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dc.contributor.advisorHaby, Vincenten_US
dc.contributor.advisorCothren, J. T.en_US
dc.creatorChessman, Dennis Johnen_US
dc.date.accessioned2004-09-30T02:05:16Z
dc.date.available2004-09-30T02:05:16Z
dc.date.created2003-12en_US
dc.date.issued2004-09-30
dc.identifier.urihttp://hdl.handle.net/1969.1/494
dc.description.abstractAcid soils limit the growth of aluminum-(Al) sensitive crops such as alfalfa (Medicago sativa L.). Management of acid subsoils can be difficult due to physical and economic constraints. Field experiments were conducted at two locations to evaluate the effectiveness of surface-applied gypsum and a flue gas desulfurization by-product for reducing the toxic effects of acid subsoils on alfalfa. The materials were applied at rates of 0, 5, 10, and 15 Mg ha-1. In addition, a glasshouse experiment was conducted that used 0, 5, and 10 Mg ha-1 of gypsum only. Field studies were concluded 41 and 45 months after treatment application at the two locations. No effect of material on alfalfa yield or tissue mineral concentration was observed. Also, rate did not affect yield. However, there were differences in plant tissue mineral concentration in several harvests that were related to rate. Soil was sampled periodically to 120 cm and indicated movement of Ca and S into the soil profile to depths of 60 and 120 cm, respectively. Subsoil pHH2O and pHCaCl2 were not affected by treatment. Extractable and exchangeable Al were not reduced by movement of Ca and S into the soil. In the glasshouse study, alfalfa yields and root growth were not affected by gypsum rate. As gypsum rate increased, plant tissue S increased, but K and Mg decreased. Alfalfa roots did not grow below 60 cm, even though there was indication of material movement to 90 cm in the soil. Although sulfur moved to 75 cm, no effect on soil Al was observed. Leachate collected from the bottoms of columns indicated that soil cations were leached as a result of gypsum application. Gypsum and the flue gas desulfurization by-product did not significantly affect the acid soils used in these studies or improve alfalfa growth.en_US
dc.format.extent986862 bytes
dc.format.extent409489 bytes
dc.format.mediumelectronicen_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypetext/plain
dc.language.isoen_USen_US
dc.publisherTexas A&M Universityen_US
dc.subjectalfalfaen_US
dc.subjectsoil acidityen_US
dc.subjectgypsumen_US
dc.subjectaluminum toxicityen_US
dc.titleThe use of gypsum and a coal desulfurization by-product to ameliorate subsoil acidity for alfalfa growthen_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentSoil and Crop Sciencesen_US
thesis.degree.disciplineAgronomyen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameDoctor of Philosophyen_US
thesis.degree.levelDoctoralen_US
dc.contributor.committeeMemberHons, Frank M.en_US
dc.contributor.committeeMemberRouquette, Monteen_US
dc.contributor.committeeMemberKnight, Roberten_US
dc.type.genreElectronic Dissertationen_US
dc.type.materialtexten_US
dc.format.digitalOriginborn digitalen_US


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