This study investigated soil carbon and nitrogen stocks and quality of soil organic matter in an Eutric Haplic Cambisol four years after the conversion of degraded pastures into silvopastoral systems in the Brazilian Cerrado. The integrated production systems were composed of marandu grass (Urochloa brizanta) and Eucalyptus cloeziana or Eucalyptus urograndis. These systems were compared with areas of regenerating stratum and native vegetation of the Cerrado biome. A randomized statistical design was used, and soil chemical and biological attributes and soil CO₂ efflux were evaluated (p < 0.05). After four years of implantation, soil carbon and nitrogen stocks increased in silvopastoral systems in relation to regeneration stratum, but were still lower than those in native vegetation. The chemical and granulometric soil fractionations indicated that carbon was protected in the most stable soil organic matter fractions (humin and silt + clay). There was an increase in soil microbial carbon during the rainy season and the metabolic quotient during the dry period. The deposition of plant material and soil tillage in silvopastoral systems composed of marandu grass (Urochloa) and Eucalyptus cloeziana contributed to an increase in soil microbial carbon at the 10–20 cm soil layer. The soil CO₂ efflux, during the rainy and dry seasons, was similar between both silvopastoral systems and native vegetation, probably indicating greater diversity of organisms and roots in these systems than in regeneration stratum. We conclude that the introduction of integrated systems improved soil quality, allowing greater protection of soil organic matter.

这项研究调查了巴西Cerrado地区退化的牧场转换为牧草牧系统后的四年，在一个Eutric Haplic Cambisol中调查了土壤碳和氮储量以及土壤有机质的质量。综合生产系统由马兰杜草（Urochloa brizanta）和cloucaiana桉树或urograndis桉树组成。将这些系统与Cerrado生物群落的再生地层和原生植被区域进行了比较。使用了随机统计设计，并且土壤化学和生物学特性以及土壤CO ₂评估外排（p <0.05）。植入四年后，林牧系统中的土壤碳和氮储量相对于再生层增加，但仍低于天然植被。化学和粒度土壤分馏表明，碳在最稳定的土壤有机质组分（腐殖质和淤泥+粘土）中得到了保护。在雨季，土壤微生物碳含量增加，而在干燥期，代谢商含量增加。在由马兰杜草（Urochloa）和克氏桉属组成的牧草系统中，植物材料的沉积和土壤耕作促使土壤微生物碳在10–20 cm土层增加。土壤CO ₂牧牧系统和原生植被在雨季和干旱季节的外流相似，这可能表明这些系统中生物和根的多样性比再生地层更大。我们得出结论，采用集成系统可以改善土壤质量，从而更好地保护土壤有机质。