Biodiesel from Algae compared with Ethanol from crops

USA Land Area Acres Square miles Area (Texas=1)
Total 3775m5,900,0007.7
Crop land 450m 720,000 2.6
Pastures 580m 906,000 3.2
Urban land 66m 103,000 0.37
"Unusable" Land 2700m4,171,0005.7
Algae ponds 60m 90,000 0.3 assuming 2,500 gal/acre
Algae at theoretical max 10m 15,000 0.15 assuming 14,000 gal / acre
corn based ethanol 560m 900,000 3.2assuming 300-400 gal/acre
switchgrass today 300m 450,000 2
switchgrass ethanol at theoretical max 114m 178,000 0.5