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Effect of Soil Depth and Plant Age on 32Phosphorus Uptake by Corn and Sorghum 1
Author(s) -
Lavy T. L.,
Eastin J. D.
Publication year - 1969
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1969.00021962006100050008x
Subject(s) - sorghum , loam , agronomy , zea mays , sorghum bicolor , poaceae , sweet sorghum , biology , soil water , ecology
Carrier‐free H 3 32 PO 4 was injected into a Sharpsburg silty clay loam soil at depths of 15, 30, and 61 cm when corn ( Zea mays L., var. ‘Nebraska 202’) and sorghum ( Sorghum bicolor (L.) Moench, var. ‘Nebraska 505’) plants were 23, 39, and 59 days old. At the 23‐day age most 32 P was taken up by roots in the upper 15 cm. Corn roots penetrated to a 61 cm depth earlier than sorghum roots. As the season progressed, sorghum lateral root activity at the 30 and 61 cm soil depths became important. Following the radioactive P injections when plants were 59 days old, sorghum took up more 32 P than corn. Plant age or depth of injection had little effect on the 32 P contributed by roots at varying distances from the source. Roots which extended laterally beyond 66 cm contributed little to the P nutrition of either corn or sorghum grain. Both corn and sorghum had root systems that penetrated to a depth of 152 cm and extended laterally 238 cm.