Predicting soil C changes after pasture intensification and diversification in Brazil

Author(s)

Damian, Junior Melo ^[1] ; Matos, Eduardo da Silva ^[2] ; Carneiro e Pedreira, Bruno ^[2] ; de Faccio Carvalho, Paulo Cesar ^[3] ; Premazzi, Linda Monica ^[4] ; Williams, Stephen ^[5] ; Paustian, Keith ^[5] ; Pellegrino Cerri, Carlos Eduardo ^[1]

Affiliation

^[1] Univ Sao Paulo, Luiz de Queiroz Coll Agr, BR-13418260 Piracicaba, SP - Brazil

^[2] EMBRAPA, BR-70770901 Brasilia, DF - Brazil

^[3] Univ Fed Rio Grande do Sul, Dept Anim Sci, BR-91540000 Porto Alegre, RS - Brazil

^[4] Inst Zootecnia, BR-13380011 Nova Odessa, SP - Brazil

^[5] Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 - USA

• Document type: Journal article
• Source: CATENA; v. 202, JUL 2021.
• Web of Science Citations: 1

Abstract

Globally, poorly managed pasture can contribute to increasing greenhouse gas (GHG) emissions. In Brazil, sustainable management systems are being proposed to reduce carbon dioxide (CO2) emissions and increase the soil C stock under degraded pasture. However, despite the potential benefits in the adoption of sustainable management systems, few studies have been carried out seeking to analyze their long-term effects on the soil C cycle. In this study, we used the DayCent model to simulate the effects of converting poorly managed pastures (PMP) to more-intensive and diversified systems of pasture management {[}fertilized pasture (FP), integrated crop-livestock (ICL) and integrated livestock-forest (ILF)] on long-term soil C stocks and microbial biomass C (MBC). We also evaluated the effects of different pasture management scenarios for FP (fertilization frequency), ICL (time of implementation of the crop phase) and IFL (spacing between the tree rows). The DayCent model estimated that the conversion of PMP to FP, ICL and ILF increases the soil C stocks by 0.95, 0.04-0.70 and 0.16 Mg ha(-1) yr(-1), respectively. Similarly, the MBC contents also increased with conversion, mainly for ICL and ILF. In addition, the fertilization of the pasture every year (FP), the implementation of the crop phase within two years (ICL) and the spacing between the tree rows of 15 m (ILF) showed the highest soil C stocks and MBC contents. FP, ICL and IFL were also GHG sinks of 43, 57 and 116 Mg CO(2)eq ha(-1), respectively. These results can help national initiatives associated with the recovery of degraded pasture in Brazil. (AU)

• FAPESP's process: 18/21261-0 - Prediction of the alterations in carbon cycling induced by the intensification and diversification of pasture management systems in Brazil
• Grantee: Júnior Melo Damian
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 17/15331-3 - Changes in cycling and accumulation of C induced by intensification and diversification of the pasture management system
• Grantee: Júnior Melo Damian
• Support Opportunities: Scholarships in Brazil - Doctorate