Biochar is a solid material formed during biomass thermochemical decomposition processes. This organic compound has particular properties that may cause effects on soils depending on its feedstock and processing conditions. Thus, the characteristics and purpose of use of this material must be recognized prior to its use. Two types of biochar, derived from different wood sources, were compared, one from caatinga biome species and another from cashew trees. Two species from caatinga biome were used, jurema-preta (Mimosa tenuiflora Willd. Poir.), and marmeleiro (Croton sonderianus Müll. Arg.). This study aimed to identify the best biochar material regionally available to increase water-holding capacity in the soil, based on laboratory tests and microstructural porosity evaluation. Biochar from Caatinga wood demonstrated an improved water-holding capacity if compared to cashew wood biochar. The particle diameters of 2 and 4 mm showed the highest levels, which were 2,268 g.g^-1 for caatinga wood and 0.574 g.g^-1 for cashew wood biochars, respectively. While the smaller quantities of macropores and a larger number of micropores (smaller radius) could explain the higher water-holding capacity for biochar from caatinga wood, the thick lignified cell walls of biochar from cashew wood support the idea of a hydrophobic effect contributing to water lower holding capacity.

Several agro-industrial, livestock, and food wastes can be recycled to create biofertilizers. This diversity of raw materials can result in nutritional imbalance and an increase in heavy metal content, which could make the final product unfeasible. Thus, the chemical characterization of the raw materials and their influence on the sustainable and safe production of biofertilizers need to be better understood. In this context, the objective of the present study was to evaluate the chemical characteristics of agro-industrial residues used in the manufacture of an aerobic liquid biofertilizer. We analyzed the macronutrient, micronutrient, and trace metal contents of seven waste products used as raw materials to create a biofertilizer. In addition, a survey of secondary biofertilizer data from different residues was carried out that showed great heterogeneity in the chemical compositions of these residues, which has a direct impact on the agronomic efficiency of these biofertilizers. The characterization revealed that some materials may be contaminants of the soil, due to high levels of trace metals, especially cadmium. We conclude that the generation of detailed inventories, such as those of the nutrient and heavy metal contents of the raw materials and biofertilizers produced, is indispensable for the correct recommendation of biologically-based inputs in agriculture.

The present work aimed to evaluate the behavior of ten fertility attributes of soil organic matter physical fractions and total organic carbon upon addition of three EM Bokashis to a Rhodic Ferralsol (FRr) and a Dystric Cambisol (CMd). An experiment was carried out in greenhouse in which the soils were placed into plastic trays and cultivated with tomato. A completely randomized design was used with four repetitions and factorial scheme of 2 × 3 + 2, consisting of two soils (FRr and CMd), three EM Bokashis (Poultry Manure Bokashi (BPM); CNPH Bokashi (BC); and Cattle Manure Bokashi (BCM)), and two controls (both soils without addition of Bokashi). The following fertility attributes were evaluated: pH, Ca²⁺, Mg²⁺, K⁺, Na⁺, P, SB, H + Al, CEC, andV. Particulate organic carbon (POC) and mineral-associated organic carbon (MOC) and total organic carbon (TOC) were also investigated. Finally, the Principal Component Analysis was conducted in order to identify possible patterns related to soils when fertilized with EM Bokashi. The addition of EM Bokashi increased the soil fertility and contents of POC. Different EM Bokashi presents distinguished effects on each soil. The PCA suggests that BPM presents higher capacity to modify the analyzed chemical attributes.

The intensive nature of soil use in vegetable production areas has led to a marked decrease in soil quality. The objective of this study was to evaluate the effects of adoption of soil management systems on vegetable production with regards to the chemical properties of a Rhodic Ferralsol after five years and to evaluate the use of the Principal Component Analysis (PCA) statistical tool in discriminating the different treatments. The experiment was conducted under field conditions in central Brazil in a randomized block design with four replications and a 3 × 2 factorial arrangement (three soil management systems × two cover crops). The soil management systems used were NT (no-tillage), RT (reduced tillage), and CT (conventional tillage). The cover crops used were corn (Zea mays) alone and corn intercropped with the gray velvet bean (Stizolobium niveum). Reduced tillage showed the highest values of sum of bases, cation exchange capacity (T), and total organic carbon contents in the 0.00-0.05 m layer. In the same layer, RT and CT showed higher values of pH and K content. No-tillage and RT showed the highest P and Ca²⁺ contents and H+Al and T values. In the 0.05-0.10 m layer, RT had higher a pH value and Mg²⁺ contents. No-tillage and CT had higher potential acidity in this layer. The management systems (0.10-0.30 m) and the cover plants (all layers) had no effect on the properties analyzed. The use of PCA determined that the two principal components explained the following percentage of the data variance: 90.8 % (0.0-0.05 m), 79.8 % (0.05-0.10 m), and 83.1 % (0.10-0.30 m). Analysis of the eigenvectors and the grouping of treatments in PCA also showed that RT was most effective in improving soil fertility properties. Reduced tillage was most effective in increasing soil fertility after five years. The PCA is recommended as a useful tool and it allowed the identification of patterns not revealed by traditional tools.

