Lindbergue Araújo Crisóstomo

Crescimento e absorção de nutrientes por mudas de gravioleira

The objective of the research was to determine growth and nutrient absorption rates of soursop (Annona muricata L.) during seedling phases. Seeds of soursop after germination were transferred to polyethylene bags filled with 5 dm3 of a 3:1 (v/v) mixture of surface soil:organic mineral soil. Fifteen days after seedling transplanting and each fifteen days intervals up to 195 days, five seedlings were randomized taken for height, stem diameter and nutrient absorption evaluation. Seedlings growth was initially slow up to 105 days, and only 27% of dry matter were produced. Mineral nutrient absorption increased with plant age and 67% was accumulated from 105 to 195 days period in the following order K>N>Ca>Mg>P and Fe>Zn>Mn>Cu.

Inoculação de fungos micorrízicos arbusculares e adubação fosfatada em mudas de cajueiro-anão-precoce

This work aimed to evaluate the effects of the inoculation of native and exotic arbuscular micorrhizal fungi (AMF) and of the phosphate fertilization on plant growth and nutrient accumulation in dwarf cashew CCP 76. A greenhouse experiment, using a factorial arrangement (4x2), with three mixtures (two native communities of AMF and the commercial Mycogold product) besides a control without fungi and two dosages of phosphorus (0 and 87 mg/L) was carried out. Native AMF were represented by the species Glomus etunicatum, G. glomerulatum, Scutellospora sp. and Acaulospora foveata, from the first community, and G. etunicatum, Entrophospora sp. and Scutellospora sp., from the second community. The cashew seedlings presented a low response to the phosphorus treatment. The symbiotic plant association with the native fungi of the first community and exotic fungi of the commercial product allowed a better plant growth four months after cashew nut sown.

A new proposal of the classification of irrigation water.

A study on surface water quality in the Acarau Basin, in the North of the state of Ceara, Brazil was performed. Qualitative dynamics of water flowing to the Acarau River that supplies water to the irrigation project in the area was evaluated. Multivariate Factor Analysis/Principal Component Analysis was used for evaluation of water quality in order to develop a water quality index (WQI) that reflects soil salinity and sodicity risks and water toxicity to plants. From April/2003 to September/2005 water were sampled from ten sampling sites covering the basin, where physical and chemical parameters that contribute to the WQI were evaluated. The results showed that the use of water for irrigation in the Acarau basin, according to the proposed WQI, are potentially prone to cause toxicity (crop cycle) and sodicity problem in the long run, if the soil-water-plant is not carefully monitored.

Impacto da lixiviação de nitrato e cloreto no lençol freático sob condições de cultivo irrigado

Environmental impacts of nitrogenous fertilizers, pesticides and salts contained in irrigation are becoming an increasing concern, because they may move with soil water from root zone to groundwater. The aim of this research was to identify the irrigation management and the rainfall depth influence over nitrate and chloride concentration in the soil profiles, as well as the risk of water table pollution in the Irrigated District of Baixo Acarau (DIBAU), Ceara, Brazil. Soil samples were taken each 50cm deep soil profiles until to saturated zone (7m) in two different types of land use: irrigated area (S1) and native area (S2). Samples occurred during irrigation activities (Nov/06) and rainfall season (May/07). The water table was measured, monthly, from Dec/2003 to Nov/2005, Nov/2006, Mar and April/2007 in four shallow wells, two located in irrigated fields and the others in native. The greatest chloride concentration in the soil profiles was registered during rainfall season, suggesting the effect of sea-salt aerosols influence on chloride soil content. The greatest nitrate concentration occurred under irrigation period. Also, the results show that irrigation caused the groundwater concentration of NO3-N to increase from 1.52 to 19.3mgL-1, thereby, exceeding the standards on Regulation MS number 518/2004 and 357/2005 Resolution.

