Deep soil carbon stock, origin, and root interaction in a tropical integrated crop-livestock system

Author(s)

Sarto, Marcos V. M. ^[1] ; Borges, Wander L. B. ^[2] ; Sarto, Jaqueline R. W. ^[3] ; Rice, Charles W. ^[1] ; Rosolem, Ciro A. ^[3]

Affiliation

^[1] Kansas State Univ, Dept Agron, Manhattan, KS 66506 - USA

^[2] Agron Inst IAC, Adv Res Ctr Rubber Tree & Agroforestry Syst, Votuporanga, SP - Brazil

^[3] Sao Paulo State Univ, UNESP, Ave Univ 3780, BR-18610034 Botucatu, SP - Brazil

• Document type: Journal article
• Source: AGROFORESTRY SYSTEMS; MAY 2020.
• Web of Science Citations: 1

Abstract

Integrated crop-livestock systems (ICLS) with fast-growing tree plantations are an environmentally sound approach for agricultural production. Soil carbon stocks can be increased under these systems, but there is no information on the relative contributions of the pasture and the trees in building soil C in tropical regions. This study aimed to investigate C storage, origin, and roots sequestration in the soil profile (1.0 m) in a pasture-forest system. The study was conducted in a 6-year-old ICLS in whichEucalyptus(C-3) were introduced into a palisade grass pasture {[}Urochloa brizantha(Hochst. Ex A. Rich.) R. Webster `Marandu', C-4]. Samples were collected at four locations perpendicular to theEucalyptusplanting line: 0 (planting line), 2.0, 4.0, and 6.0 m (middle of the plot). A monoculture palisade grass pasture was included for comparison. The insertion ofEucalyptusin the pasture modified the quantity and distribution of grass above and belowground. Forage root and shoot biomass were lower in the integrated system compared to the monoculture pasture, mainly nearEucalyptus. However, plant C sequestration in the ICLS was 68% higher than in the monoculture pasture, due to the C accumulated by aboveground trees biomass. Overall, monoculture pasture had higher soil C-4-C stocks at the 0-0.20 m depth, while integrated system withEucalyptusstored more C-3-C in deeper soil layers (0.60-1.0 m) nearEucalyptus. Soil C stock increased in both systems, but the contribution ofEucalyptuswas deeper in the soil profile, while the grass contribution was greater in the upper 0.20 m soil layers. (AU)

• FAPESP's process: 16/14323-4 - Microbial activity in integrated eucalyptus and Urochloa
• Grantee: Marcos Vinicius Mansano Sarto
• Support type: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/10656-3 - Eucalyptus contribution for soil organic matter in integrated
• Grantee: Marcos Vinicius Mansano Sarto
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/08664-5 - Carbon budget and soil organic matter quality in crop-livestock integration systems
• Grantee: Ciro Antonio Rosolem
• Support type: Regular Research Grants