The root elongation rate represents a biophysical process that can be directly affected by mechanical, water, thermal, and gaseous stresses in the soil to be used as a soil physical quality indicator. The objective of this study was to determine sugarcane root growth parameters under soil physical stress for different root diameter classes in an Oxisol from the Southeast of Brazil. The experimental design was entirely randomized in a factorial scheme 5 × 2 (mechanical × water stress) with three replications. The factor mechanical stress was composed of five compaction levels (1.04; 1.12; 1.19; 1.28; 1.36 Mg m–3). The factor water stress was composed of two matric potentials (–6 kPa and –33 kPa). Soil samples were collected from the 0.0–0.2 m layer of an Oxisol with a clayey texture. Pre-sprouted sugarcane seedlings were transplanted and conditioned in a growth chamber. Root length, volume, surface area, and diameter were quantified to generate root growth models as a function of physical stresses in the soil. Soil penetration resistance increases from 1.4 to 5 MPa reduced root elongation rate from 3.5 to 1.35 cm day–1 (–59%) and the average number of roots from 11 to 6 segments (–45%), respectively. The root volume, surface area, and length were reduced because of the increase in the compaction level. Coarse root diameter (1–2 mm) was weakly impacted by mechanical stress, whereas fine root diameter (0.5–1 mm) was more growth limited in compacted soils. The root elongation rate of sugarcane was modelled as a function of mechanical and water stress. Mechanical stress mainly affects the growth of sugarcane roots with small diameter.

This work aimed to evaluate the impact of conversion from native vegetation to pastures and agriculture on soil quality in the Brazilian semi-arid region and identify which soil attributes have the greatest potential as soil quality indicators. We collected soil samples at 0–10 and 10–20 cm layers from seven municipalities in the Brazilian semi-arid region. We determined the stocks of total soil organic carbon (TOC), total nitrogen (TN), carbon and nitrogen from microbial biomass (MB-C, MB-N), oxidizable fractions, humic substances, granulometry, soil bulk density (BD), pH, P, and cation exchange capacity (CEC). The evaluated systems were pasture, agriculture with different implementation times, and native forest (Caatinga biome). The results show that conventional cultivation and grazing systems lead to substantial losses of fundamental attributes needed to maintain soil quality. The study observed losses of MB-C, TOC, TN, and more recalcitrant fractions like fulvic acid and humin, along with a reduction in soil P and CEC. Soil physical, chemical, and biological attributes work as indicators of separation between environments; however, labile compartments showed greater potential as indicators of land use changes, being considered the main indicators in the soil quality assessment.

The assessment of soil organic carbon (SOC) stocks relies on several key factors, including the total SOC content of the soil, the bulk density (BD) of the soil, and the depth of the sampled layers. However, traditional methods, particularly those using volumetric cylinders for undisturbed soil sampling, present significant logistical challenges for large-scale projects due to their costly and time-consuming nature, often requiring the excavation of trenches. In response, automated probes, which are commonly used in geological studies, offer a promising alternative, but their application in the context of BD soil studies remains under discussion. The objective of this study was to evaluate the efficacy of a tractor-mounted probe in comparison to the conventional core method for the collection of undisturbed soil samples across a range of soil textures and depths. The results indicated that the coefficient of variation (CV) for the probe’s bulk density (BD) measurements ranged from 3 to 15% in sandy soils but remained consistently below 5% in clay-sandy-loam and clay textures. Despite small differences in BD values between the methods used, SOC stock assessments showed only minor variations across all layers, regardless of soil texture. Therefore, this study demonstrated that the tractor-mounted probe represents a viable and scalable solution for conducting large-scale SOC stock assessments, despite its susceptibility to minor variations in sandy soil conditions. This research contributed to the field of automated soil sampling tool validation and offered alternatives for field operationalization in large-scale carbon projects. It also raised new questions for further investigation into other field conditions

