Intensive cropland expansion for an increasing population has driven soil degradation worldwide. Modeling how agroecosystems respond to variations in soil attributes, relief and crop management dynamics can guide soil conservation. This research presents a new approach to evaluate soil loss by water erosion in cropland using the RUSLE model and Synthetic Soil Image (spectroscopy technique), which uses time series remotely sensed environmental, agricultural and anthropic variables, in the southeast region of São Paulo State, Brazil. The availability of the open-access satellite images of Tropical Rainfall Measuring Mission (TRMM) and Landsat satellite images provided ten years of rainfall data and 35 years of exposed soil surface. The bare soil surface and agricultural land use were extracted, and the multi-temporal rainfall erosivity was assessed. We predict soil maps’ attributes (texture and organic matter) through innovative soil spectroscopy techniques to assess the soil erodibility and soil loss tolerance. The erosivity, erodibility, and topography obtained by the Earth observations were adopted to estimate soil erosion in four scenarios of sugarcane (Saccharum spp.) residue coverage (0%, 50%, 75%, and 100%) in five years of the sugarcane cycle: the first year of sugarcane harvest and four subsequent harvesting years from 2013 to 2017. Soil loss tolerance means 4.3 Mg ha⁻¹ exceeds the minimum rate in 40% of the region, resulting in a total soil loss of ~6 million Mg yr⁻¹ under total coverage management (7 Mg ha⁻¹). Our findings suggest that sugarcane straw production has not been sufficient to protect the soil loss against water erosion. Thus, straw removal is unfeasible unless alternative conservation practices are adopted, such as minimum soil tillage, contour lines, terracing and other techniques that favor increases in organic matter content and soil flocculating cations. This research also identifies a spatiotemporal erosion-prone area that requests an immediately sustainable land development guide to restore and rehabilitate the vulnerable ecosystem service. The high-resolution spatially distribution method provided can identify soil degradation-prone areas and the cropland expansion frequency. This information may guide farms and the policymakers for a better request of conservation practices according to site-specific management variation.

Process-based models (PBM) are important tools for understanding the benefits of Integrated Crop-Livestock Systems (ICLS), such as increasing land productivity and improving environmental conditions. PBM can provide insights into the contribution of agricultural production to climate change and help identify potential greenhouse gas (GHG) mitigation and carbon sequestration options. Rehabilitation of degraded lands is a key strategy for achieving food security goals and can reduce the need for new agricultural land. This study focused on the calibration and validation of the DayCent PBM for a typical ICLS adopted in Brazil from 2018 to 2020. We also present the DayCent parametrization for two forage species (ruzigrass and millet) grown simultaneously, bringing some innovation in the modeling challenges. We used aboveground biomass to calibrate the model, randomly selecting data from 70% of the paddocks in the study area. The calibration obtained a coefficient of determination (R²) of 0.69 and a relative RMSE of 37.0%. During the validation, we used other variables (CO₂ flux, grain biomass, and soil water content) measured in the ICLS and performed a double validation for plant growth to evaluate the robustness of the model in terms of generalization. R² validations ranged from 0.61 to 0.73, and relative RMSE from 11.3 to 48.3%. Despite the complexity and diversity of ICLS results show that DayCent can be used to model ICLS, which is an important step for future regional analyses and large-scale evaluations of the impacts of ICLS.

The application of rock dust (RD) in agricultural soils has shown the capacity to improve soil conditions for plant growth. However, the successful use of RD requires understanding its effects on weathering in soil surfaces and its possible products. In this study, we present the results of an exploratory test in which a RD had its weathering intensified in a soil column by temperature (45 °C) and intense leaching (1,339.2 mm in 24 weeks), in the absence of plants. There was a significant increase in amorphous phases of iron (Fe) and particularly of aluminum (Al) to the amount of 0.13 g kg ^–1 for Fe and 0.16 g kg ^–1 for Al in the 0-0.05 m layer of the column and 0.22 g kg ^–1 for Al in the 0.05-0.10 m layer. These values account for 6 % of the total Fe, and 27 % of the total Al added as RD in the column. Spectral features in the visible-near infrared-short wave infrared (VIS-NIR-SWIR) and mid-infrared (MIR) range, as well as X-ray diffraction (XRD) scans, were inconclusive because of the small signal-noise ratio of the newly precipitated phases. Selective chemical methods targeted to specific soil pools (precipitated, adsorbed, and leached) were more sensitive to capture the new amorphous phases resulting from the RD dissolution. This study contributes to understanding the effects of RD on the availability of ions and the possibility of amorphous oxides precipitating in the soil. In addition, it helps identify other effects associated with using RD, such as changes in the pH, cation exchange capacity (CEC), and nutrient availability.

Among the various repositories of soil spectral data, the Brazilian Soil Spectral Library (BSSL, https://bibliotecaespectral.wixsite.com/english), created and maintained by the GeoCiS research group, is representative of the pedodiversity of the region, since it combines soil spectra from agricultural and environmental research. The BSSL database contains 16,084 observations with soil-harmonized surface layer physicochemical and spectral data in the visible, near-infrared, short-wave infrared (Vis-NIR-SWIR, 350–2,500 nm) and mid-infrared (MIR, 4,000–600 cm-¹) ranges from all 26 Brazilian states and the Federal District. The idea of creating the BSSL was born in 1995, completed in 2019 and opened to users in 2023. This database is currently available online at https://zenodo.org/records/8361419. During oppening process, data filtering was performed to ensure reliable and valuable information provided to society. Then consistency and quality assessments were executed using Pearson's correlation and the Cubist algorithm in the R environment. Modeling analysis revealed the robust predictive power of the spectral database, facilitating the modeling of key soil attributes. An open-access BSSL will help researchers validate their results by comparing measured data with predicted data, enabling the development of new models or the improvement of existing ones. The BSSL is a globally significant spectral library due to its broad coverage and representation of different tropical soil classes. Soil spectral data can help governments and corporations by providing information to decision-makers regarding the conservation or exploitation of natural resources to monitor soil health.

Unconventional Food Plants (UFP), still little explored due to the lack of knowledge of their properties and forms of use, began to be inserted in the menu of the Brazilian population to obtain nutrients and bioactive compounds that promote good health effects. Among the range of specimens, we have Chaya (Cnidoscolous aconitifolius) a leafy vegetable little studied, which has a high content of minerals and vitamins, besides containing significant protein values. Therefore, the aim of this article is to evaluate the nutritional composition, presence of bioactive compounds and antioxidant capacity of this fresh PANC and submitted to different cooking methods. The most significant protein result was found in the dehydrated leaf (25.70 ± 2.10 mg/100g), on the other hand, the bleached leaf showed a higher amount of phenolics (11.47 ± 1.08 mg/g), and also presented 130.44 ± 41.77mg/g flavonoids, although there is 188.22 ± 25.71mg/g of this nutrient in the fresh leaf, there is no great loss when submitted to the heat source. In relation to antioxidant capacity, there was a reduction of 150.45 ± 0.36µM Trolox/g in ABTS in bleached leaf, and 21.42 ± 0.43µM Trolox/g in FRAP in fresh leaf, but when compared to bleached leaf there were minimal losses, resulting in 20.57 ± 0.49µM Trolox/g. It was possible to conclude that the cooking methods, in order to decrease cyanogenic glycoside levels, they were satisfactory, besides being similar and even exclusive results when compared to the literature, are expressive values, especially when we intend to use them in the form of additional ingredients, in order to promote nutritional fortification and reduce food oxidation.