Lotsbroverket is the largest wastewater treatment plant on the Aland Islands and it isdesigned for handling wastewater from approximately 30 000 persons. In 2011,Lotsbroverket produced about 2800 m3 of dewatered sludge. The sewage sludge that isproduced is transported to a contractor where it is processed to eventually be used e.g.in the construction of green space. This study aims to investigate available applicationoptions in terms of the sewage sludge that is produced in Lotsbroverket. The main aimis to study the feasibility of using the produced sewage sludge as a fertilizer in theagriculture of the Aland Islands.The sludge already fulfills limit values for heavy metals in accordance with the Act"The Aland Government´s directive on the use of sewage sludge in agriculture." Inorder to clarify the sludge content of pharmaceutical and organic substances it isrequired that the substances are identified and a risk assessment is performed. In theliterature it is found that the risk of human exposure to these substances is low if thesludge is treated appropriately. Suggested appropriate treatment of the plant's sludge isthermophilic digestion whereby also pathogens are killed.The soil of the Aland Islands has a high content of phosphorus. Since 1995 there is anenvironmental program to which currently 95% of the island's farmers are connected.The program controls the use of fertilizers i.e. by setting maximum permitted levels ofphosphorus. Since sewage sludge contains relatively much phosphorus it may be alimitation of the use of sewage sludge on agricultural land of the Aland Island. That iswhy it would be suitable to use the sludge with a different fertilizer in order to obtainthe proper fertilizing properties.In Europe, the use of sewage sludge in agriculture is relatively widespread. Severalcountries have less strict laws regarding the sludge content than the Aland Islands.Because large amounts of fruits and vegetables annually are imported into the island,there is reason to believe that the population already consumes products grown onsludge treated soils. Several of the farmers on the Aland Islands are currently scepticalin terms of using sewage sludge in agriculture, mainly due to uncertainties in the sludgecontent. Regarding the certification of Lotsbroverket in accordance with the Swedishcertification system REVAQ no barriers have been found. To ensure that a certificationis possible, however, further investigations are required.

The increasing input costs for traditional agriculture has led land owners and producers in search of alternative opportunities to increase on-farm income. Replacing agricultural crops with short rotation woody species such as hybrid poplar trees is a form of agroforestry. The objectives of this project were to evaluate: 1) a suitable planting stock for hybrid poplar, 2) the effect of nitrogen (N) fertilizer application and pruning on hybrid poplar growth and, 3) the response of four hybrid poplar clones to fertilizer application and their suitability in the boreal transition ecoregion of Saskatchewan. <p>Two trials were established near Meadow Lake, Saskatchewan where three stock types (cuttings, root cuttings and rooted plugs) of Walker poplar were planted into former alfalfa and pasture fields. Trees were pruned each spring to remove multiple leaders and fertilized in year 2 with 100 kg N ha-1. The presence of roots on rooted cutting and plug stock types was beneficial in terms of hybrid poplar growth and survival. Trees grown from planting stock without roots had survival rates between 32-37% whereas, the survival of trees with roots at the time of planting ranged from 62-81% after two years of growth. Trees that were planted as a rooted stock were 3.5 to 4.2 times greater in height and 4.0 to 5.6 times greater in root collar diameter than trees planted as an un-rooted stock type. The application of fertilizer N decreased tree volumes by 31% at the Alfalfa site and had no effect on tree growth at the Pasture site. The total amount of fertilizer N recovered by the hybrid poplar trees ranged from 1-3% at the Alfalfa site and 3-5% at the Pasture site. <p>The second study involved planting four clones of hybrid poplar (Hill, Katepwa, Walker and WP-69) at the same two sites and applying fertilizer at rates of 0, 150 and 300 kg N ha-1 the first two years. Following the second growing season, Katepwa and WP-69 clones had the highest tree volumes of 750 and 1147 cm3 of the four clones evaluated. The Walker clone had the poorest survival rates (52-56%) compared to the other three clones (> 90% survival). Foliar N levels were not correlated with tree height at the Alfalfa (p=0.1326) or the Pasture (p=0.1063) sites. The relationship between foliar P concentration and tree height was more pronounced during July at the Alfalfa site with an r2 value of 0.7102. The N:P ratios for foliar tissue decreased with increasing fertilizer N application during August at the Alfalfa site. Foliar N:P ratios were the same among fertilizer and clone treatments at the Pasture site in August. <p>Results from this study suggest that rooted stock types increase the successful establishment of hybrid poplar plantations. However, application of N fertilizer may not increase growth of trees if soil N is adequate. Other soil nutrients need to be measured prior to fertilization to determine what nutrients may be limiting plant growth.

