Sugarcane demands large amounts of nutrients to reach a high level of productivity. Nutrients are generally supplied by mineral fertilizers, but their high costs and negative environmental impacts have generated interest in greater use of organic nutrient sources such as composted sewage sludge (CSS). In this study, we evaluated changes in soil chemical properties after the application of CSS or CSS/mineral fertilizer (MF) combinations to soil containing sugarcane seedlings under nursery conditions. Treatments included: T1: conventional mineral fertilization (MF) without application of CSS, T2: 100% of the recommended MF (06–30–24); T3: application of 2.5 Mg⁻¹ CSS; T4: 5.0 Mg⁻¹ CSS, T5: 7.5 Mg⁻¹ CSS, T6: 2.5 Mg⁻¹ CSS and 50% MF, T7: 5.0 Mg⁻¹ CSS and 50% MF, T8: 7.5 Mg⁻¹ CSS and 50% MF, T9: 2.5 Mg⁻¹ CSS and 100% MF, T10: 5.0 Mg⁻¹ CSS and 100% MF, T11: 7.5 Mg⁻¹ CSS and 100% MF. Soil chemical properties were evaluated from the soil surface (0.0–0.25 m) and subsurface (0.25–0.50 m) horizons. The results showed that the increase in CSS application did not affect soil organic matter content at either depth, while Zn concentrations increased in the soil subsurface horizon. The application of CSS at 5.0 Mg ha⁻¹ with or without 50% MF resulted in the highest pH values, sum of bases, cation-exchange capacity, P, K, Ca, Mg, Cu, and Zn in surface horizons. The use of CSS as an organic fertilizer in sugarcane nurseries improves soil fertility, reduces mineral fertilizer requirements, and, thus, facilitates the sustainable disposal of sewage sludge.

Composted sewage sludge (CSS) is an organic fertilizer that can be used as a source of micronutrients in agriculture. However, there are few studies with CSS to supply micronutrients for the bean crop. We aimed to evaluate micronutrient concentrations in the soil and their effects on nutrition, extraction, export, and grain yield in response to CSS residual application. The experiment was carried out in the field at Selvíria-MS, Brazil. The common bean cv. BRS Estilo was cultivated in two agricultural years (2017/18 and 2018/19). The experiment was designed in randomized blocks with four replications. Six different treatments were compared: (i) four increasing CSS rates, i.e., CSS5.0 (5.0 t ha⁻¹ of applied CSS, wet basis), CSS7.5, CSS10.0, CSS12.5; (ii) a conventional mineral fertilizer (CF); (iii) a control (CT) without CSS and CF application. The available levels of B, Cu, Fe, Mn, and Zn were evaluated in soil samples collected in the 0–0.2 and 0.2–0.4 m soil surface horizons. The concentration, extraction, and export of micronutrients in the leaf and productivity of common beans were evaluated. The concentration of Cu, Fe, and Mn ranged from medium to high in soil. The available levels of B and Zn in the soil increased with the residual rates of CSS, which were statistically not different from the treatments with CF. The nutritional status of the common bean remained adequate. The common bean showed a higher requirement for micronutrients in the second year. The leaf concentration of B and Zn increased in the CSS7.5 and CSS10.0 treatments. There was a greater extraction of micronutrients in the second year. Productivity was not influenced by the treatments; however, it was higher than the Brazilian national average. Micronutrients exported to grains varied between growing years but were not influenced by treatments. We conclude that CSS can be used as an alternative source of micronutrients for common beans grown in winter.

Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be used as an organic fertilizer to improve growth, yield, and quality of sugarcane. However, there is a lack of information regarding the impact of CSS application on sugarcane seedling performance in nursery environments. A field study was conducted using a randomized complete block design to evaluate the development, nutritional status, productivity, and technological quality of sugarcane seedlings after CSS application with or without mineral fertilizer. Morphological variables (stem height, diameter, and number, as well as leaf area), technological attributes (total recoverable sugar: ATR; quantity of sucrose in sugarcane juice: Pol; Brix: percentage (weight/weight) of soluble solids contained in juice; TAH: tons of sugar per hectare), nutritional status, and sugarcane productivity were evaluated. Treatments did not influence morphological and technological variables except for TAH but did positively alter nutritional status and seedling productivity. The application rates of 5.0 and 7.5 Mg ha⁻¹ of CSS with or without mineral fertilizers (MF) provided the greatest increase in crop productivity. Our results indicate that CSS can be a sustainable nutritional management option in sugarcane seedling nurseries, resulting in greater crop productivity at lower mineral fertilization rates.

