Table 11. Yields on stubble land tilled in the spring with the moldboard plow, the double disk and the one-way disk.
Treatment
1959 Yield - Bushels per acre.
1 2 3 4 Av.
Spring plowing 5.5 6.5 4.3 8.8 6.3
One-way disking 8.3 7.1 14.1 8.3 9.5
Double disking 3.1 4.3 9.0 8.6 6.3

Table 12. Summary of yields on stubble land tilled in the spring with the moldboard plow, the double disk and the one-way disk, - 1955 - 1959.
Year
Average yield in bushels per acre.
Spring plowing One-way disking Double disking
1955 22.0 17.6 14.5
1956 14.2 11.5 9.3
1957 18.0 16.7 15.5
1958 19.3 18.7 15.1
1959 6.3 9.5 6.3
Average 16.0 14.8 12.1