Navegando por Autor "Pessoa, Luiz Guilherme Medeiros"

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Condicionadores do solo como potencializadores do crescimento de forrageiras na agricultura biossalina
(2019) Leal, Larissa de Sá Gomes; Pessoa, Luiz Guilherme Medeiros; http://lattes.cnpq.br/1540664578909440; http://lattes.cnpq.br/8541410734100163
The secondary salinization, resulting from inadequate soil management practices has grown substantially in recent yearsamong soil degradation processes in Brazilian semiarid region. Its evolution, without intervention, tends to make agricultural production unviable, followed by desertification and abandonment of salinized areas. In view of its social, environmental and economic impacts, it is necessary to develop remediation techniques for such degraded soils. Thus, this work aimed to evaluate the performance of three forage species adapted to the semiarid and the potential of mixing soil conditioners, as a strategy for the use of degraded areas by salts. The experiment was conducted in a completely randomized design, in a 3x4 factorial arrangement and four replications, the first factor was the forage species and the second one were the soil conditioners mixture. For this, a Cambisol was used, classified as a saline-sodic soil. The soilsamplewas collected in the upper layer (0-20 cm), sieved and standardized, for assembly of the experiment and for chemical characterization. Then, it was packed in polyethylene vessels with 14 kg of soil, where they received the mixtures of soil conditioners: T1: control (without soil conditioner), T2: gypsum + organic matter, T3: elemental sulfur + organic matter, T4: gypsum + organic matter + elemental sulfur. One month after soil conditioners application, seedlings of sorghum, gliricidia and atriplex were transplanted. Irrigation was performed on alternate days, with an irrigation level equivalent to 40% of field capacity. The applied gypsum rate was 16.9 t ha-1, the sulfur was 3.97 tha-1and the organic matter was 30 t ha-1. At 60 days after transplanting the seedlings were collected and fractionated in roots, stems and leaves to obtain their fresh, dry and total weights; allocation of biomass, sodium, chloride and potassium in plant compartments; electrical conductivity of the saturation extract, pH, sodium and potassium content, and exchangeable sodium percentage in the soil after the experiment. Also the sodium absorption efficiency and transferwere determined. For the conditions of studied salinity, Atriplex is the most suitable for forage production and recovery of this soil. The conditioners did not influence the biomass production of the plants, however, their use associated to the halophyte cultivation contributed to the improvement of the chemical attributes of soil, promoting a greater reduction of the EC, ESP, and sodium, chlorine and potassium contentsof the soil, compared to the crop in their absence. The combination of gypsum + organic matter allowed greater accumulation of sodium, potassium and chlorine in the leaves, as well as a greaterreduction of EC and ESP. Therefore, for the production of forage and remediation of the area whose soil was collected for this research, it is recommended the use of Atriplex nummulariaassociated to the application of gypsum + organic matter to accelerate the remediation process.
Estado nutricional do Sorgo cv. Sudão e atributos do solo sob aplicação de atenuantes do estresse salino no semiárido de Pernambuco
(2023-04-27) Barros, Wanderson de; Pessoa, Luiz Guilherme Medeiros; http://lattes.cnpq.br/1540664578909440; http://lattes.cnpq.br/5782800123364087
O sorgo (Sorghum bicolor [L.] Moench), cv. Sudão é uma cultura em ascensão com diversos benefícios quanto a nutrição e adaptabilidade em condições de temperaturas elevadas, déficit hídrico e estresse salino. Em regiões semiáridas onde o solo apresenta diversos fatores limitantes como a salinidade, a cultura é capaz de obter pleno desenvolvimento. Desta forma, se faz necessário desenvolver mais pesquisas que otimizem o desenvolvimento do sorgo em regiões do semiárido. Neste trabalho, objetivou-se avaliar se o uso do Trichoderma (T) e a matéria orgânica (MO) potencializam a atuação do silício (Si) como atenuante ao estresse salino. A pesquisa foi conduzida em campo na Estação de Agricultura Irrigada de Parnamirim, pertencente à Universidade Federal Rural de Pernambuco – UFRPE. O delineamento experimental adotado foi em blocos casualizados, onde os tratamentos adotados foram: sorgo controle; Silício (Si); Silício + Matéria orgânica (Si + MO); Silício + Trichoderma (Si + T) e Silício + Trichoderma + Matéria orgânica (Si + T + MO). As variáveis avaliadas foram os elementos solúveis e trocáveis presentes no solo e na planta. Para o espaçamento foi utilizado 0,50 m entre fileiras e 10 plantas por metro linear, com dimensões de 330 m2 para área total, sendo 16 m2 por parcelas, e 4 m2 para as parcelas úteis para o experimento. Os dados obtidos foram submetidos aos testes de normalidade, análise de variância e as médias comparadas pelo teste de Tukey, ao nível de 5% de probabilidade. Onde foram observados que os tratamentos com silício combinado com matéria orgânica e Trichoderma foram significativos para atenuar os efeitos da salinidade no solo contribuindo com melhores condições para o desenvolvimento do sorgo cv. Sudão.
Modificação do uso da terra e seus impactos sobre o fósforo e carbono orgânico do solo no semiárido de Pernambuco
(2021-11-26) Silva, Luiz Filipe dos Santos; Pessoa, Luiz Guilherme Medeiros; http://lattes.cnpq.br/1540664578909440; http://lattes.cnpq.br/5391115086399833
In the Pajeú sertão, a semiarid region of Pernambuco, the deforested areas of caatinga are intensively used for agricultural cultivation until they deplete soil nutrients such as phosphorus and carbon. until exhausted, and after intensive use of the soil, these areas are abandoned and/or used for grazing animals. Thus, this work aimed to evaluate the dynamics of phosphorus and soil organic carbon under different conditions of land use, in the semiarid region of Pernambuco. Samples were taken in layers of 0-5, 5-10, 10-15 and 15-20 cm of soil under different land use situations: degraded pasture, regenerating caatinga and preserved caatinga. To characterize the chemical attributes of the soils, pH in water (1:2.5), exchangeable cations (Ca2+, Mg2+, Na+ and K+ ) were analyzed, in addition to available phosphorus and organic carbon. The evaluations showed a decrease in the phosphorus content of the surface layer, which was due to the processes of soil degradation generating a lack of nutrients, and the phosphorus content is being made available in the soil as there is a decrease in the levels of Na+ , Mg2+, pH and CTC. Therefore, the degradation of the area and land use without proper management provided an increase in Ca2+ and Mg2+, interfering with the availability of organic carbon, with a high CTC in the three areas. The pH and sodium showed a negative correlation, thus showing an increase in organic carbon as the area is preserved and a decrease with degradation. So, we warn that inadequate soil management can contribute to the loss of important nutrients to the soil such as phosphorus making it unavailable to plants and organic carbon, so it is important to emphasize that many years are needed for the recovery of phosphorus and organic carbon contents, this highlights the importance of preserving native vegetation in the semiarid region of Pernambuco and other northeastern states that belong to the caatinga biome.