Applied fertilizer restored grain sorghum ( Sorghum vulgare ) yields on 10‐cm cut Pullman silty clay loam to 93% of those obtained on uncut soil. On 20‐, 30‐, and 41‐cm cuts, yields were restored to 87% of those on uncut soil. Soil water storage, water use, and water‐use efficiency data revealed that differences in soil water storage and use were responsible for differences in yield when fertility was not limiting. Topsoil removal decreased and fill increased water‐holding capacity of the soil profile. Topsoil removal decreased water loss from fallowed soil, but fill had little effect. N was the only added nutrient required to produce highest yields obtained under limited moisture conditions in this study. Inadequately fertilized treatments used less water than adequately fertilized ones, but water‐use efficiency was greater where plant nutrients were adequate.
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HAROLD V. ECK (1969) studied this question.