Thesis (Ph. D.)--University of Wisconsin--Madison, 1926. / Typescript. With this is bound: The availability of potassium to plants as affected by stable manure / R.P. Bartholomew, reprinted from the Journal of the American Society of Agronomy, vol. 20, no. 1 (Jan. 1928), p. 55-81. Includes bibliographical references (leaves 89-91).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: J. Thomas Sims, Agriculture and Natural Resources. Includes bibliographical references.

Laboratory incubation was conducted for 120 days to study the fate of phosphorus in poultry (PM), cattle (CM) and goat manures (GM). Phosphorus mineralized from manure was dependent on total P, Al and Fe content. Manures improved P availability in the order: PM > CM > GM; however, the highest amount of P was fixed or immobilized between 10 and 70 days of incubating with CM and GM. Fixation and immobilization of mineralized P from poultry manure was negligible probably due to the high total P and the low amount of Al and Fe. Generally, manure application reduced the ability of the soil to fix P. More than 90% of the manure P was either immobilized or fixed by the soil. The relationship between the amount of P released and time was cubic. Improvement of the C:P ratio of CM and GM would be an option to enhance their agronomic use as fertilizer P source.

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Gaseous movement in soil varies with soil's physicochemical properties and biochemical oxygen demand. Diffusivity patterns of four different types of soil (sand, silt, sandy silt, and clay) were examined and sand have shown the highest rate of diffusivity increase with the decreasing soil moisture content. Raw cow manure was then added to the sandy soil at four different rates 0, 20,40, and 80 Mg/ha. Depletion of soil oxygen and changes of carbon dioxide and ammonia for different concentrations were compared against the control. The oxygen depletion or carbon dioxide and ammonia accumulation reached the highest level at initial 16 hour followed by gradual reversal to a steady state. A significant amount of oxygen depletion was noticed with the different concentration levels. Oxygen depletion had shown an oscillatory behavior towards zero. Among different concentrations that of 40 Mg/ha showed the highest oscillatory behavior, but the shortest time was required to recover its original oxygen level. Thus the 40 Mg/ha application of organic matter is seems to be the optimum level for sandy soil.

Thesis (Ph. D.)--Washington State University, August 2009. / Title from PDF title page (viewed on July 31, 2009). "Department of Biological Systems Engineering." Includes bibliographical references.