Distribution of Above Ground Biomass in Corn Stover

Corn stover has been suggested as an ideal strategic feedstock for the bioenergy program because of its abundance and its underutilization at the present time. A key issue that needs addressing is how to harvest and process corn stover to maximize its quality as a fuel (or industrial feedstock), minimize material losses, minimize environmental impacts, and improve handling efficiencies is a key issue that needs to be addressed. Development of strategies/systems for the postharvest handling of corn stover involves quantifying what corn stover biomass is available over time after physiological maturity of the grain has been reached. It also involves understanding how the biomass is distributed in the different above ground components of the corn plant. The objectives of this investigation was to measure the allocation of biomass to above ground components of the corn plant over time and to develop relationships for estimating total above ground corn plant biomass through simple corn plant dimensional measurements. Above ground biomass distribution for two corn cultivars (Pioneer 32K61 and 32K64 Bt) was studied in standing plants from roughly two weeks before grain physiological maturity until four weeks after the actual grain harvest from other plots in the field. Over the monitoring period, the amount of dry matter in stover averaged 50% of the total dry plant material with stalks comprising 50% of the stover dry matter at the time grain was harvested. Validity of the 1:1 stover dry matter to grain fresh weight was confirmed when grain had moisture contents in the harvest range. Such precondition has not been clearly emphasized in the literature. Regression equations using stalk diameter and plant height derived to estimate the green weight and dry matter of the corn plant above the ground had a maximum R2 of 0.75.