In the 1990s, several studies revealed that corn ethanol had a net energy selector 1lossgainFor example, in dry mill ethanol plants, a total energy of 69,616 Btu (British thermal units, a common energy measurement) is used to produce 1 gallon of ethanol. If ethanol can provide 76,330 Btu per gallon, what is the net energy yield for one gallon of ethanol?73,330 Btu–6,714 Btu1.10 Btu6,714 BtuStill, despite its relatively low net energy yield compared with other fuel energy resources, corn ethanol has largely stayed competitive in the U. S. marketplace because of selector 1its low net energy yieldgenerous government subsidiesits efficient use of croplandHowever, its notable increase in net energy yields in recent years has provided proponents of corn ethanol with reason to keep it in the energy market. Which of the following could have contributed to this notable increase? Check all that apply. Energy consumed to make corn ethanol has been steadily increasing since the 1970s. Corn production per pound of fertilizer has increased steadily since the 1970s.