Weil in Sachsen die vorhandene Datenbasis zu Schwermetallgehalten in Düngemitteln, Bodenhilfsstoffen und Kultursubstraten im Jahr 2005 zu gering war, wurde ein Projekt mit dem Vorhabenstitel „Bestimmung und Bewertung der Schwermetallgehalte von Düngemitteln, Bodenhilfsstoffen und Kultursubstraten“ durchgeführt, um rechtzeitig Ableitungen für einen sachgerechten und effizienten Hoheitsvollzug in Sachsen treffen zu können. Das Forschungsprojekt beinhaltete folgende Ziele: - Bestimmung von anorganischen Schadstoffen in Düngemitteln, Bodenhilfsstoffen und Kultursubstraten - Bewertung der Analysenergebnisse auf der Grundlage geltender Rechtsverordnungen - Ableitung von Kontrollschwerpunkten für die Düngemittelverkehrskontrolle auf gesicherter Datenbasis. Im vorliegenden Heft werden die Ergebnisse dieses Projektes dargestellt.

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No description available.

The first project involved the evaluation of different times of application on the fertilizer nitrogen recovery (FNR) in the soil-plant system in an irrigated upland cotton system, during two seasons. This was accomplished by using the isotopic dilution technique applying the 15N to microplots. No differences were observed in the total plant FNR, seed and stover, soil and the total FNR among the different 15N application times; however, despite no differences were observed in the plant the FNR value ranged from 30-38%, while the seed exhibited the highest FNR with an average over 50% of the 15N recovered in the plant. In the soil, the obtained average FNR value was over 40% while the total FNR (plant + soil) ranged from 70-80%, being reduced as the 15N application time was delayed.The second project was conducted during two seasons to examine the 15N and bromide distribution pattern in the soil profile as a function of the time of application. 15Nitrogen and bromide were applied to the soil at three different times in a cotton growth cycle; after that, soil samples were taken at the end of the cotton cycle to a depth of 1.80 m., and 15N and bromide recoveries were determined. Slightly higher FNR were obtained with the intermediate application time. The higher FNR were detected in the surface layer (0-30 cm) with an average of 40%. Below 30 cm depth, low 15N recoveries were obtained and even lower below the 60 cm soil layer. Bromide recovery behavior was related to the water movement in the soil profile: as the Br- application time was delayed more of the anionic tracer was found in the top of the soil profile, while less Br- was found in the surface soil for the early Br- application time.

Ultra-narrow row (UNR) cotton (Gossypium hirsutum L.) is a production system using high plant populations in reduced row spacings. The responses of this production system to nitrogen fertilizer have not been fully investigated. Evaluations of yield and earliness of harvest are also important. A three-year study was conducted at the Texas Agricultural Experiment Station farm, Burleson County, TX, on a Ships clay (very-fine, mixed, active, thermic Chromic Hapluderts) and a Weswood silty clay loam (fine-silty, mixed, superactive, thermic Udifluventic Haplustepts). A split plot design was used. Nitrogen fertilizer rates of 0, 50, 101, and 151 kg N ha-1 were applied as the whole plots and row spacings of 19, 38, and 76 cm were established as the split plots. Data included lint yield and yield components, as well as earliness of crop maturity and earliness-related parameters such as boll distribution. Lint yield was increased by higher nitrogen rate. There was no nitrogen rate by row spacing interaction on lint yield, implying fertilizer rates do not need to be changed for UNR systems. Reductions in row spacing did not significantly affect lint yield in any year. Responses such as reduced bolls per plant, increased plant populations, increased ginout, and decreased boll size were often significant and combined to allow the crop to maintain equivalent yields as row spacings were reduced. The slight UNR earliness advantages were probably due to changes in boll distribution. Based on these results, increases in lint yield and earliness may not reliably contribute to the profitability of UNR cotton.