Lettuce (Lactuca sativa L.) is one of the most produced and consumed vegetables in Brazil. As a crop of Mediterranean origin and therefore adapted to cool and/or mild climates, it is strongly affected by high temperatures. Morphophysiological disorders such as premature bolting and tipburn are examples of these impacts. Such problems are expected to worsen under projected scenarios of global warming and climate change. Therefore, this study aimed to assess the vulnerability of Brazilian lettuce production to two global climate change scenarios (RCP 4.5 and RCP 8.5) throughout the 21st century, using the regional climate model ETA-HadGEM2-ES, as well as the impacts of what we defined here as the Thermal Severity Index, calculated by summing the vulnerability indices of mean temperature and maximum temperature. Projections of mean temperature (Tmean) and maximum temperature (Tmax) were analyzed for the four seasons of the year, generating thematic maps of climate vulnerability and the Thermal Severity Index (IS), which integrates both variables. The results indicate a generalized warming trend, more pronounced under the RCP 8.5 scenario, with significant impacts on lettuce production, especially in the Central-West, Northeast, and Northern regions. Impacts will be greatest during summer and spring. By the end of the century, in both scenarios, almost the entire country, across all seasons, will present high to very high IS values. Only the Southern region and parts of mountainous areas showed high suitability for lettuce cultivation. The urgent adoption of climate change adaptation strategies and improvements in production system resilience is therefore necessary. As lettuce cultivation is highly associated with family farming—largely neglected in current climate change actions, this also becomes a matter of climate justice.

The Brazilian Cerrado is one of the global biodiversity hotspots. Despite its environmental importance, worrying rates of environmental degradation have been observed there. Therefore, the conservation of native areas or those undergoing recovery is important, and those under public administration have a greater chance of achieving this. The preservation of Brazilian biomes, maintaining their resilience and environmental services, is not only a matter of this but also of maintaining diffuse rights, especially those related to the maintenance of functional ecosystems for current and future generations. To this end, an adequate characterization of their environmental compartments is necessary. Given all the above, this study aimed to characterize pedogeomorphologically an area under Cerrado regeneration in the Federal District (DF), under the ownership of Embrapa (2025) Hortaliças since 1972. This area fulfills an important function by guaranteeing environmental services such as water production, as well as maintaining its quality and mitigating negative impacts. Geographic Information Systems (GIS), remote sensing from high-resolution images (0.5 m x 0.5 m), Digital Elevation Models (DEM) (SRTM) with a resolution of 30 m, contour lines plotted with an equidistance of 5 m, field visits, and chemical, physical, and physicochemical analyses of soil samples collected in the area were used. The results generated a semi-detailed soil reconnaissance map at a scale of 1:10,000, a DEM, a map of slope classes and land use and occupation of the study area. The results also indicated the predominance of Red-Yellow Latosols in the Intermediate Plateaus, Haplic Cambisols in steeper areas (Chapada edges), and Red Latosols in the highest part of the landscape (Chapada). The elevation profile shows that the area exhibits geomorphological compartmentalization, typical of the Central Plateau, with flat to gently undulating plateaus at altitudes around 1,000 m, steeply inclined dissected valleys (Chapada Borders), and the Intermediate Plateau at altitudes around 900 m, also featuring flat to gently undulating relief. The area also hosts several springs, exhibiting dendritic drainage with embedded valleys and bodies of water. Land use and occupation mapping at a scale of 1:1,000 confirms the area's degree of conservation. It is concluded that the area is predominantly composed of soils with high infiltration capacity in the plateaus and intermediate plateaus and presents a high risk of soil loss due to erosion in steep areas, which can lead to water quality loss through siltation.