Fertilizing Cotton with Recovered P from Swine Manure.
Ariel Szogi1, Philip Bauer2, and Matias Vanotti2. (1) 2611 W Lucas St, USDA-ARS-NPA-SPNRU, USDA-ARS, Coastal Plains Soil Water & Plant Res. Ctr., Florence, SC 29501, (2) 2611 W Lucas St, USDA-ARS Coastal Plains Soil Water & Plant Res. Ctr, Florence, SC 29501
A new treatment technology has been developed to recover soluble P from liquid swine manure. Our objective was to compare P availability and leaching distribution in soils using the recovered P from swine wastewater (31% P2O5) compared with triple superphosphate (46% P2O5) and broiler litter (2.6% P2O5) P sources. A column (15-cm by 76-cm) study was conducted in a greenhouse with Uchee sand (loamy, siliceous, thermic, Arenic Paleudult) soil. Experiments were performed in duplicate; each one with and without cotton plants. The three fertilizer P materials were mixed within the first top 15-cm of the columns at a rate of 0.14 g P per column before planting cotton. Columns were leached with tap water (2.0 liters) weekly for six weeks. At the end of the experiments, cotton plants were analyzed for P concentration. Fertilizing cotton with recovered P resulted in the same plant P concentration as plants fertilized with TSP or broiler litter. Soil P availability (Mehlich 3) was similar for the columns with and without cotton plants. Movement of available soil P below 15-cm depth (above which the fertilizer materials were placed) occurred only for columns with TSP. Available soil P concentrations did not differ among the three P fertilizer materials at depths below 22.5 cm. Results suggest the recovered P from swine waste water can be useful as a readily available P source for cotton, yet it is less prone to leaching than TSP.