The carbon stock (C Stock) is a key soil attribute, especially in areas under degradation. The objective of this study was to map the C Stock and other physical and chemical attributes on the soil surface of a micro-watershed located in the Gilbués Desertification Nucleus and to calibrate pedometric functions to map them, applying spectra obtained by Diffuse Reflectance Spectroscopy (DRS) in the near-infrared (NIR) region. This study was developed in the Piripiri Stream Micro-watershed (PSMW), which presents different levels of degradation. A total of 214 composite soil samples were collected from the 0–0.10 m depth layer. Spectral and laboratory analyses were performed following traditional methods. The results from 100 samples were subjected to descriptive analysis, pedometric modeling, and geostatistics, while the remainder were used exclusively for the prediction and modeling of the predicted attribute maps. C Stock ranged from 0.3 to 11%, with the highest values associated with the least sandy sites. We assert that stakeholders, including government agencies, could utilize DRS for mapping main soil attributes, such as C Stocks, soil granulometry, or total organic carbon, in regions characterized by similar parent material and soil properties. This application can support informed decision-making regarding land management in extensive areas facing soil threats.

As pastagens contribuem de maneira significativamente para os meios de subsistência e serviços ecossistêmicos e são consideradas como principal fonte de fibra e nutrientes animal. Este trabalho teve como objetivo avaliar a variabilidade espacial dos teores de cálcio, alumínio, acidez potencial, fósforo e carbono orgânico total, bem como sua correlação com a produtividade de uma pastagem de capim Mombaça em um Neossolo Litólico Distrófico no município de Floriano-PI. O trabalho foi realizado na fazenda experimental do Colégio Técnico de Floriano (CTF), pertencente à Universidade Federal do Piauí. A área avaliada corresponde a 2 ha cultivada com capim Mombaça (Panicum Maximum cv. Mombaça) irrigado com sistema de aspersão. A amostragem do solo foi realizada nos pontos de cruzamento de uma malha, com intervalos regulares de 10 metros em uma área de 0,54 ha, perfazendo o total de 54 pontos amostrais. Para análise dos dados foram utilizados os métodos da estatística clássica, análise de correlação, análise geoestatística e técnica de interpolação de dados. O diagnóstico da fertilidade do solo mostra o fósforo como o mais deficiente seguido do cálcio. Os valores de alumínio e acidez potencial mostram-se adequados ao bom desenvolvimento do capim Mombaça. A variabilidade dos mapas mostra a heterogeneidade da distribuição e concentração dos elementos no solo, o que possibilita a aplicação de fertilizantes em taxas variadas visando sua homogeneização. A produtividade teve forte relação com os teores cálcio e fósforo. O uso da geoestatísticas podem ser usadas para otimizar áreas de produção capim Mombaça em Neossolos Litólicos.

The Gilbués desertification perimeter encompasses approximately 6,200 km2 in northeastern Brazil. It is widely recognized for its advanced stage of soil degradation. Its landscape is characterized ...

The increasing demand for food has driven the conversion of native areas into agricultural land, a transformation with significant implications for soil carbon (C) balance due to current cultivation systems. Developing and implementing cropping systems that promote C accumulation is crucial for maintaining agricultural sustainability. In this context, this study aimed to understand land management in the state of Piauí, located within the Brazilian Cerrado, investigating biological indicators of soil quality in a cultivation chrono sequence on an Oxisol, in order to support the development and implementation of cropping systems that promote carbon accumulation. The chrono sequence comprised four areas: one native area and three cultivated areas for 12, 18, and 24 years. The biological quality indicators included soil organic carbon (SOC), microbial biomass carbon (MBC), basal soil respiration (C-CO₂), microbial quotient (qMic), and metabolic quotient (qCO₂), as well as C stock and CO₂ sequestration across the 0.0-10, 10-20, 20-30, 30-40, and 40-50 cm soil layers. The results showed no significant differences among areas for MBC, qMic, and qCO₂, but the SOC stock, C-CO₂, and C stock were increased with longer cultivation periods. CO₂ sequestration rates were 0.96, -0.06, and 1.69 Mg ha-¹ year-¹ in the areas cultivated for 12, 18, and 24 years, respectively. Overall, the duration of cultivation enhanced microbial activity and C stock, contributing to CO₂ sequestration compared to the native area. Our findings evidenced that research focusing on region-specific management systems are essential to ensure the long-term agriculture sustainability, since each region has distinct environmental and climatic conditions that directly influence the outcomes of implemented agricultural practices.