), resulting in nine treatments with three repetitions, totaling 27 plots. The procedure proposed in this research for the calculation of the water volume to be applied in the coconut crop, based on areas of larger concentration of the root system, promoted considerable economy of water, in relation to the procedure traditionally used. The isolation of the soil surface in order to avoid the evaporation contributed to a substantial reduction of the applied volume of water as well.

The lack of information on seedlings production mainly with respect to the use of residuary water for irrigation and soil subtracts and the sustainability aspect of the production justified the present study. The work was conducted on a greenhouse using the flamboyant (Delonix regia) a forestall specie widely used on reforestation. It was used a randomized block design with four subtracts: soil, soil + NPK, soil + organic compost and soil + biossolid , and two irrigation waters: normal and residuary water, arranged in a factorial form, totalizing fifty six experimental units in seven blocks. At the end of 100 days the plant variables were measured and the data analyzed statistically. Treatments and interactions affected the number of leaves, leaf area, plant height and the aerial plant weight, observing the best results when the residuary water was used for irrigation and when the plant was developed on the soil + organic compost and soil + biossolid subtracts. For the stem diameter and root weight just the subtract nature affected the seedlings, obtaining the best results on the soil + organic compost subtract. The root length was not affected by the treatments.

Considering the Sumé Irrigated Perimeter revitalization process the present work aims, throughout the soil chemical characterization of the area diagnostic the soil situation and offer subsidies to allow an adequate soil management. On the experimental area (33 plots totalizing 33 ha) soil samples were collected at 0-20 cm depth and characterized chemically. The obtained results were statistically using classical descriptive statistical techniques. With the exception of the organic matter, the others chemical properties are in adequate levels for the crop development. It is recommended, however, the incorporation of organic matter in the area soils. No salinity or sodicity hazards were founded in the analyzed soil samples. Different variation coefficients were observed on the analyzed chemical properties.

The Objective this work was to evaluate the interaction of the amount and salinity of irrigation water in the floral efficiency of the Green Dwarfish coconut tree, in the area of the coastal boards of the Northeast of Brazil. The study was driven in the experimental station of EMPARN, located in Parnamirim - RN, in the period of August of 2002 to September of 2003. The studied factors were four irrigation sheets, based on the evaporation of tank class "A" (30, 60, 90 and 120% of the evaporation of the tank) and four salinity levels in the irrigation water (0,1; 5,0; 10,0 and 15,0 dS.m-1). The experimental design was entirely random with subdivided portions and regression analysis with answer surface. The number of feminine flowers grows with the increment of the irrigation amount, reducing the negative effect of the applied saline levels. The relationship flower / picked fruit reduces with the increase of the saline levels, while the interaction of the largest irrigation sheets with the smallest saline levels results in a growth in the number of flowers emitted by picked fruits. The production in biomass of the fruits grows positively with the increase of the irrigation sheets and it reduces with the increase of the saline levels and the interaction of the smaller saline levels with the largest irrigation sheets produce the largest weights of registered fruits. As reaction the water with high salinity to the plant of the coconut tree answers with the increase of the efficiency of the bloomed related the crop of fruits, in other words, it emits less flowers to obtain the same production that in appropriate conditions of cultivation.

A condutividade hidráulica é o coeficiente de proporcionalidade da equação de Darcy e que, no solo, expressa a facilidade com que a água se transmite no perfil. A sua avaliação sob condições de não saturação é de fundamental importância na resolução de problemas práticos ligados ao uso e manejo da água, visto que, a maior parte dos processos que envolvem o movimento de água em condições de campo, ocorre quando o solo se encontra não saturado. A presença de camadas subsuperficiais no solo, fortemente adensadas, apresenta forte influência na condutividade hidráulica do solo e, consequentemente, na infiltração e condução de água no perfil. Visando identificar estas camadas, realizaram-se testes pelo método do perfil instantâneo em solos dos tabuleiros costeiros do distrito de irrigação de Platô de Neopolis-SE para determinar a condutividade hidráulica (K(θ)) em função da umidade do solo. Valores do potencial matricial e umidade volumétrica correspondentes foram obtidos a partir de tensiômetros instalados a seis diferentes profundidades. Os resultados comprovaram a adequação do método utilizado, com os valores obtidos de 12,0 cm.h-1 e de 2,0 cm.h-1 para o conteúdo de água do solo de 0,22 cm3.cm-3 para a primeira e segunda profundidade, respectivamente.

