• Carbon dioxide in soil air - graph 

        Contributor:Colorado Agricultural College
        Date:1927
        Chart titled "CO2 in Soil Air, Lysimeter 18 inches deep. Average of East and West plots. Legend: alfalfa, clover, corn, fallow."
      • Carbon dioxide in soil air - graph 

        Contributor:Colorado Agricultural College
        Date:1927
        Chart titled "CO2 in Soil Air, Lysimeter 6 inches deep. Average of East and West plots. Legend: alfalfa, clover, corn, fallow."
      • Carbon dioxide in soil air - graph 

        Contributor:Colorado Agricultural College
        Date:1927
        Chart titled "CO2 in Soil Air, Lysimeter 18 inches deep. Average of East and West plots. Legend: alfalfa, clover, corn, fallow."