Alteração química do solo irrigado por aspersão e gotejamento subterrâneo e superficial com água residuária

Abstract

Propôs-se, neste trabalho, avaliar a variação dos constituintes químicos do solo devido à aplicação de água residuária e água de um depósito de fonte superficial, durante dois ciclos da alface (Lactuca sativa L.), cv "Elisa", utilizando-se os sistemas de irrigação por aspersão, gotejamento subterrâneo e superficial. Analisaram-se as camadas de solo de 0-0,10 e 0,10-0,20 m, aos 6, 26 e 46 dias após o transplantio no 1° ciclo e aos 7, 27 e 49 dias após o transplantio, no 2° ciclo. Os resultados demonstraram que no 1° ciclo a concentração de sódio apresentou elevação nos tratamentos irrigados com água residuária, em ambas as camadas de solo. As concentrações de manganês e cobre também indicaram elevação nesse ciclo, para a camada de solo de 0-0,10 m na irrigação por aspersão e gotejamento superficial com água residuária; no 2° ciclo os tratamentos irrigados com água residuária mostraram elevação do nitrogênio total em ambas as camadas de solo analisadas e da matéria orgânica, somente na camada de 0-0,10 m. Nesse ciclo, o manganês e o cobre também apresentaram redução na concentração, efeito atribuído às chuvas que ocorreram no período.

Changes in chemical attributes of a Fluvent cultivated with castor bean and irrigated with wastewater

“…These results corroborate with Leal et al (2009a) and Herpin et al (2007) information, who detected no changes in the magnesium levels between layers from 10 cm to 40 cm in sugarcane and coffee crops, respectively. Sandri et al (2009) found no differences between the Mg 2+ concentrations in the depth of 0-10 and 10-20 cm for lettuce cultivation.…”

“…Although castor beans can absorb significant amounts of Ca 2+ when grown in the presence of sewage sludge (Chiaradia et al, 2009), this nutrient is usually present in large amounts in wastewater from households, reaching in some cases concentrations higher than Na + , as observed in other studies (Medeiros et al, 2007;Sandri et al, 2009). These high levels in wastewater may lead to accumulation, even under crop cultivation , as found by Herpin et al (2007).…”

“…As there was no Mg 2+ absorption in T4, this cation tended to increase its soil concentration. Increments in Mg 2+ concentration due to the wastewater application were also observed by Sandri et al (2009). However, Kiziloglu et al (2008), Leal et al (2009a), and Varallo et al (2010) found no significant effect of wastewater irrigation on Mg 2+ content in soil.…”

“…In T1, despite receiving the same water as T4, the added Mg 2+ from the wastewater, usually present in low concentrations (Medeiros et al, 2007;Sandri et al, 2009;Leal et al, 2009a), was probably absorbed by the castor bean plants, since this nutrient is the 5 th most required nutrient for castor bean crop (Chiaradia et al, 2009). Supply water (T3) did not change the exchangeable magnesium neither calcium concentrations.…”

Root system distribution of sugarcane irrigated with domestic sewage effluent aplication by subsurface drip system

“…The use of sewage effluent in agricultural irrigation has been presented as a viable alternative for the disposal of wastewater, especially for its agronomic benefits, in which the water supply of vegetables and provision of essential nutrients for plant growth, appear as the main benefits the reuse (KALAVROUZIOTIS et al, 2009;FONSECA et al, 2007;SANDRI et al, 2009;DEON et al 2010, SANTOS et al, 2010.…”