As mudanças no uso e cobertura da terra são tidas como causadoras de grande degradação ambiental à medida que a floresta é convertida em outros usos. No Estado do Pará a principal atividade responsável pelo desmatamento é a pecuária, logo deve-se realizar estudos visando a identificação das mudanças no uso da terra devido a proteção do meio ambiente. Por esse motivo, o objetivo desse estudo foi analisar o desmatamento no município de São Felix do Xingu/Pará. Para o desenvolvimento do estudo foram utilizados dados fornecidos do Instituto Nacional de Pesquisas Espaciais – INPE que disponibiliza dados diários, mensais e anuais sobre os índices de desmatamento e degradação nas regiões brasileiras e quais atividades são exploradas. A partir disso, identificou-se que nos últimos anos a taxa de desmatamento só cresce de forma variável e rápida ao longo da temporalidade, sendo 54.167,5 km² de área devastada entre os anos de 2010 a 2019. Apenas em 2010 o território xinguense obteve 20,18% de destruição causada nas áreas florestais. Percebe-se que em 2015, os números saltaram para 21,23% comparado a 2010 e, assim os valores continuam maximizando em 2019 girando em torno de 22,88%. Com a análise temporal foi possível observar novas frentes de desmatamento que estão se dirigindo para Nordeste, Noroeste (paralelas ao rio Xingu) e Oeste (adentrando-se para a Terra do Meio). Logo, deve-se ter uma maior fiscalização por parte dos órgãos públicos nessas áreas, uma vez que a exploração ilegal e a pressão pelos recursos naturais estão aumentando com o passar dos anos.

Conventional mineral fertilization (CMF) is a common practice in infertile sugarcane-cultivated tropical soils, increasing production costs and environmental concerns. Combining CMF with composted sewage sludge (CSS) could be a sustainable strategy. We aim to evaluate changes in soil chemical properties, macro- and micronutrient concentrations in the soil surface (A_p1; 0–25 cm) and subsurface (A_p2; 25–50 cm) horizons, after CSS application with or without CMF in sugarcane cultivation (first and second ratoon cane). Eleven treatments, featured by CSS increase rates and mixed with CMF at different concentrations, were tested in the first ratoon; during the second, the CSS residual effect was evaluated. Applying CSS in sugarcane-cultivated soils, improved the following: (i) soil organic matter, pH, the sum of bases, cation-exchange capacity, and base saturation; (ii) overall nutrient concentrations (P, K, Ca, Mg, B, Cu, and Zn). The treatments showing the best performances were those with 5.0 Mg ha⁻¹ of CSS. Composted sewage sludge has the potential for use as an organic natural fertilizer reducing the need for CMF. When applied in infertile tropical soils, additional positive effects can be achieved, such as decreasing production costs and providing socio-economic benefits.

As geotecnologias estão cada vez mais acessíveis e isto se deve aos softwares livres e gratuitos estarem sendo progressivamente produzidos e difundidos, bem como também a adequação da linguagem destes softwares que vem sendo demandada, de forma a possibilitar o acesso a um público cada vez mais amplo. O objetivo é diagnosticar a utilização das geotecnologias, como instrumento de ensino da Geografia. O referido estudo foi realizado em loco com alunos de 6º ano na escola pública de âmbito Estadual Prof.º Virgílio Libonati localizada na região metropolitana de Belém do Pará, cujo o par de coordenadas para acesso é 01°27'9.73" latitude Sul e 48°26'38.22" longitude Oeste. A metodologia incluiu a aplicação de questionários após uma palestra com a finalidade de melhor entendimento sobre a cartografia, o meio ambiente e utilidades computacionais. O público algo foram 20 (Vinte) alunos na faixa etária de 11 anos pertencente ao turno vespertino. Essa abordagem destacou a importância das geotecnologias no cotidiano escolar procurando tornar mais dinâmico e eficaz os conceitos geográficos durantes o processo de ensino-aprendizagem.