Biological products used in soybean seed treatment can enhance soil microbial activity, thereby improving soil health. Brazil is the world‘s largest producer of soybeans and has a vast and diverse cultivation area characterized by varying weather and soil conditions. However, there is a lack of studies that have assessed the soil health response to soil biological conditioners based on calcium sulfate dihydrate applied by seed treatment at large-scale farmer-led and over extended periods in Brazilian soybean fields. To address this gap, we carried out a large-scale farmer-led study across a 3000-km transect to evaluate the soil health responses to a biological conditioner over three consecutive years. Soil health indicators including soil organic carbon, extracellular ß-glucosidase enzyme activity, soil bulk density, soil pH, available phosphorus, and exchangeable potassium were measured, interpreted, and integrated into a soil health index (SMAF-SHI) to compare experimental strips with and without of the soil biological conditioner. A dataset of 87 sampling points collected from 15 farmer-led experiments over three consecutive years of the soil biological conditioner application (i.e., 2021 corresponds to one application, 2022 to two applications, and 2023 to three applications) was analyzed. The results showed site- and year-specific alterations on soil chemical, physical, and biological indicators, as well as overall SMAF-SHI. In general, the effects of the soil biological conditioner application were subtle and statistically undetectable for most of the metrics over three consecutive years of application. However, we observed potential changes in soil organic carbon, extracellular β-glucosidase enzyme activity, and soil bulk density indicators after two and three years of the soil biological conditioner application. To further understand the long-term effects of biological conditioners on soil, we propose continued soil health monitoring over time, with a particular focus on the rhizosphere, and the inclusion of molecular biology methods to measure the abundance, diversity and functionality of the soil microbiome.

Soil health is a term used to describe the general state or soil quality in an agroecosystem. The study of aggregate formation pathways has been successfully used to assess soil quality, especially chemistry, particularly in measuring the impact of different forms of use and management on soil health. This study aimed to (i) verify the contribution of biogenic (Bio) and physicogenic (Phy) aggregates to soil fertility; (ii) evaluate the total carbon (TC), nitrogen (TN), phosphorus (TP), and potassium contents and their respective stoichiometric ratios in these aggregates; and (iii) analyse the relationship between the P fractions (labile, moderately labile, and non-labile) and these aggregates. Three management systems were evaluated (permanent pasture, PP; no-tillage system, NT; and no-tillage + Urochloa system, NT+B) as well as a reference area (Atlantic Forest biome vegetation, NF). All the sample areas are located on soils with a sandy texture in the surface horizons. Aggregates were separated, identified, and classified according to their genesis into Bio (biotic factors) and Phy (abiotic factors). Only the PP system had significant increase in the values of TC, TN, TP, TK, and organic and inorganic P. The NT+B system favoured a proportional increase in TC content compared to the aggregates of the NF and NT areas, especially in the subsurface layer (ranging from 31 to 44%). For Bio aggregates, there were increments in TC and TN contents compared to Phy ones, especially in the NT and NT+B systems (8 to 30% for TC and 56 to 239% for TN). Bio aggregates also had the lowest values of C/N ratio in the surface layer (< 30), highest values of C/P ratio in the subsurface layer (> 33), and greater participation of the organic form of P in TP in the surface layer (between 26 and 42%). The chemical attributes in the aggregates were affected differently by the soil management systems, especially PP and NT+B systems. The results verified for Bio aggregates strengthen the hypothesis that these structural units are important sources of nutrients for the soil and reiterate the importance of studying the formation pathways in assessment soil health.

Given the increasing global demand for sustainable agricultural practices, there is a growing need to evaluate the effectiveness of governance mechanisms. This paper presents a case study analysis of voluntary sustainability standards (VSS) and their impact on maintaining soil health in the context of soybean production, specifically in the Brazilian Savannah (Cerrado biome). The sustainability of soybean production certified by VSS ProTerra and Roundtable on Responsible Soy was evaluated on 35 farms, considering factors such as land use, deforestation, cultivation methods, pesticide usage, and their effects on soil health. The assessment of these factors was conducted through a comprehensive methodology that included field visits, soil sampling and laboratory analysis, remote sensing techniques using satellite imagery, and structured interviews with farm managers. VSS are private governance mechanisms that establish quality standards to be followed in various areas. The study shows that the standards are generally respected on certified farms and, in particular, excluding deforestation. The VSS promote incremental improvements within the overall context of large-scale, business-as-usual agriculture by promoting practices that enhance soil fertility, reduce erosion, and optimise input use. These actions can contribute to stronger soil health, boosting resilience, and productivity. The urgency of reconciling food production with climate change mitigation and adaptation will increase interest in and demand for sustainable agriculture certification in the coming decades. Therefore, the monitoring and verification of the effectiveness of those standards, as shown in our study, are fundamental to provide true benefits, transparency, and confidence to the market.