A utilização da matéria orgânica para germinação e produção de mudas de essências florestais é uma prática corriqueira, entretanto, as fontes e as dosagens adequadas a cada espécie ainda não estão esclarecidas. Visando dar alguma resposta a essas dúvidas um trabalho foi conduzido sob condições de viveiro para avaliar a germinação de cinco essências florestais (Cássia, Framboyant, Leucena, Sabiá e Tambor) semeados em substratos constituídos por dois solos de diferentes texturas (solo arenoso e solo argiloso) e diferentes doses de matéria orgânica (esterco de gado, esterco de galinha e esterco de minhoca). [..].

The objective of this work was to evaluate the residual nitrogen contents behavior in a soil fertilized with four different nitrogen sources (ammonium sulfate, calcium nitrate, urea and monoamonium phosphate) at dosage of 80 kg.ha-1, divided in 2, 3, 4 and 5 parcels, applied through drip irrigation on the melon production, in field conditions, at the Fazenda Cajazeiras, located in Tibau, RN, Brazil. A 4 x 4 factorial, completely randomized block split-plot design, with four replications was used. Soil samples were collected before planting and 40 days after the first nitrogen use to the depth intervals of 0-15, 15-30, 30-45 and 45-60 cm, on which total mineral nitrogen, NH4 +, NO3 - e NO2- was determined. A differentiated behavior of the nitrogen sources regarding the ammonium furnishing to the soil was observed, existing a decreasing tendency of the ammonium contents with the increase of the fertilization partitioning and soil depth. For nitrate the highest concentrations were found on the surface interval and no effect of the fertilizer partitioning was observed. The highest concentrations of nitrite were found on the 30 - 45 cm depth interval and the total mineral nitrogen was concentrated mainly on the root absorption region. The biggest accumulation of total mineral nitrogen in the soil was originated from employment of MAP and ammonium sulfate and the lesser accumulation was due to urea use.

The objective of this work was to evaluate the effect of four nitrogen sources (ammonium sulfate, calcium nitrate, urea and monoammonium phosphate) at 80 kg ha-1, applied 2, 3, 4 and 5 times through drip irrigation on the production and characteristics of the melon, under field conditions, at the Cajazeiras Agricultural Farm, located in Tibau, RN, Brazil. The experiment was carried out in a completely randomized block design, in a 4 x 4 factorial scheme, with four replications. The melon yield was measured considering total number and weight of the fruits, the number of marketable fruits per hectare and size of the fruits. Generally speaking, the results showed that melon plants presented similar response to all used nitrogen sources, notably to the MAP applied three times; that the number of nitrogen applications did not affected the evaluated parameters regarding production and quality of fruits; and that the used nitrogen sources and the application number of the fertilizers resulted in higher amount of types 6, 7 and 8 fruits (fruits with average size).

A treated sewage effluent was initially analyzed and after that an experiment was carried out to evaluate the effects of the irrigation using this effluent on some chemical properties of a Typic Quartzipsamment soil, in a greenhouse. The experiment was accomplished in a completely randomized design with two treatments and ten replications. The treatments consisted of applying normal water and treated sewage effluent in twenty experimental units (plastic bags with capacity of 2 L). Soil samples from experimental units, collected before and after experiment, tap water and treated sewage effluent samples were chemically analyzed. Results indicated that treated sewage effluent can be used for crop irrigation. When compared to water, irrigation with treated sewage effluent produced in the soil, under the study conditions: a) increase in the P and organicmatter contents in the soil; b) increase in the sodium contents, exchangeable sodium percentage and, consequently, in the soil pH; and c) increase on the sum of exchangeable basis and on the exchangeable cationic capacity.

