The intensification of agriculture through Europe has led to a lot of environmental issues. Among these are the increased use of fertilizer and pesticides which also constitutes a risk for many water resources. This is mainly due to the leakage of nitrate and pesticides to the water which makes it unsuitable for drinking. The aim of this study was to investigate whether the nearby agriculture constituted a risk in the catchment of Skottorp. If risks were found, the study was also aiming to evaluate possible measures that could be taken. An additional aim was to find out whether a co-operative agreement between the local authorities responsible for the catchment and the farmers would be a possible solution in case of future problems. For the study, water data related to agriculture was analyzed statistically and interviews were performed with the farmers. The study shows that there are no imminent risks to the water in the catchment related to agriculture, which makes measures unnecessary. If problems would arise in the future the study also shows that co-operative agreements are a suitable course of action.

Field studies examined the strategies of mowing, herbicide, fertility, and all combinations on tall ironweed populations, weed biomass, pasture yield, grazing, economics, and forage quality at three Kentucky locations. Mowing was performed in July 2008 and 2009, herbicide applied in August 2008, and fertilizer applied in September 2008 and 2009 at all locations. Weed populations were measured in 2008, 2009, and 2010, and forage and weed biomass collected in May or June of 2009 and 2010. Herbicide treatments reduced weed biomass at all locations, and reduced tall ironweed stems by 64% or greater in 2009 at all locations. Weed biomass did not differ when comparing all treatments with and without mowing or treatments with or without fertilizer. Forage grass biomass produced was greatest with herbicide plus fertilizer and with the combination of mowing plus herbicide plus fertilizer at all locations in both years. Two years of grazing did not reduce weed populations. Grazing did reduce forage grass and clover biomass at one location, and weed biomass at two locations. Two locations had positive economic returns based on herbicide treatment for weed control and forge yield. Herbicide treatments reduced crude protein at one location and in-vitro true digestibility at two locations.

Abstract available in PDF file. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.

A two-year field study and two incubation studies were conducted to evaluate incorporating urea with a urease and nitrification inhibitor to reduce N2O and N losses from fall banded fertilizer. In each year of the field experiment, five fertilizer treatments (fall banded NBPT-DCD urea, conventional urea, calcium nitrate, spring banded conventional urea and control) were applied at three sites. The effect of incorporating urease and nitrification inhibitors with urea was not consistent in our studies. The application of fall banded NBPT and DCD did not result in greater agronomic performance. Moreover, the addition of inhibitors to urea did not reduce nitrous oxide emissions in the field. The addition of inhibitors resulted in significantly less cumulative nitrous oxide emissions compared to conventional urea in only one of two laboratory experiments. In conditions where fertilizer was not generally susceptible to large losses, the effects of urease and nitrification inhibitors may not be evident.

Fertilizer applications of urea and triple superphosphate (TSP) suffer from low efficiency for corn production. Band or broadcast application of urea with acidic-P fertilizers may increase fertilizer efficiency. Urea and acidic-P fertilizer interactions in soil-fertilizer microsites were investigated using two Quebec soils. Adding acidic phosphates such as TSP and monoammonium phosphate (MAP) to urea reduced pH in microsites, urea hydrolysis, NH$ sb3$ volatilization, and increased soil NH$ sb4$- and NO$ sb3$-N contents. Ammonia loss decreased as P$ rm sb2O sb5$: urea-N ratios increased. Adding urea to P fertilizer increased soil pH and P sorption when using CaCl$ sb2$ as the electrolyte. Urea application increased 0.5 M NaHCO$ sb3$ extractable P. Banding urea with TSP caused dissolution of organic matter in soils, and increased P diffusion and P concentration in soil solution sampled with filter paper or in 1 M KCl extraction. Two years of field experiments demonstrated that banding urea with TSP or MAP increased soil extractable P (Mehlich-3), N and P nutrient uptake, plant growth and development of corn. Greater P fertilizer efficiencies and higher yields were achieved by banding urea-acidic P fertilizers.

No description available.

Nutrient exports, in particular phosphorus, are a major problem for Gippsland and many other regions of the world. This thesis investigates the export of phosphorus in overland flow from pasture-based grazing systems in south-eastern Australia. Initially, field-scale monitoring is used to investigate the forms of phosphorus in overland flow with a view to identifying the primary mobilisation process. It is shown that from a well-managed pasture, phosphorus was primarily mobilised as a result of dissolution rather than physical detachment (erosion) processes. Phosphorus in the overland flow is shown to be predominantly in the dissolved reactive form (DRP). It follows that remedial strategies that rely on physically trapping phosphorus entrained in overland flow (i.e. buffer strips and riparian zones) are unlikely to be effective. The field-scale monitoring data are then used to investigate the structure of phosphorus exports. It is shown that the data conforms to a base-plus-increments model. It is proposed that phosphorus exports can be divided into a base or systematic component that results from a particular land use management system, and an incremental or incidental (preventable) component that is the result of particular management decisions, activities or incidents. (For complete abstract open document)

Thesis (Ph.D.)--Tufts University, 2005. / Chair: Gary Leupp. Submitted to the Dept. of Interdisciplinary Studies. Includes bibliographical references (leaves 185-189). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Thesis (M.S. - Soil and Water Science)--University of Arizona. / Includes bibliographical references (leaves 183-199).