Intercropping annual cash crops with grasses is a strategy that promotes both diversification and intensification of production in the same area, contributing to sustainable food systems. This study evaluated the impact of intercropping maize with different Urochloa species on maize and subsequent soybean yields over three years in the Brazilian Savannah. The treatments included: (1) maize monoculture; (2) maize intercropped with Urochloa ruziziensis; (3) maize intercropped with U. brizantha cv. Marandu; and (4) maize intercropped with U. brizantha cv. BRS Paiaguás. The evaluations included maize grain yield, land equivalent ratio (LER), forage biomass and soybean yield in succession. The results confirmed that maize intercropped with U. brizantha cv. Marandu and U. brizantha cv. BRS Paiaguás achieved grain yields comparable to monoculture. Demonstrating that these forage species do not significantly compete with maize in 2018 and 2019 in Montividiu and 2018 and 2020 in Rio Verde. In Montividiu, intercropping with U. brizantha cv. BRS Paiaguás resulted in an average LER of 1.13 over three years, highlighting its advantage in optimising land use. In addition, the intercropping system was particularly beneficial in sandy soils, where faster biomass decomposition accelerated improvements in soil structure, moisture retention, and nutrient availability, leading to earlier benefits in soybeans grain yield compared to clay soils. These findings emphasise the potential of maize-forage intercropping to enhance land-use efficiency and soil health while maintaining crop yields in tropical agroecosystems. However, site-specific management is essential to maximise benefits and minimise trade-offs. Future research should focus on long-term soil health dynamics and refining intercropping strategies to improve sustainability in different environmental conditions.

Soil health refers to the ongoing ability of soil as a living ecosystem to maintain environmental quality, support crop productivity, and ensure human health. Evaluating and enhancing soil health is crucial for ensuring more productive and resilient agricultural systems. The aim of this work is to assess soil health using both on-farm and computational methods. The study was carried out on a slope with textural variation at Ponta Grossa–Paraná State, Brazil. The slope was divided into three segments based on altitude and clay content: upper, middle, and lower positions. In each segment, twenty points were sampled, resulting in a total of sixty points along the slope. Soil health was analysed at these points by visual evaluation of soil structure (VESS), and samples were also collected to use the Soil Management Assessment Framework (SMAF) approach in the 0–0.10 m and 0.10–0.20 m soil layers. The indicators used in this approach were soil organic carbon, macroaggregates, bulk density, water-filled pore space, pH, phosphorus, and potassium. The data were analysed using analysis of variance, mean comparison with Tukey’s test (p < 0.05). In addition, principal component analysis was performed on the soil health index (SHI) and its components (chemical, physical, and biological) with clay content and VESS scores. The study discovered that the upper position had the highest clay content, lower visual scores (2.44), and a higher SHI (up to 0.80) compared to the middle (3.7 and 0.78) and lower positions (2.9 and 0.73). This study highlights the significant influence of soil texture, particularly clay content, on soil structural quality and health as assessed by VESS and SMAF. Higher clay content improved soil aggregation and health, while lower clay content in the middle and lower slope positions resulted in poorer structure. VESS proved to be an effective field-based tool for rapid assessment of soil health, complementing the more detailed SMAF framework. The integration of both methods is essential for the development of adaptive and sustainable soil management strategies.

