Rapeseed stubble as resource for bioenergy and biorefineries. Effect of genotype and cultivation conditions on chaff and stalk biomass and quality

WASSNER D.; GAGLIARDI REOLON M. B.; GOMEZ N.V.; LOPEZ CESAR; RONDANINI D.P.

Agronomia y Ambiente

FAUBA

Lugar: Buenos Aires; Año: 2020 vol. 40 p. 88 - 99

The abundance and low price of the residual biomass of extensive crops makes them an attractive raw material for bioenergy and biorefineries. Residual biomass (stubble) is made up of biomass from different organs and may differ in its chemical composition. In rapeseed, the stubble is made up of the stalks and the pericarp of the siliques (chaff) and their characteristics have not been analyzed separately up to the present. Thus, it is impossible to determine the possible best uses for each fraction of the stubble based on its composition. This work aims to evaluate the quantity and composition of stalks and chaff biomass of 13 rapeseed genotypes in a variety of growing conditions, to test the following hypotheses: 1) the amount of stubble biomass per area is higly variable and cannot be estimated from grain yield, 2) the stubble-to-grain and the chaff-to-stalk ratios change with genotype and growth conditions, 3) the chemical composition of chaff and stalk is different, which justifies a separate use. The stubble biomass was between 2-6 t ha-1 according to genotype and cultivation conditions. The chaff-stalk ratio was not stable and ranged from 0.8-2.2. The stalk biomass is better to produce energy, due to its high caloric power (17-18 MJ kg-1) and low ash content (6%), while chaff have less cellulose (