Residual effects of chloride application in a corn-wheat rotation
1989
Schumacher, W.K. | Fixen, P.E.
Significant correlations have been noted between soil Cl, Cl uptake, and yield response in spring wheat (Triticum aestivum L.). Little information exists, however, concerning the residual value of Cl, especially in subhumid areas. Therefore, a study was conducted to determine residual effects of Cl application on soil Cl levels and on associated crop yield in a wheat-corn (Zea mays L.) rotation. Six Cl rates ranging from 0 to 510 kg ha-1 were applied as KCl (muriate of potash) to a soil (Udic Haploboroll) with an initial soil-Cl content of 19 kg ha-1 in the upper 60 cm. A corn-spring wheat rotation was practiced between two adjacent sites. Soil Cl levels were measured after the first three seasons at five depth increments to a final depth of 120 cm. Maximum Cl concentrations following the first growing season occurred at approximately 50 cm. By the beginning of the third growing season, most of the Cl had leached below 120 cm. Deep sampling to 3 m after the third growing season indicated maximum Cl accumulation between 1 and 2 m. A positive response of spring wheat to added Cl was observed for the first two growing seasons. Factors contributing to the removal of Cl from the upper 120 cm include above-average precipitation and large precipitation events. Chloride soil testing is recommended prior to the establishment of a Cl-responsive crop in regions where responses have been verified.
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