Globally, the use of biological products, including biological control agents, biofertilizers, and bioinoculants, has increased significantly as a strategy to reduce dependence on synthetic inputs and promote sustainable agriculture. However, its effects on soil health are still poorly explored. Therefore, this study aimed to analyse the multifunctionality of biological products in agriculture, focusing on soil health, using a systematic review and bibliometric analysis approach. This analysis involves summarizing their mechanisms of action, categories, and impacts. Parameters such as the number of publications per year, the most cited articles, the frequency of keywords and international scientific collaboration networks between countries were analysed. The results showed an expansion in the number of publications on biological products and biological products over the years, with a significant growth in recent years, with emphasis on Brazil and Russia. The most frequent keywords include ‘biological products’, ‘biological product’, ‘soil’, ‘fungi’, ‘bacteria’, and ‘biological control’, and the most cited articles address topics such as the use of Azospirillum sp. in agriculture, the combined application of biological products to control soil diseases, and the inoculation of seeds with Bacillus subtilis. Although few studies have directly evaluated soil health, the results indicate that biological products are related to improvements in soil health, which stimulate the microbiota and promote greater productivity, thereby positively impacting the physical and chemical properties, highlighting the importance of an integrated approach for soil health.

Climate change (CC) challenges food and climate through reduced crop yields and increasing production risk. Regenerative agriculture (RA) emerged as a pivotal strategy for enhancing crop productivity and soil organic carbon (SOC) sequestration, contributing to agriculture’s CC mitigation and resilience. Nevertheless, expanding RA’s main challenges is providing sufficient science-based decision support for farmers and other stakeholders. In this context, we present herein the largest public-private partnership in Brazil to conduct research in a multidisciplinary collaborative scientific network on RA and describe the Carbon Farming Program approaches. Bayer SA leads the initiative, which also includes 11 partner institutions (i.e., Universities, Research Institutions and Foundations, and Farmers organisations). The programme aims to assess the benefits of improvement of cropland management, intensified and biodiverse crop rotation plans on SOC, soil health, crop productivity, and profitability in a no-till system. The programme has a multi-scale approach with three main steps (‘Research Partners’, ‘On-Farm Research Sites’, and ‘Carbon Program at Scale’). In total, it encompasses 1,906 farmers and 232 000 hectares across the Brazilian edaphoclimatic conditions. The programme has gathered a large database, integrating SOC and fertility determinations, and crop yields, to derive a quantitative evaluation of the impacts of sustainable agricultural land management practices adoption. Moreover, the programme enabled breaking through the gap of quantitative knowledge for the development of a novel mathematical model to predict SOC dynamics for tropical agroecosystems. This is worth supporting assertive decisions along the specific planning to promote scalability in the insertion of Brazilian agriculture in the global C market.

Bibliometric research illuminates the scientific development of soil health (SH) studies in the Brazilian Semiarid, which are crucial for sustainable agriculture and mitigating climate change impacts. However, research trends on SH in the Brazilian Semiarid are still not well understood. This study aimed to illustrate how SH has been addressed in research concerning the Brazilian Semiarid. Terms such as ‘soil health,’ ‘soil quality,’ ‘biological quality,’ ‘chemical quality,’ ‘physical quality,’ as well as ‘Caatinga,’ ‘Brazilian Semiarid,’ and ‘Brazilian Northeast’ were searched in the Scopus® database. Bibliometric parameters were catalogued by the number of publications per year, most cited articles, primary institutions, main journals, and keyword frequency. The articles were evaluated based on the examination of chemical, physical, and biological indicators, and a similarity test was conducted to group articles according to these indicators. The bibliometric analysis reveals a significant increase in scientific output since 2020. Embrapa research centres contribute significantly to this expanding body of knowledge, with the leading journal ‘Revista Caatinga’ reflecting a specialized focus on the region’s unique challenges. The most evaluated indicators were pH, soil organic carbon, P, Ca2+, Mg2+, K+, and bulk density, but the prevalence of biological indicators, such as soil organic carbon (SOC), activity of enzymes such as alkaline and acid phosphatase, and ß-glucosidase, microbial activity, and soil fauna, underscores key research themes. These findings highlight the practical implications of SH research, but while increased research is commendable and increasingly necessary, studies are still scarce. Increased research is vital for the development of strategies that contribute to the long-term sustainability of the Brazilian Semiarid region.