J. Prummel

Fertilizer placement experiments

J. Prummel, 1957, Plant and Soil.

Effect of soil structure on phosphate nutrition of crop plants

J. Prummel, 1975 .

Placement of a compound (N.P.K.) fertilizer compared with straight fertilizers

J. Prummel, 1960 .

Optimum phosphate and potassium levels in potato tops

J. Prummel, PA Barnau-Sijthoff, 1984, Fertilizer research.