Efeito da bactéria diazotrófica em mudas micropropagadas de abacaxizeiros Cayenne Champac em diferentes substratos

Abstract – The objective of this work was to evaluate the effect of a diazotrophic bacteria isolated frompineapple ( Ananas comosus ) plants on plantlets growth and nutrient accumulation of the cultivarCayenne Champac grown with different substrates in tubules conditions. Treatments consisted of sixsubstrates: carbonized rice hulls + leave dust from carnauba ( Copernicia cerifera ) palm tree +vermicompost; carbonized rice hulls + rip coir dust + vermicompost; carbonized rice hulls + vermiculite +vermicompost; carbonized rice hulls + leave dust from carnauba palm tree + vermiculite; carbonizedrice hulls + ripe coir dust; and carbonized rice hulls + vermiculite. The bacterium isolate was identifiedby similarity (97% to 98%) of sequences of 16S rDNA with the species Asaia bogorensis. After thebacterial inoculation , plants were transferred to substrates into tubules conditions. After four months,at harvesting, acclimated plants were ready to be planted in the field. The occurrence of diazotrophicbacteria related to

Carbon and nitrogen stocks of an Arenosol under irrigated fruit orchards in semiarid Brazil

O acumulo de materia orgânica beneficia a produtividade do solo e reduz a concentracao do carbono atmosferico. Entretanto, pouco e sabido a respeito do acumulo de C e N em solos arenosos cultivados com culturas perenes irrigadas em regioes semi-aridas. O objetivo deste trabalho foi avaliar o efeito do cultivo de fruteiras irrigadas nos estoques de C e N de um Neossolo Quartzarenico em Paraipaba, CE. Foram coletadas amostras na linha e na entrelinha de pomares irrigados de banana, caju, manga, sapoti, goiaba e graviola. Em areas adjacentes sob vegetacao de Caatinga hipoxerofila e apos dois anos de desmatamento foram coletadas amostras adicionais. As profundidades de amostragem foram: 0 a 0.1, 0.1 a 0.2 e 0.2 a 0.4 m. Os teores de C e N no solo foram mais altos na camada superficial (0 a 0.1 m). Nao houve efeito da profundidade de amostragem sobre a densidade do solo. Os estoques de C e N na area com vegetacao de Caatinga na camada de 0 a 0.4 m foram de 27,6 and 2,4 Mg ha-1, respectivamente. A retirada da vegetacao natural e o cultivo das fruteiras levaram a reducoes de 5 a 23% e 4 a 21% nos estoques de C e N do solo, respectivamente. As culturas do sapoti e da graviola contribuiram para o aumento dos estoques de C e N apos a retirada da vegetacao natural. As culturas da goiaba, graviola, manga e sapoti contribuiram para a melhoria do indice de estratificacao deste solo.

Linha de fronteira e chance matemática na determinação do estado nutricional de pitaia

Com o presente trabalho objetivou-se avaliar, atraves dos metodos linha de fronteira e chance matematica, o estado nutricional de pitaias submetidas a combinacoes de doses crescentes de nitrogenio-potassio (N-K) e fosforo-zinco (P-Zn). Foram aplicadas cinco doses de N (0; 150; 300; 450 e 600 mg dm-3) e K (0; 75; 150; 225 e 300 mg dm-3) no experimento I, e cinco doses de P (0; 75; 150; 255 e 300 mg dm-3) e Zn (0; 2; 4; 6 e 8 mg dm-3) no experimento II. Ambos os experimentos foram arranjados em esquema fatorial 5 x 5, com quatro blocos ao acaso. Houve bastante similaridade entre as faixas de suficiencia obtidas pela chance matematica e linha de fronteira, exceto para o fosforo. As faixas de suficiencia obtidas pela linha de fronteira foram mais amplas que as obtidas pela chance matematica. O metodo linha de fronteira apresenta elevada capacidade preditiva no ajuste dos dados, demonstrando ser uma importante ferramenta na obtencao de faixas de suficiencia e valores de referencia para estudos posteriores de diagnose nutricional em pitaia.

