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.
Silicate agrominerals (SA) may be sustainable soil amendments that can minimize dependence on conventional fertilizers (CF). We evaluated the residual effects of SA application as a source of Si and as a soil remineralizer, using soils with contrasting chemical-physical features cultivated with soybean. The experiment was conducted under greenhouse conditions and treatments were arranged in a 5 × 2 + 2 factorial scheme: five rates of SA, two soils in addition to CF. The soil was incubated before cultivation, followed by the sequential sowing of corn and soybean. At the R4 phenological stage, when the pods were fully developed, soybean plants were harvested for anatomical leaf tissue analysis and P, Ca, Mg, and Si accumulation. After harvest, the soil was analyzed. Application of SA rates reduced potential acidity (H + Al) and exchangeable acidity (Al3+) and increased soil pH, sum of bases (SB), cation-exchange capacity (CEC), and base saturation (BS), in addition to promoting the nutrient’s availability and Si. Stomatal density was higher on the adaxial face of plants cultivated in the medium-textured soil. Silicate agrominerals can be used as a soil acidity corrector and remineralizer, improving the root environment and increasing the availability of nutrients and silicon.
The world’s population faces serious challenges related to food security, particularly in the agribusiness sector, as it grapples with dependence on mineral fertilizers in key producing regions, susceptible to tariff policy fluctuations and wars, amid climate change and population growth, despite increased food production enabled by new technologies and management practices. This narrative review synthesizes evidence on the main challenges to food security in Brazil, with emphasis on how agricultural production, land use, and mineral fertilizer dependence interact under global climate change. We employed comprehensive literature review methods and analyzed data from national and international agencies to compile relevant information on the influence of this scenario on agricultural production, providing an overview of the topic to understand trends and future projections of these challenges. The results revealed significant vulnerabilities in the sector, especially concerning reliance on imported mineral fertilizers to meet its full demand. In 2024, Brazil imported approximately 90% of the mineral fertilizers used in its agricultural sector, which heightens exposure to geopolitical and market shocks. Moreover, climate change also negatively impacts agriculture, raising production costs and prices of staple foods, thereby exacerbating food insecurity. Therefore, improving fertilizer use efficiency and adopting alternative fertilization sources, combined with conservation practices, represent key strategies to mitigate food insecurity. Among these strategies, reducing import dependence through improved fertilizer use efficiency emerges as the most immediately actionable priority, as it could reduce current demand by 20–30% within 5 years. This should be complemented by medium-term investments in alternative fertilizer sources and long-term climate adaptation measures. These actions can also support the promotion of sustainable development goals aligned with the United Nations’ 2030 Agenda. Aligning fertilizer strategies with climate-smart and low-carbon agriculture policies could simultaneously reduce greenhouse gas emissions and enhance the resilience of food systems.
27 November 2022 in Research, Society and Development
Em decorrência do uso da colheita mecanizada da cana-de-açúcar, se faz necessário estudos que preconizam o melhor rendimento operacional e econômico da colhedora. Logo, o objetivo do trabalho foi avaliar as perdas visíveis na colheita mecanizada de cana-de-açúcar em função de três rotações do extrator primário de uma colhedora automotriz (R1- 900 rpm, R2- 1.000 rpm e R3- 1.100 rpm) na velocidade operacional de (4 km h-1). Os dados foram analisados pelo controle estatístico de processo (CEP), onde foram utilizadas cartas de controle de valores individuais e de amplitude móvel para verificação das perdas. Foram utilizadas 60 parcelas amostrais de 13 m2, espaçadas 50 m entre si. As perdas foram separadas, pesadas, quantificadas, transformadas em kg ha-1 e classificadas de acordo com a metodologia proposta por Reis (2009). Os dados foram submetidos a análise estatística descritiva para verificação da normalidade e, posteriormente, confeccionado cartas de controle de valores individuais (CEP) para quantificação do volume de perdas e instabilidade do processo. Portanto, nas condições do trabalho causas especiais atuaram no processo de colheita tornando-o instável quanto às perdas. As maiores perdas totais foram observadas na rotação intermediária de 1000 rpm, seguido da maior rotação 1100 rpm.
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 (Ap1; 0–25 cm) and subsurface (Ap2; 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.