Restoring Productivity to Leveled Land
1961
Reuss, J. O. | Campbell, R. E.
Field and greenhouse fertilizer tests on subsoils of the Yellowstone Valley which had been exposed by land leveling operations indicate that these subsoils are very deficient in N and P. This conclusion is substantiated by soil analyses. In the greenhouse, yields of barley on untreated subsoil were low, but excellent yields resulted when both N and P were supplied. Nitrogen alone was not effective. Excellent yields of corn were obtained in the field when adequate N and P were supplied or where heavy rates of manure were plowed down. Field response to N alone was good but generally less than that obtained by the combination. Phosphorus used alone did not increase crop yields. Neither physical properties nor minor elements were found to be limiting.
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