Produced water irrigation changes the soil mesofauna community in a semiarid agroecosystem

The scarcity of water in semiarid regions requires alternative sources for irrigation to improve agricultural production. Here, we aimed to evaluate the effects of produced water from oil exploration on the structure of soil mesofauna during the dry and rainy seasons in irrigated sunflower and castor bean fields in a Brazilian semiarid region. Three irrigation treatments were applied on plots cultivated with castor beans and sunflowers: produced water treated by filtration (filtrated) or treated by reverse osmosis (reverse osmosis) and groundwater. The mesofauna under the biofuel crops was collected and identified during the dry and rainy seasons. Although the abundance and richness of the total fauna did not differ between seasons in sunflower plots, the community was altered. In castor beans, the abundance, richness, and community of mesofauna observed in plots irrigated with produced water differed from the groundwater treatment. Irrigation with produced water promotes important changes in soil fauna community that justify their assessment for the maintenance and monitoring of agroecosystems.

Dinâmica do nitrato e cloreto no solo e a qualidade das águas subterrâneas do distrito de irrigação Baixo Acaraú, CE

This work was developed aiming to investigate how water in irrigation systems alters the dynamics of chloride and nitrate in the soil profile and its impacts on the ground water of the irrigation district Baixo Acarau DIBAU, Ceara, Brazil. In investigating the dynamics of ions and moisture in the soil profile, samples were collected every 50 cm depth from the surface to the area of the capillary fringe of the watertable. Samples were collected during the rainy season (May/11) and dry (Sep/11) in both areas: A1 and A2. To identify the concentration of ions in the water table, monitoring was done monthly for 12 months (to Aug/10 Jul/11) in two wells inserted in irrigated fields and two in uncultivated areas. To assess whether variations in the gravimetric moisture content and the content of Cland NO3 in soil showed significant differences between the rainy and dry periods, we used the Student t test at 5%. The chloride content of the soil profile of irrigated area (A1), 62% were higher than those recorded in the uncultivated area (A2) in both seasons. The increase of nitrate in the wells of the irrigated area is worrying as these in certain months of the year (Nov/10) and (Mar/11 to June/11) significantly exceeded the maximum acceptable for human consumption by Ordinance No 518/2004 the Ministry of Health and Resolution 357/05 CONAMA.

Produção de serapilheira e ciclagem de nutrientes na cultura do cajueiro anão precoce

This study aimed to (a) to evaluate the biomass production from the crown of the young dwarf cashew, clone CCP 76, at 2, 3, 8 and 9 years of culture implantation, (b) to determine the rate of leaf decomposition and (c) to quantify nutrient contribution potentially available in the biomass to be recycled into the soil. The research was conducted at the Experimental Field of Curu, in Paraipaba - CE, from December, 2003 to January, 2005. The treatments consisted of orchards with trees of 2, 3, 8 and 9 years of plantation, distributed in a completely randomized design with eight replications. Litter was collected using 1 m2 collectors with 1 mm2 mesh place 40 cm above the soil surface. After sampling, the material was sorted out into portions of leaves, branches, inflorescence, peduncle and nut, oven dried and weighed. In the leaf portion, the compositions of N, P, K, Ca, Mg, S, Na, Cu, Fe, Mn and Zn were determined. Leaves ready to fall were collected from each plant to determine their decomposition rate and 12 g of this material was stove dried, and placed in 20 cm x 20 cm nylon bags and 2 mm mesh which were distributed on the soil surface and collected after 112, 233 and 369 days. In each collection, the material was oven dried and the remaining nutrient biomass (N, P, K, Ca, Mg, S, Na, Cu, Fe, Mn and Zn) was determined. The 8- and 9- year- old plants deposited greater quantities of litter during the experimental period and showed greater potential for nutrient recycling. During the experimental period it was generally observed that the decomposition process was fast in the first four months, remaining slow until the end of the observation period. Most of the nutrients in the cashew tree were released in the first four months of leaf composition.