This thesis examines the influence of nutritional phosphate (Pi) deprivation on extracellular proteins secreted by the model plant Arabidopsis thaliana. Initial studies compared the secretome of Pi-sufficient (+Pi) versus Pi-deficient (-Pi) Arabidopsis cell cultures by 2-dimensional gel electrophoresis. Mass spectrometry identified 18 different secreted proteins that were upregulated by at least 2-fold by –Pi Arabidopsis. They were predicted to function in Pi scavenging, cell wall and ROS metabolism, proteolysis, and pathogen responses. The relationship between mRNA levels and relative amounts of selected secretome proteins was assessed. The results indicate that transcriptional control is but one of many factors contributing to Arabidopsis Pi starvation responses and highlight the importance of parallel biochemical and proteomic studies of –Pi plants. Three purple acid phosphatase (APase) isoforms were fully purified from the culture media of –Pi Arabidopsis cells and identified as AtPAP12 (At2g27190) and two AtPAP26 (At5g34850) glycoforms. As each purple APase exhibited broad substrate specificities and pH-activity profiles, it is hypothesized that their combined activities facilitate Pi scavenging from soil-localized organophosphates during nutritional Pi deprivation. AtPAP26 is dual-targeted during Pi stress since an earlier report demonstrated that it is also the principal intracellular (vacuolar) APase upregulated by -Pi Arabidopsis. The results indicate that differential glycosylation influences AtPAP26’s substrate specificity and subcellular targeting. An atpap26 T-DNA insertional mutant lacking AtPAP26 transcripts and immunoreactive AtPAP26 polypeptides exhibited: (i) 9- and 5-fold lower shoot and root APase activity, respectively, which did not change in response to Pi starvation, (ii) a 40% reduction in secreted APase activity during Pi deprivation, (iii) 35 and 50% reductions in free and total Pi concentration, respectively, in shoots of –Pi plants, and (iv) impaired shoot and root development when subjected to Pi deficiency. By contrast, no deleterious influence of AtPAP26 loss of function was apparent in +Pi plants. The results establish a firm role for AtPAP26 in the acclimation of Arabidopsis to Pi deficiency. The identification and functional characterization of secreted proteins upregulated by –Pi Arabidopsis is relevant to applied efforts to engineer Pi-efficient transgenic plants, needed to minimize the input of expensive, unsustainable, and polluting Pi fertilizers in crop production. / Thesis (Ph.D, Biology) -- Queen's University, 2010-04-28 17:20:46.892

Fertilizer applications of urea and triple superphosphate (TSP) may affect availability of plant nutrients in the soil through alteration of soil pH and sorption-displacement effects. The objectives of this experiment were to evaluate urea and TSP effects on nutrient availability to soybean (Glycine max L.). Field experiments were carried out on three Quebec soils; a Chicot sandy clay loam (Gleyed Melanic Brunisol), an Ormstown silty clay loam (Luvic Gleysol) and a Ste. Rosalie clay (Humic Gleysol). Three levels of TSP (0, 40, 80 kg $ rm P sb2O sb5 ha sp{-1}),$ and three levels of urea (0, 25, 50 kg N ha$ sp{-1})$ were incubated in the field and sampled at 4, 8, 12, and 16 weeks. Added TSP increased extractable P and decreased NO$ sb3$-N. Overall, alterations in nutrients other than N and P with added TSP or urea were not agronomically significant. There was increased concentration of N, P and Mo in soybean in some soils due to TSP application. Added urea increased Mg concentration in soybean. The concentration and uptake of Mo was positively correlated with soil extractable P and Mg. Consequently, application of TSP and urea together improved Mo uptake in the Chicot soil, while in slightly acid soils, Ormstown and Ste. Rosalie, TSP alone increased Mo uptake.

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.