Micropedologia de um Argissolo amarelo com horizontes antrópicos (Terra Preta de Índio) na Amazônia Central.

Estudos micropedológicos foram carreados em Terra Preta de Índio (TPI) com o objetivo de elucidar os processos envolvidos em sua gênese, bem como suas formas de utilização pré-colombiana. Blocos indeformados de solo foram coletados por horizonte e em suas respectivas transições em um perfil de Argissolo Amarelo A Antrópico (TPI) localizado no município de Iranduba, AM. As lâminas delgadas confeccionadas a partir dos blocos foram descritas por meio de microscopia óptica. Os resultados mostraram que os processos envolvidos na gênese desse solo envolveram: i) condições pedoambientais diferentes das atuais (pedorrelíquias - nódulos ferruginosos); ii) argiluviação, indicada por revestimentos de ferri-argilãs orientados na parede de poros entre agregados e canais; iii) migração de ferro impregnando o fundo matricial (cutãs de difusão); iv) bioturbação, atestada por preenchimento de poros por pelotas fecais e microagregação zoogenética e v) antropismo, que contribuiu com a queima de resíduos (partículas de carvões) e descarte de artefatos cerâmicos. A análise dos fragmentos cerâmicos corroborou a utilização de cauixi (Tubella reticulata e Parnula betesil) e cariapé (Bignoniacea) como antiplástico para o seu fabrico

Caracterização de sintomas de deficiências em mudas de teca (Tectona grandis L. f.).

Este estudo teve por objetivo caracterizar os sintomas visuais de deficiência de macro e micronutrientes em mudas de teca.bitstream/item/24801/1/ct90-teca.pd

Work issues on Tomatec: tomato sustainable production system.

Tomatec is a tomato sustainable production system. It encompasses a set of good practices on the crop. The main practices are: irrigation through waterdropping, fertilization within irrigation (ferti-irrigation), integrated pest control (which heavily reduces the use of pesticides), good soil handling with no-tillage cropping and use of contours for planting, use of tiny wires for supporting tomato trees (instead of bamboo logs) and the enveloping of the fruits with paper bags. Enveloping remains as one of the most important practices due to two factors: first, it is visible. Tomatec crops are easily recognized by people because of the white paper bags that involves all bunches, turning all plantation into white. The other reason is because enveloping is a very laborious process, and the key for having fruits free of pesticide residues. In order to assess the impacts of Tomatec, using the Ambitec method, we have conducted four interviews with Tomatec producers in the State of Rio de Janeiro, Brazil. These interviews happened on 2019 September and took place in four municipalities: Tanguá, Nova Friburgo, Teresópolis and São Sebastião do Alto. Producers mention that farmworkers use individual protection equipment during their works. On field, we have seen hats and jackets. They mentioned that farmworkers also use masks for pesticides aspersion. Concerning to labour time, we have observed two main ways of contracting. Smaller producers usually work themselves in the fields. On harvest time, they contract many farmworkers, which are payed by numbers of day working. Bigger ones contract farmworkers by month and sign their workcard, paying the wages as well as the labour benefits, as disposed by Brazilian law. Another interesting finding about work on Tomatec is the genre division. All producers mentioned that pesticide sprinkle is exclusive to men, and enveloping is exclusive to women. It is not defined by rural producers: the farmworkers actually ask for that. Producers reported that farmworkers realize that sprinkling is a more painful and dangerous activity, with potential harms to fertility. Although Tomatec is recognised by strongly reducing the total amount of chemical products on the crop, men still want to save women from that kind of activity. On the other hand, enveloping is considered by farmworkers and producers a more delicate activity. It demands agility and precision to put on the paper bags on tomato flowers and to clip them, making the tomato fruits growing up inside the bags without receiving any drop of pesticide. Men are considered slower and less efficient than women to carry on this activity. So, analysing work issues on Tomatec we can see that the adoption of this production system have established many different strategies to deal with safety, law and genre issues

Uso de fungicidas e óleo de Piper aducun (dilapiol) para o controle de Colletotrichum musae.

A banana está entre as frutas mais produzidas e consumidas no Brasil. A antracnose (Colletotrichum musae) é a principal doença pós-colheita em frutos, porém, a infecção inicia no campo. O controle da antracnose é difícil, e o estudo de produtos químicos e alternativos que reduzam as infecções e seu progresso nos frutos é importante no manejo da doença

Cycling of N and P in Grass-Alone (\u3ci\u3eBrachiaria\u3c/i\u3e) and Mixed Grass/Legume (\u3ci\u3eBrachiaria/ Desmodium ovalifolium\u3c/i\u3e) Grazed Pastures in the Atlantic Forest Region of Brazil

There are estimated to be \u3e 80 M ha of Brachiaria pastures in the tropical regions of Brazil. When continuously grazed with only modest fertiliser inputs (and no N) these pastures can maintain reasonable cattle weight gains (\u3e 200 kg LWG/ha per year). However, without fertiliser and when overgrazed, LWGs fall rapidly to low levels. Recent studies have shown that N and P deficiency are the most important factors limiting productivity. The objective of this study was to study fluxes of N and P in the pasture system in order to understand resilience to poor management and minimum nutrient requirements to guarantee their sustainability

Carbon content in sandy soils under different use and management systems.

Quantifying soil carbon content is important to assess soil indicators related to adequate management conducted by producers in their agricultural systems. The objective of this study was to evaluate the total soil carbon content in soils under different use and management systems

Carbon content in sandy soils under different use and management systems.

Quantifying soil carbon content is important to assess soil indicators related to adequate management conducted by producers in their agricultural systems. The objective of this study was to evaluate the total soil carbon content in soils under different use and management systems