Radiation Use Efficiency of Forage Resources: A Meta-Analysis

DRUILLE, MAGDALENA; OESTERHELD, MARTÍN; OYARZABAL, MARIANO

AGRONOMY JOURNAL

AMER SOC AGRONOMY

Año: 2019 vol. 111 p. 1770 - 1778

0002-1962

Forage production is increasingly monitored through modelsbased on remote sensing. Radiation use efficiency (RUE) is akey input to these models. However, no study has synthesizedthe published values of RUE of forage resources. Our objectivewas to quantitatively synthesize through a meta-analysis thevariation of RUE of forage resources and its main controls. Wegathered 496 RUE values and assessed their variation accordingto genotype, resource availability and phenological stage. MeanRUE was 1.93 ± 1.2 g of dry matter (DM) per megajoule of interceptedphotosynthetically active radiation (IPAR) (±SD). TheRUE was most responsive to genotype and to direct and indirectmanipulations of resource availability. Within genotype treatments,mean effect size of C4 species identity, cultivar identityand C3 species identity was 61, 58, and 42%, respectively. Withinresource availability treatments, mean effect size was 43% for Nfertilization, 40% for shading and inter-annual environmentalvariation and 23% for irrigation and defoliation frequency. Forthe phenology treatment, mean effect size of reproductive vs.vegetative stage did not differ from zero. This large variabilityimplies a challenge to select RUE values as input to estimateproductivity through plant-growth models, such as those basedon remote sensing, but also highlight the margin for increasingRUE through breeding and management practices