Este trabalho foi desenvolvido em um solo aluvial na Estação Experimental da Embrapa Algodão, município de Souza, Estado da Paraíba, Brasil, com o objetivo de estudar a variabilidade espacial da densidade do solo. A área tem uma superfície cultivada de 17 ha e os testes de campo foram feitos em 40 pontos amostrais, locados na linha central longitudinal de cada parcela agrícola, eqüidistante de 50 m. Na determinação da densidade do solo, foi utilizado o método do anel volumétrico, em amostras com estrutura indeformada para as profundidades de 0-30, 30-60 e 60-90 cm. A variabilidade espacial foi determinada pela técnica de estatística clássica e da geoestatística. Na análise estatística clássica, a densidade do solo para as três profundidades apresentou baixos valores de desvio-padrão e coeficiente de variação, indicando pouca variação da densidade do solo com aumento da profundidade. A densidade do solo manifestou estrutura de dependência espacial, modelada por meio de semivariogramas, os quais permitiram a interpolação por "Krigagem", apresentando estrutura esférica nas profundidades de 0-30 e 60-90 cm, com alcance de 46 m e estrutura exponencial com alcance de 255,10 m para a profundidade 30-60 cm.This research was carried out aiming at studying soil density variability, in a soil alluvial Embrapa Algodão Experimental Station, Sousa, Paraíba, Brazil. The area has a cropped surface of 17 ha and field trials were done on 40 sampling points, placed on the central longitudinal line of each agricultural plot, distant 50 m. On the soil density determination the volumetric ring was used, in deformed structural samples for three depths: 0-30, 30-60, and 60-90 cm. Spatial variability was determined by classical statistics and geostatistics. In the classic statistical analysis of the soil density for the three depths presented standard deviation and variation coefficient low values, indicating low variation of the soil density with the increase of the depth. The of soil density manifested structure of spatial dependence, modeled through semivariograms, it was interpolated for "Kriging", the presenting spherical structure on 0-30 and 60-90 cm depth, reaching 46 m for both depths exponential structure reaching 255,10 m for 30-60 cm of depth.

Enfoca a problemática ambiental na caatinga, destacando o descaso para com este ambiente, que já se encontra fragilizado pela ação humana e discriminado inclusive pela legislação brasileira, que necessita ser atualizada e revista, requerendo também uma mudança de postura de cada cidadão, das empresas, organizações governamentais e não-governamentais. Traz alguns conceitos, legislação pertinente e informações que ajudam a compreender melhor a riqueza e o potencial de sustentabilidade do bioma.

O experimento foi conduzido visando avaliar a influência de diferentes substratos no desenvolvimento de mudas de cássia e de tamboril durante um período de 180 dias. O delineamento utilizado foi o inteiramente casualizado, com 7 tratamentos e 10 repetições para cada espécie, totalizando assim um experimento com 140 parcelas . As variáveis avaliadas foram a altura total das plantas, diâmetro do caule e massa seca da parte aérea. O desenvolvimento das mudas de cássia e de tamboril foi influenciado pelos diferentes substratos analisados. O melhor desempenho das mudas de cássia e tamboril foi observado quando se utilizou no substrato esterco de minhoca e de galinha, respectivamente.

O experimento foi conduzido visando avaliar a influência de diferentes substratos no desenvolvimento de mudas de leucena e de flamboyant durante um período de 180 dias. O delineamento utilizado foi o inteiramente casualizado, com 7 tratamentos e 10 repetições para cada espécie. As variáveis avaliadas foram altura total das plantas, diâmetro do caule e massa seca da parte aérea. O desenvolvimento das mudas de leucena e de flamboyant foi influenciado pelos diferentes substratos analisados. O melhor desempenho das mudas de leucena e flamboyant foi observado quando se utilizou como substrato esterco de bovino e de galinha, respectivamente. O esterco de minhoca proporcionou bons resultados somente para as mudas de leucena.