Eucalyptus tree influence on spatial and temporal dynamics of fine-root growth in an integrated crop-livestock-forestry system in southeastern Brazil

Author(s)

Bieluczyk, Wanderlei ^[1] ; Piccolo, Marisa de Cassia ^[1] ; Pereira, Marcos Gervasio ^[2] ; Lambais, George Rodrigues ^[3] ; Moraes, Moacir Tuzzin de ^[4] ; Soltangheisi, Amin ^{[5, 6]} ; Bernardi, Alberto Carlos de Campos ^[7] ; Pezzopane, Jose Ricardo Macedo ^[7] ; Bosi, Cristiam ^[7] ; Cherubin, Mauricio Roberto ^[8]

Affiliation

^[1] Univ S ao Paulo, Ctr Nucl Energy, Agr Nutrient Cycling Lab, 303 Centenario Ave, BR-13416000 Piracicaba, SP - Brazil

^[2] Fed Rural Univ Rio Janeiro, Dept Soils, BR 465 km 7, BR-23897000 Seropedica, RJ - Brazil

^[3] Natl Inst Semiarid, Dept Water Resources, Francisco Lopes Almeida Ave, BR-58434700 Campina Grande, Paraiba - Brazil

^[4] Fed Univ Technol Paran, Dept Agron Sci, Box 135, BR-85601970 Francisco Beltrao - Brazil

^[5] Univ Lancaster, Lancaster Environm Ctr, Lancaster - England

^[6] Univ Sao Paulo, Ctr Nucl Energy, Agr Isotop Ecol Lab, 303 Centenario Ave, BR-13416000 Piracicaba, SP - Brazil

^[7] Brazilian Agr Res Corp, Embrapa Southeast Livestock, P.O. Box 339, BR-13560970 Sao Carlos - Brazil

^[8] Univ Sao Paulo, Luiz Queiroz Coll Agr, Dept Soil Sci, 11 Padua Dias Ave, BR-13418900 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: RHIZOSPHERE; v. 19, SEP 2021.
• Web of Science Citations: 0

Abstract

Integrated farming systems are promising strategies towards land-use efficiency and sustainable agriculture. The integrated crop-livestock-forestry (ICLF) system stablish complex interactions were synergies or competition depend on the arrangements throughout time and space. Fine root (<= 2 mm) growth dynamics of crops, pasture and trees remains unclear when these species are integrated. We aimed to assess root growth dynamics after Eucalyptus urograndis introduction into an integrated crop-livestock (ICL) system. Previous ICL area was used as a reference. We assessed ICLF 1.9, 4.3 and 7.5 m distances from tree rows, starting the study when trees had three years of age. Eucalyptus rows were spaced 15 m apart and integrated to annual crops and pasture. We evaluated the root growth under two different successional periods: (i) corn cultivation interspaced with palisade grass (Urochloa brizantha); and (ii) a pasture, when palisade grass was grazed. We tracked fine rootlength using the minirhizotron technique, capturing 3200 images scanning up to 70 cm soil depth. Data of photosynthetically active radiation (PAR) transmission, soil bulk density, rainfall and air temperature were used as complementary information to support the discussion. Our results showed that Eucalyptus trees impaired root growth of annual crops cultivated in the interrow position, regardless of distance from the row. From 31 to 80 days after corn germination, root length production in ICLF was reduced by 120-179 cm m(-2).d(-1) along the tree interrow space. For the pasture period, total produced root length density reduced 6% at 1.9 m but increased 25% at 4.3 and 7.5 m, when compared to ICL. Shade of Eucalyptus trees at ICLF 1.9 m position, with PAR transmission mainly below 60%, sharply impaired root growth. Eucalyptus roots represented 12% from total root length produced in ICLF system, and 38% of these roots had positive ectomycorrhizal status. In conclusion, under Eucalyptus trees higher than 20 m, pasture of palisade grass is more adaptable than corn when considering the root growth dynamics of our studied ICLF arrangement. Based on our findings, corn intercropped with palisade grass should not be introduced in future management of the ICLF system, unless part of the trees is chopped to reduce light competition. However, implemented pasture of palisade grass showed belowground synergies with Eucalyptus, increasing root growth in intermediary interrow positions and emerging new fungal symbiosis, which could be playing important functions in soil, as soil carbon storage and nutrient cycling. (AU)

• FAPESP's process: 17/11332-5 - Phosphorus dynamics and its fractions in soils under pasture-sugarcane conversion and intensification in pastureland
• Grantee: Amin Soltangheisi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/09845-7 - Implications of expansion and management intensification on soil ecosystem services
• Grantee: Maurício Roberto Cherubin
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/17927-2 - Growth and decomposition of fine roots and soil quality under integration of agriculture, livestock and forestry systems (São Carlos, SP)
• Grantee: Wanderlei Bieluczyk
• Support Opportunities: Scholarships in Brazil - Doctorate