Effects of composted urban solid waste addition on yield and metal contents of lettuce

Abstract

Foi desenvolvido um estudo para avaliar a acumulação de Cu, Mn, Ni, Pb e Zn, em alface cultivada em Latossolo, ao qual foram adicionados compostos de resíduos sólidos urbanos provindos de uma grande cidade (Rio de Janeiro, Estado do Rio de Janeiro) e de uma pequena cidade (Coimbra, Estado de Minas Gerais). As amostras de composto foram aplicadas ao solo em doses crescentes e em diferentes tempos de contato entre o composto e o solo. Foi avaliada ainda a influência dos metais na produção de matéria fresca e seca de folhas da alface. A produção de alface aumentou com a elevação das doses dos compostos, sendo a produção máxima obtida entre 15 e 20 dias. As concentrações de metais nas folhas aumentaram com o acréscimo da dose de composto e com o tempo de contacto entre o composto e o solo, porém não atingiram os limites máximos permitidos pela Legislação Brasileira para alimentos. A aplicação do composto de Coimbra promoveu maior produção e concentrações menores dos metais na planta, em relação ao composto do Rio de Janeiro.A study was performed to evaluate Cu, Mn, Ni, Pb, Ni and Zn accumulations in lettuce grown in an oxisol amended with composted urban solid wastes collected in Brazil from a big city (Rio de Janeiro, Rio de Janeiro State) and from a small city (Coimbra, Minas Gerais State). The compost samples were applied to the soil at increasing doses and different times of contact between compost and soil. The influence of the metals on the fresh and dry matter yield of leaves was also examined. Lettuce yield enhanced when the doses of the composts were increased and maximum yield was achieved in the cropping time between 15 and 20 days. The metal concentrations in the leaves augmented with the increase of the applied compost and with the increase of the time of contact between compost and soil. However, metal concentrations in the plant were below the maximum limits allowable by the food Brazilian legislation. The application of the compost from the smaller city resulted in increased lettuce productivity and lowest metal concentrations in the plants as compared to the results of the application of the compost from the bigger city.

Evaluating the influence of enriched urban compost and wastes on plant nutrient uptake

“…However, numerically higher uptake was recorded with 75% NPK +7.5 t ha -1 microbial enriched SS (T 8 : 30.56 g ha -1 and 87.32g ha -1 , respectively) over the absolute control with (T 1 : 11.34 g ha -1 and 23.10 g ha -1 ), respectively. Jordao et al (2007) [8] reported higher Ni uptake in plants with the increased dose of urban compost. The uptake of lead by both kernel and stover of maize was found to be statistically non-significant.…”

Copper, nickel and zinc accumulations in lettuce grown in soil amended with contaminated cattle manure vermicompost after sequential cultivations

“…In addition, two applications of 0.24 g of (NH 4 ) 2 SO 4 and 0.09 g of KCl per pot were made on the 20th and 30th days after transplanting. Twenty days after the transplanting, 10 were macerated. The roots provided only sufficient material for the determination of the metal concentrations in the total mass of each plant.…”