**7. Acronyms**

SOR: Slaughterhouse organic residue

SMF: Synthetic mineral fertilizer

N: Nitrogen

C: Carbon

TOC: Total organic carbon

MAOC: Mineral‐associated organic carbon

POC: Particulate organic carbon

C‐OXP: Permanganate oxidizable organic carbon

C‐HW: Hot water extractable organic carbon

GHG: Greenhouse gases

The increase in C‐CO2 emissions with SOR addition produced an initial increment and variability in TOC (**Figure 6**). This variability suggests disturbance in the microorganisms' activity through the SOR addition. The SOR applications provided accumulated emissions of 1.28, 1.56, 1.58, 1.63, 1.88 and 2.79 Mg ha−1 C‐CO<sup>2</sup> and fixations of 0.24, 1.52, 1.36, 1.92, 1.92 and 3.04 Mg ha−1 TOC (reduced values from the initial TOC) in the soil after the 125‐day incubation period. These results indicate that, although there is a pronounced flux of C‐CO2 with higher SOR applications, the TOC levels also increased. The TOC fixation was higher than the C‐

Therefore, SOR application can be considered a promising strategy in order to provide soil C

The applications of poultry and pork slaughterhouse waste increased crop productivity, especially in T5 (50% SOR + 50% SMF). The C labile pools (C‐HW, C‐OXP and POC) were higher in the treatments with elevated SOR applications (50% and 75%), thereby increasing soil quality and sustainability. In addition, fertilization with SORs demonstrated to be an alterna‐

We thank the Comissão de Aperfeiçoamento de Pessoal do Nível Superior (CAPES) for our graduate fellowships and the Agrisus Foundation for providing financial aid, which allowed

tive to minimize the costs and use of mineral fertilizers and increase C sequestration.

sequestration, affecting directly the quality and productivity of the system.

CO2 flux for the 4, 8 and 16 Mg ha−1 rates.

236 Organic Fertilizers - From Basic Concepts to Applied Outcomes

**5. Conclusions**

**6. Acknowledgements**

**7. Acronyms**

N: Nitrogen

C: Carbon

for the publication of this chapter.

SOR: Slaughterhouse organic residue

MAOC: Mineral‐associated organic carbon

C‐OXP: Permanganate oxidizable organic carbon

SMF: Synthetic mineral fertilizer

TOC: Total organic carbon

POC: Particulate organic carbon

C‐CO2: Carbon emitted as carbon dioxide.
