Navegando por Assunto "Solos arenosos"

Agora exibindo 1 - 3 de 3

Aspectos ambientais dos tabuleiros costeiros entre Recife e João Pessoa
(1980) Falcão, Marlene Ferreira Lima; Lima, Clóvis Coêlho de Andrade
Os tabuleiros da costa oriental nordestina constituem uma feição morfológica como glacis de erosão e de acumulação da superfície geral da região. São superfícies planas ou ligeiramente onduladas, cortadas por vales fluviais, com altitudes variando entre 50 e 100 metros. Estendem-se sobre sedimentos cretáceos e terciários (glacis de erosão) e, em pequena parte sobre sedimentos quaternários (glacis de acumulação). Sua idade é quaternária inferior. Os solos destes tabuleiros são geralmente arenosos, latossolos pertencentes à unidade pedológica Utinga; eles suportam uma vegetação natural de florestas tropicais subperenifóleas, na sua maior parte destruída e substituída por cerrados.
Atributos físicos e químicos do solo cultivado com braquiária para implantação de plantio direto em São João - PE
(2019-07-18) Silva, Vanilson Pedro da; Lima, José Romualdo de Sousa; Rocha, Alexandre Tavares da; http://lattes.cnpq.br/4960111047922130; http://lattes.cnpq.br/3010818143250408; http://lattes.cnpq.br/4357896850368970
The Regolithic Neosols have predominance in the Agreste region of the municipality of São João, PE. The main crops of the region are beans and cassava, planted in the conventional planting system. The maize consortium with Brachiaria decumbens has shown promise in this region, but there are few studies on the use of this consortium for the formation of straw for implantation of the no-tillage system. The objective of this work was to determine the chemical and physical attributes of a typical Eutrophic Regolithic Neosol, of sandy texture, under plants and straw of B. decumbens Stapf. in the municipality of São João - PE, evaluating its influence as a cover plant on the quality of sandy soil. The treatments consisted of a single plantation system and a consortium of corn and millet with B. decumbens, distributed in randomized blocks in a 2x2 factorial scheme, with four replications. The planting was carried out in May 2017, remaining fallow after harvest for 18 months. The physical and chemical attributes were evaluated in the 0-10 cm and 10-20 cm layers, as well as the existing dry biomass. The dry biomass results obtained in the treatments with Brachiaria ranged from 10.37 to 13.06 Mg ha-1, being adequate for the implantation of the no-tillage system in the region.The treatments consorted with B. decumbens showed higher levels of total organic carbon and calcium. The treatments consorted with B. decumbens showed a trend of lower soil density, with higher total porosity and greater available water capacity. Considering the conditions of this work, intercropped corn crops are more productive and sustainable than traditional crop cultivation.
Calibração de sensores de umidade do solo de baixo custo
(2018-08-24) Oliveira, Cássio Lopes de; Lima, José Romualdo de Sousa; http://lattes.cnpq.br/3010818143250408; http://lattes.cnpq.br/2341449977247809
The monitoring of soil moisture is of extreme importance for the correct management of agricultural activities, such as irrigation. There are several methods to perform this monitoring: direct methods and indirect methods. These methods have advantages and disadvantages with respect to each other, for example, the direct (gravimetric) method, or standard method has the advantage of being a cheap method, however it has the disadvantage of being a destructive and slow method in the acquisition of the data. Indirect methods, which enable instantaneous and accurate readings, have the disadvantage of the high cost of purchasing such equipment. In this way, there is a need for a soil moisture monitoring system using low cost sensors and equipment, which can be accurate and read in a short period of time. Therefore, the present work had the objective of calibrating soil moisture sensors of low cost in soils of different textures. For this, soil samples were collected and submitted to particle size analysis. In order to obtain samples with different textures. A soil with high organic matter content and hydrophobic character were also used to evaluate the effect of hydrophobicity on the functioning of the sensors. After that, calibration tests were carried out on 06 units of low cost sensors model HL-69. The calibration tests consisted of determining the soil moisture directly (gravimetric method) and at the same time the sensors were read for different soil water contents. After the calibration tests, the data were tabulated and processed in electronic spreadsheets, where from the means of the readings of the 06 sensors, equations of adjustments were obtained for each type of soil. The percentage errors of each sensor were also calculated with respect to the mean of each sensor for each texture. It was observed that, independently of soil texture, the sensors presented a stabilization of the reading when submitted to humidity above the field capacity of each soil. It was also noted that for soils of the same texture and at the same moisture level, each sensor presented a different reading, indicating the need for individual calibration of the same. In relation to soil with a high content of organic matter (hydrophobic), it was verified that the sensor readings were different from the soils without this characteristic. Thus, it is concluded that low-cost sensors have good sensitivity within the range of available soil water, and can be used for irrigation management. However, they require specific calibrations for each type of soil and also for each sensor, this need increases even more when dealing with soils with high levels of organic matter.