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Effect of Soil Type and Fertilizer Application Timing on Phosphorus Leaching From Gypsum-Treated Agricultural SoilsCox, Kristiana 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Phosphorus is an essential plant nutrient and an important contributor to the eutrophication of aquatic ecosystems. Studies have shown that gypsum (CaSO4∙H2O) applications can potentially reduce phosphorus export from agricultural fields. Most studies have examined the effect of gypsum application rates on treatment effectiveness, but limited research has been conducted to determine how the timing of gypsum application can affect soil phosphorus mobility and phosphorus leaching. A greenhouse experiment was conducted to address this question and further our understanding of the effect of gypsum addition on soil phosphorus chemistry. For the experiment, two soil types with different background phosphorus levels (low P, high P), and three different time intervals between gypsum and phosphorus fertilizer application (2, 28 and 56 days) were applied. A total of 18 soil columns (L: 15 cm; diam: 10 cm) packed with sieved soil were treated with gypsum (3.9 g) and separated into three sets corresponding to each of the phosphorus application times. An equal number of columns not treated with gypsum were also included to serve as controls. Phosphorus fertilizer (0.34 mg P cm-1) was added as KH2PO4 solution. Rainwater (58 mL) was applied every 2-4 days to generate leachate that was collected and analyzed for ortho-P, total P, and SO4-2. At the end of each time series, the set of soil columns were sliced into 2-4 cm increments, and water extractable and bicarbonate extractable phosphorus (Olsen-P) was determined to examine downward phosphorus movement. Results of the study showed that Olsen-P levels were not affected by the gypsum treatment, indicating no interference of gypsum treatment with the P-supplying capacity of soils. The gypsum treatment reduced water-extractable P levels in the high-P soil, but treatment effect was not significant in the low-P soil. Likewise, in the high-P soil, gypsum treatment resulted in leachate ortho-P reduction during the second and third period of collection. For the low-P soil, there was no significant reduction in ortho-P. Overall, these results indicated that the beneficial effect of gypsum on phosphorus export from agricultural fields is dependent on soil-P status and time interval between gypsum amendment and P fertilizer application.
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The contribution of fishes to phosphorus cycling in lakes /Nakashima, Brian Shyozo. January 1979 (has links)
No description available.
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The synthesis of chiral organosul fur and phosphorus compounds /Friedlander, Barry Terence. January 1980 (has links)
No description available.
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The relationship between chemically analysed phosphorus fractions and bioavailable phosphorus /Bradford, Marie E. January 1985 (has links)
No description available.
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The utility of soil-phosphorus equilibrium studies as an indicator of phosphate concentration in surface and ground water.Horzempa, Lewis Michael 01 January 1973 (has links) (PDF)
No description available.
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The fixation of phosphorus by aluminum and its replacement by organic and inorganic anions.Cole, Carroll Vernon 01 January 1948 (has links) (PDF)
No description available.
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The effects of lime, phosphorus and aluminum on the growth and chemical composition of three legumes.Vickers, John Charles 01 January 1975 (has links) (PDF)
No description available.
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Attributes of Organic Phosphorus Exported from a Central Indiana Agricultural Watershed: Effects of Season and Hydrologic FlowpathPitcock, Rebecca Jo 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The export of phosphorus (P) from agricultural watersheds has been extensively investigated but monitoring efforts have generally focused on inorganic P (Pi or soluble reactive phosphorus [SRP]), the P fraction thought to be immediately available to algae. However, in settings where no-till management is implemented and organic matter accumulates on soil surface, the amount of organic P (Po) in agricultural drainage waters can be significant and may represent another important P source to fuel algal growth in receiving water bodies. From a 2018 monitoring study at a Central Indiana agricultural watershed, measured total P and SRP loss amounted to 1.22 and 0.17 kg P/ha/year, respectively, indicating that the bulk (84%) of P exported from that watershed was in organic form. Results also showed that tile drainage was the main pathway for P transport (96% of Po loss). In light of these observations, the bioavailability of Po in agricultural drainage waters was investigated in 2019, and the effect of hydrologic flow path (surface versus subsurface flow) on the biochemical attributes of Po was examined. In these assessments, the iron strip method and a suite of enzymatic assays were used to gain a better understanding of the chemical composition of the exported Po. Higher concentration of labile Po was consistently measured in tile discharge than in surface runoff (59% versus 38% of the total bioavailable P). Further, the concentration of EHP (enzymatically hydrolysable P), in the form of monoester, diester, and phytate compounds, was highest during the summer season, for both tile and surface pathways. This elevated bioavailability of Po during the summer is a concern because, in combination with favorable water temperature and solar radiation during that period, this could lead to enhanced Po mineralization and release of Pi, resulting in further algal proliferation and continued degradation of water quality. Considering the high prevalence of tile drainage in agricultural landscapes of the US Midwest, this finding underscores the need for further investigation of the impact of land management and climate on the speciation and bioavailability of Po in the region’s agricultural waters.
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A consideration of mechanisms of phosphate fixation and the characterization of phosphate-fixing capacity of soils /Flowers, Jefferson Lee January 1957 (has links)
No description available.
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Phosphorus supplying capacities of some Ohio soils /Thompson, Lyell Floyd January 1952 (has links)
No description available.
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