Between 1974 and 1983, intertemporal cost efficiency for u.s. field crops increased about 1.4 to 1.2% percent for corn, soybeans, and wheat and .2% per year for cotton. competitive advantage in 1983 was held by central Illinois and north central Iowa in corn, central Illinois in soybeans, the...

The total factor productivity index for u.s. wheat was 1.5% per year between 1974 and 1983. The conservation tillage productivity index for u.s. wheat was about 1.1% per year during this time period, or about 75% of the T.F.P. North Dakota and Washington were equal in competitive advantage in...