Role of Organic Fertilizer in the Transfer of Lead to Vegetables Produced in Tropical Mountain Agroecosystems.

Understanding the relationship between the aerobic transformation of organic matter (OM) and the bioavailability of lead to plants may allow the safe application of organic fertilizers (OF) in agriculture. The present study aimed to elucidate the relationship of different OM structures with Pb, revealing the action of OF (poultry litter) on Pb dynamics, presenting the effects of OM transformations on bioavailability and transfer to vegetables produced in tropical mountain agroecosystems (TMA). The association of Pb with hydrophilic structures (CAlk-O and CAlk-di-O) during the aerobic transformation of poultry litter (PL) contributes to the increase in the water-soluble form of this metal (3.

Spatial distribution and factors influencing the accumulation of toxic metals in soils in mountain agroecosystems, Rio De Janeiro, Brazil.

The concentrations of toxic metals (TM) were analyzed in 498 samples of agricultural soils used for intensive vegetable cultivation in the watershed of Barracão dos Mendes, Brazil. The goal of this study was to characterize the distribution of these elements and the main natural and anthropogenic factors affecting their accumulation. In general, the average concentrations of TM were higher than the reference quality values for cultivated soils in the region, with the exception of Cr, Co, Ni and Mn, and the average concentration of Cd was ten times greater.

Cadmium and lead transfer factors to kale plants (Brassica oleracea var. acephala) grown in mountain agroecosystem and its risk to human health.

The aim of the present study is to assess soil Cd and Pb contamination in kale (Brassica oleracea var. acephala) production sites in mountain agroecosystem, as well as its potential risk to human health. The study was carried out within 24 kale-production sites located in mountainous region of Rio de Janeiro (Brazil).

Influence of humic acid structure on the accumulation of oxyfluorfen in tropical soils of mountain agroecosystems.

Herbicide application is a practice commonly used in agricultural systems because it is an efficient method of weed control. An inherent characteristic of some herbicides used in mountain agriculture, such as oxyfluorfen, is high adsorption to soil organic matter (SOM). Thus, intensive management that changes the quantity and quality of SOM, such as soil tillage and the massive application of organic fertilizers such as poultry litter, may favor soil contamination by this herbicide and alter its dynamics in the environment.

Variability factors of heavy metals in soils and transfer to pasture plants of Mayabeque in Cuba.

Studies to assess variability factors of heavy metals in soils are essential to understand their behavior in the environment and for the assessment of contaminated areas. In this context, this research aimed to study the factors that influence the variability of heavy metal levels and their bioavailability in pasture areas in the Alturas de Nazareno region, Mayabeque, Cuba, as well as the transfer to plants. Forty-five points were distributed in a natural pasture and at two depths (0-20 and 20-40 cm) as a function of relief and soil type.

Humic acids induce a eustress state via photosynthesis and nitrogen metabolism leading to a root growth improvement in rice plants.

Chemical eustressors induce a eustress state "positive stress" increasing the resistance and improve the plant growth. The potentiality of humic acids (HA) to act as a eustressor has been scarcely explored. The present study aims to evaluate how HA with different structural characteristics induce differently, a eustress state in rice plants through the regulation of photosynthesis.

Lead and Cadmium Transfer Factors and the Contamination of Tomato Fruits (Solanum lycopersicum) in a Tropical Mountain Agroecosystem.

The objectives of this study was to diagnose Cd and Pb contamination in soil and to identify the main factors that contribute to the transfer of these elements to tomato plants and fruits and contamination levels of the fruits in tropical mountain conditions. Contamination of the study area soils by Cd and Pb was verified. This contamination stemmed from the intensive use of agricultural inputs, mainly organic fertilizers and soluble mineral fertilizers.

Limited Diclosulam Herbicide Uptake and Translocation-Induced Tolerance in Crotalaria juncea.

The study was to identify the potential tolerance of Crotalaria juncea to diclosulam uptake and translocation and its effects on the physiological metabolism of plants. Two experiments were carried out; I-Evaluation of uptake and translocation of C-diclosulam (35 g a.i.

Relation between changes in organic matter structure of poultry litter and heavy metals solubility during composting.

Poultry litter (PL) is widely used as fertilizer because of its rich N, P and Ca content. When PL is applied to previously untreated soil, it is a potential contaminant. Composting is an alternative for stabilizing organic and mineral components.