Investigação da poluição por metais tóxicos no córrego do Cintra

Cintra stream is the major receiver of treated effluent from sanitary, hospital and research laboratory sewage from the UNESP campus in Botucatu, Rubião Júnior District, São Paulo state; and it has shown evidence of diffuse contamination by metals along it. Analyses of the most toxic metals (Pb, Cu, Fe, Ni and Zn) were carried out by using an atomic absorption spectrometer AA-6.800 - Perkin Elmer, analyst 700. ANOVA followed by the Tukey test were used for data analyses at 5% significance level. The main objective of this study was to compare current data on metal levels with data from other studies, in the same area, and of the same nature, conducted before and after implementation of chemical residue management by the university in 2008. Also, it aimed at identifying and quantifying possible diffuse and punctual contamination. Sites S1 and S2 showed punctual contamination, while diffuse sources were observed between S4 and S5. The quality of water in the Cintra Stream improved after establishment of the program of laboratory chemical residue management in the Campus of UNESP.

Potencial de contribuição e importância socioambiental dos 'catadores autônomos' de Rio Claro (SP) para o programa de coleta seletiva municipal

The Urban Solid Residues are the rests of human activity, popularly known by trash and considered by population like useless, undesirable and disposable. On the other hand, for the waste pickers, solid residues are the beginning of a cycle: they see in the other's people trash the only income, an economic value. Currently, in brazilian cities, one million collectors act, alone or in cooperatives, socially excluded by the work they do. The National Policy of Solid Residues (PNRS), instituted in 2010, established guidelines to the execution of integrated residues management, with should be practiced by city halls and other governmental institutions. This policy has, besides other things, goals of residues reduction and inclusion of waste pickers in the mechanism of selective collect and recycling. However, this and other public policies created for residue management are benefic only for cooperated waste pickers. That could negatively affect most of this class, since 90% are waste pickers working in a precarious way on the country's streets. This study has for objective show that most of waste pickers that work in a precarious way on the brazilian territory has a huge potential for the solid residues recycling chain and how they should be valued for the environmental services they provide, so they can be included with dignity on the society, ensuring economic and social benefits for this workers. The methodology adopted was based on the amount of residue collected by the 44 cooperated members of the Rio Claro‟s waste pickers cooperative to estimate the potential of collect and recycling did by 210 autonomous waste pickers who are active on city streets. It was observed that the cooperative collects the equivalent of 10.2% of all recyclable residues generated by city population. However, with the potential that these autonomous waste pickers have, which together could contribute 465 tonnes of solid residues per month, or 5,570 tons a year...

Availability of soil water under tillage systems, mulch management and citrus rootstocks

The increased availability of soil water is important for the management of non-irrigated orange orchards. The objective of this study was to evaluate the availability of soil water in a Haplorthox (Rhodic Ferralsol) under different tillage systems used for orchard plantation, mulch management and rootstocks in a "Pera" orange orchard in northwest Parana, Brazil. An experiment in a split-split-plot design was established in 2002, in an area cultivated with Brachiaria brizantha grass in which three tillage systems (no tillage, conventional tillage and strip-tillage) were used for orchard plantation. This grass was mowed twice a year between the rows, representing two mulch managements in the split plots (no mulching and mulching in the plant rows). The split-split-plots were represented by two rootstocks ("Rangpur" lime and "Cleopatra" mandarin). The soil water content in the plant rows was evaluated in the 0-20 cm layer in 2007 and at 0-20 and 20-40 cm in 2008-2009. The effect of soil tillage systems prior to implantation of orange orchards on soil water availability was less pronounced than mulching and the rootstocks. The soil water availability was lower when "Pera" orange trees were grafted on "Cleopatra" mandarin than on "Rangpur" lime rootstocks. Mulching had a positive influence on soil water availability in the sandy surface layer (020 cm) and sandy clay loam subsurface (20-40 cm) of the soil in the spring. The production of B. brizantha between the rows and residue disposal in the plant rows as mulch increased water availability to the "Pera" orange trees.

Determination of the optimal quantity of crop residues for energy in sugarcane crop management using linear programming in variety selection and planting strategy

The aim of this work was to present organizational models for optimizing the reduction of crop residue generated by the sugarcane culture. The first model consisted of the selection of varieties of sugarcane to be planted meeting the mill requirements and, at the same time, to minimize the quantity of residue produced. The second model discussed the use of residue to produce energy. This is related to the selection of variety and quantity to be planted, in order to meet the requirements of the mill, to reduce the quantity of residue, and to maximize as much as possible the energy production. The use of linear programming was proposed. The two models presented similar results in this study, and both may be used to define the varieties and areas to be cultivated. (C) 2001 Published by Elsevier B.V. Ltd.

Alternative uses for vinasse, an alcohol industry residue. A review

Recent studies on the recycling of vinasse, its potential use in agriculture and possible environmental problems resulting from the use and disposal of this residue are reviewed.

Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC) and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp.) residues to the short-term CO2-C loss, we studied the infl uence of several tillage systems: heavy offset disk harrow (HO), chisel plow (CP), rotary tiller (RT), and sugarcane mill tiller (SM) in 2008, and CP, RT, SM, moldboard (MP), and subsoiler (SUB) in 2009, with and without sugarcane residues relative to no-till (NT) in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47% and 41%, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

The management of cover plant residues for cotton cropped in a no-tillage system

The cutting of plant residue in no-tillage systems under certain environmental conditions becomes necessary to adequately establish and grow crops. This study aims to assess the effect on the yield of different methods of managing millet plant residue in cotton plantations. The study was conducted during the agricultural years 2006/07 and 2007/08, and the treatments included no-mechanical-treatment tillage and the use of a rotary shredder, crimper-roller, and mechanical disintegrator for millet plants before sowing the cotton. Evaluations were performed for the residue fragmentation, emergence speed, percent of soil cover during the cycle and yield of the cotton crop. The emergence speed was faster in the management with the rotary shredder. In 2006/07, the no-tillage treatment showed a rate of loss for soil cover that was 46 percent greater than the disintegrator treatment. The rotary shredder and the disintegrator yielded greater soil coverage during the cultivation cycle, and the yield was highly correlated with the soil cover at 75 days after emergence. The management of the millet residue affected the cotton plants for the two-year study period.

Management Impacts on Soil Organic Matter of Tropical Soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)