HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lutz, J. F. Articles by Pinto, R. A. Search for Related Content PubMed Articles by Lutz, J. F. Articles by Pinto, R. A. Agricola Articles by Lutz, J. F. Articles by Pinto, R. A.

Effect of Phosphorus on Some Physical Properties of Soils: I. Modulus of Rupture¹

ABSTRACT

Applications of phosphorus, both as phosphoric acid and as monocalcium phosphate, to three soils were very effective in reducing the hardness of soils as measured by modulus of rupture. Phosphoric acid was more effective than monocalcium phosphate on all three soils. Both sources of P were more effective on Iredell soil, which consists predominantly of montmorillonite with some kaolinite, than on White Store soil, which contains montmorillonite and kaolinite but with some illite. Even though both sources of P produced significant decreases in modulus of rupture on the Georgeville soil, which contained predominately 1:1 clay minerals, the results were not as striking as on the Iredell. The greatest effect per unit of P was produced by the smaller increments, especially by the 50-ppm rate. This is especially important from both agronomic and economic standpoints since 50 to 100 lb/acre are feasible rates.

¹ Contribution from the Soil Science Department, North Carolina Agr. Exp. Sta., Raleigh. Published with the approval of the Director of Research as Paper no. 1860 of the Journal Series.

² Professor of Soil Science, North Carolina Agr. Exp. Sta., Raleigh.

³ Assistant Professor, Facultad de Agronomia, Universidad Central de Venezuela, Maracay, Aragua, Venezuela. (Formerly, Graduate Student at North Carolina State Univ.)

Received for publication August 17, 1964. Accepted for publication March 11, 1965.