Assessment of Piata palisadegrass forage mass in integrated livestock production systems using a proximal canopy reflectance sensor

Author(s)

Macedo Pezzopane, Jose Ricardo ^[1] ; de Campos Bernardi, Alberto Carlos ^[1] ; Bosi, Cristiam ^[2] ; Crippa, Paulo Henrique ^[3] ; Santos, Patricia Menezes ^[1] ; Nardachione, Estefania Cereda ^[3]

Affiliation

^[1] Embrapa Pecuaria Sudeste, Empresa Brasileira Pesquisa Agr, POB 339, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Ave Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[3] Univ Sao Paulo, Fac Zootecn & Engn Alimentos, Ave Duque Caxias Norte 225, BR-13635900 Pirassununga, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN JOURNAL OF AGRONOMY; v. 103, p. 130-139, FEB 2019.
• Web of Science Citations: 0

Abstract

Estimates of forage mass can help in decision making for pasture management and stocking rate adjustment in pastoral systems. This study aimed to estimate Piata palisadegrass forage mass under full sun and shaded livestock production systems using vegetation indexes obtained with a proximal canopy reflectance sensor. Pasture canopy reflectance was measured at three fractions of the radiation spectrum (670, 720, and 760 nm). Total forage mass, morphological composition, and leaf area index (LAI) were assessed at the same time as reflectance in all production systems. Reflectance data were used to calculate vegetation indexes (normalized difference vegetation index - NDVI, normalized difference red edge - NDVI\_RE, simple ratio index - SRI, modified simple ratio - MSR, and chlorophyll index) for each assessment. Linear and exponential regression analyses between vegetation indexes and total forage mass, leaf + stem mass, leaf mass, and LAI were performed. The equations generated by these analyses were used to estimate such pasture variables. The best estimates of leaf + stem mass, leaf mass, and LAI were obtained using SRI (R-2 between 0.55 and 0.84) for the full sun systems, MSR (R-2 from 0.67 to 0.93) for the shaded systems, and NDVI (R-2 between 0.65 and 0.91) when all systems were analyzed together. These pasture variables can be estimated by general equations developed for both full sun and shaded livestock production systems. However, total forage mass estimates were less efficient (R-2 of 0.03-0.53), due to differences in canopy structure and senescent material content between production systems. (AU)

• FAPESP's process: 16/02959-1 - Eucalyptus thinning in integration Crop-Livestock-Forest system: effects on microclimate and productivity
• Grantee: José Ricardo Macedo Pezzopane
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/11931-8 - Parameterization and evaluation of mechanistic crop simulation models to estimate Urochloa brizantha cv. Piatã productivity in a silvopastoral system
• Grantee: Cristiam Bosi
• Support Opportunities: Scholarships in Brazil - Doctorate