Response of Corn to Zn in Ortho- and Pyrophosphate Fertilizers, as Affected by Soil Temperature and Moisture1
- P. M. Giordano and
- J. J. Mortvedt2
Performance of ortho- and polyphosphate fertilizers as carriers of Zn for crops has varied in field trials, suggesting that an interaction might exist with climatic conditions. The purpose of this investigation was to determine the effects of both soil temperature and moisture regimes on the uptake of Zn and P by corn (Zea mays L.) from ZnSO4 granulated with ammonium ortho-and polyphosphate fertilizers and applied to Nolichucky scl (pH 7.6), a Typic Paleudult soil. In a series of greenhouse experiments, corn grown under various soil temperature (16 to 32 C) and moisture regimes (0.3 to 0.15 atm) showed a marked reduction in dry matter yield, as well as in Zn and P uptake, at low temperature, but varying soil moisture levels had little effect. Uptake of Zn was greater when triammonium pyrophosphate rather than monoammonium phosphate was the source of applied P, but uptake of P from the two P sources was comparable. Although lower Zn uptake appears to be a function of depressed growth under cool soil conditions, it is likely that deficiency arises because early Zn requirements cannot be met when the availabale Zn supply is low. Uptake and yield results further suggest that early growth retardation sometimes attributed to Zn deficiency during cool springs also may be related to suppression of P uptake.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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