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 Miner, G. Articles by Kamprath, E. Search for Related Content PubMed Articles by Miner, G. Articles by Kamprath, E. Agricola Articles by Miner, G. Articles by Kamprath, E.

Reactions and Availability of Banded Polyphosphate in Field Studies¹

ABSTRACT

The concentration of fertilizer P from both superphosphate and polyphosphate decreased rapidly with increasing lateral distance from the band. Aluminum phosphate and lesser amounts of Fe phosphates were the soil reaction products formed with essentially no difference between the two P materials. A higher proportion of the condensed phosphate ions were in the difficultly extractable form as compared with the orthophosphate ions, indicating that the condensed phosphate ions are held more strongly. The apparent hydrolysis of condensed phosphates increased with increasing lateral distance from the center of the band. Hydrolysis was greater in the Lynchburg, a low P-fixing soil, than in the Georgeville, a high P-fixing soil.

Polyphosphate was as effective as superphosphate in supplying P for plant growth. The residual effectiveness of the polyphosphate was similar to that for superphosphate. Although condensed phosphate ions are held more strongly than orthophosphate by soil materials, there appears to be no difference in their effectiveness as sources of P for plants.

¹ Contribution from the Department of Soil Science, North Carolina State Univ. Agr. Exp. Sta. Published with the approval of the Director as Paper no. 3003 of the Journal series. Taken in part from the Ph.D. dissertation of the senior author. Presented before Div. S-4, Soil Science Society of America, Nov. 14, 1968.

² Former Graduate Student and now Visiting Assistant Professor of Soil Science, Int. Soil Fertility and Evaluation Project, USAID Mission, c/o American Embassy, San Jose, Costa Rica; and Professor, respectively.

Received for publication May 13, 1971. Accepted for publication July 28, 1971.