Thesis (Ph. D.)-- State University of New York at Binghamton, Department of Economics, 2009.

Apyrases (NTP-diphosphohydrolases, EC 3.6.1.5) are a family of enzymes that catalyze the hydrolysis of phosphoanhydride bonds of nucleoside tri- and di- phosphates in the presence of divalent cations. In Arabidopsis, AtAPY1 and AtAPY2 function in part as ectoapyrases and have been shown to play important roles in controlling the concentration of extracellular nucleotides, which, in turn, can regulate pollen germination and growth, and cell expansion in diverse plant tissues. We used an NCBI nucleotide blast keyed to Apyrase Conserved Regions (ACRs) to identify five other AtAPYs (3-7). To assess the biological function of each of these five AtAPY genes, the phenotypes of their T-DNA insertion mutants were analyzed. We did not observe any obvious phenotypes from the T-DNA insertion single knockout of any of these genes. However, double knockout mutants of AtAPY6 and 7 exhibited late anther dehiscence and low male fertility. Transmission and scanning electron microscopy revealed that the pollen grains of double knockout mutant of AtAPY6 and 7 are largely deformed in shape and in most cases, the cell walls of the pollen grains are interconnected. Using an AtAPY6-YFP fusion protein in transgenic Arabidopsis, AtAPY6 was localized to intracellular vesicles. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays and promoter:GUS fusion analysis demonstrated that the transcripts of both AtAPY6 and 7 are expressed in mature pollen grains, AtAPY6 is also expressed in the veins and hydathode regions of rosette leaves, and AtAPY7 is expressed in more diverse tissues such as roots, leaves, stems, pistils and sepals. The tissue specificity of AtAPYs 3, 4 and 5 expression was also determined using qRT-PCR assays and promoter:GUS fusion analysis. AtAPY3 and AtAPY4 were primarily expressed in roots but not in rosette leaves. AtAPY5 was expressed primarily in rosette leaves but only weakly in roots. AtAPY5 and AtAPY7 were upregulated when the rosette leaves are wounded or exposed to drought stress. RNA interference (RNAi) was performed to simultaneously suppress the gene expression of AtAPYs 3, 4, 5 to around 10% of that of the wild type. However, we did not observe any obviously altered phenotypes in the RNAi lines. The suppression of AtAPYs 3, 4, 5 by RNAi in the background of AtAPY6 single knockout did not cause any phenotype either. A possible explanation for this lack of phenotype in the RNAi lines is that functional redundancy exists between AtAPYs 3-5 and AtAPYs 1-2 and/or AtAPYs 6-7. / text

The effects of surface applications of poultry manure on pH, exchangeable AI, exchangeable Al saturation and levels of available macronutrients in the surface and subsurface layers were investigated in some acid soils from the KwaZulu-Natal Midlands. Three field sites with a history of long-term applications of poultry manure were compared with adjacent fields where no manure had been applied. Results generally showed an increase in pHwater, pHKCI, exchangeable Ca, Mg, and K and extractable P and a decrease in exchangeable Al and exchangeable Al saturation in the surface soil to the depth to which the manure had been incorporated. Results also provided evidence for substantial downward movement of Ca and Mg into the subsoil layers (i.e. 30-60 cm) and their accumulation in exchangeable forms. There was a concomitant general increase in pHKcl and pHwater and decrease in exchangeable Al and exchangeable AI saturation in the subsoil layers. These results demonstrate that, under field conditions, surface applications of poultry manure can cause the amelioration of subsoil acidity. This is an extremely important finding since subsoil acidity is characteristically extremely difficult and costly to ameliorate. A leaching column study was subsequently conducted to investigate the mechanisms by which surface applications of poultry manure ameliorate both top- and subsoil acidity. The soil used, originating from one of the field sites, had not previously been treated with poultry manure and had a subsoil pHKCI of 4.25 and an exchangeable acidity concentration of 1.79 cmolJkg. Three forms of poultry manure (layer, broiler and free range) were incorporated into the surface 5 cm of soil columns at rates equivalent to 5, 10 and 30 Mg/ha. Columns were maintained in glasshouse conditions for a period of 108 days and over that period they were leached on four separate occasions (receiving a total of 825 mm of simulated rainfall). At the conclusion of the experiment, the soil columns were cut into sections for chemical analysis. Applications of poultry manure to the surface soil markedly increased pHwater, pHKcl, exchangeable Ca, Mg, K and Na concentrations and decreased exchangeable Al levels in the surface 5 cm layer. They also increased the concentrations of soluble C, soluble salts, total Al and organically-complexed Al in soil solution. These effects were most pronounced with layer manure and greater at the higher rate of application. The manure-induced decrease in exchangeable AI, but increase in total AI, in soil solution was attributed to soluble salts, originating from the manure, displacing exchangeable Al into solution where it was subsequently complexed by soluble organic matter. Analysis of subsoil layers (5-15, 15-25, 25-35 and 35-45 cm) at the conclusion of the experiment showed that surface applications of poultry manure decreased concentrations of exchangeable Al in the subsoil but had no effect on pHKCl and depressed values for pHwater. It was suggested that manure-derived urea leached into the subsoil and was then hydrolysed causing an increase in pH and precipitation of exchangeable Al as insoluble hydroxy-AI oxides. Towards the conclusion of the experiment nitrification began to proceed, causing subsoil pHKCl values to decrease back to their original values. Analysis of the inorganic-N content of leachates and soil layers provided circumstantial evidence for this mechanism. High concentrations of soluble salts in the subsoil layers (caused by leaching from the manure) resulted in displacement of exchangeable A13+ and W into soil solution so that the electrical conductivity and concentrations of total and monomeric Al were elevated and pHwater was depressed in the subsoil (15-45 cm) of poultry manure-treated columns. It was concluded that the results underline the opposing effects that poultry manure applications have on (i) raising soil pH and lowering exchangeable Al but at the same time (ii) greatly increasing soluble salt concentrations and thus displacing At3+ and H+ back into soil solution. They also have suggested the importance of the release of N during manure decomposition in influencing soil pH (through the processes of ammonification, urea hydrolysis and nitrification) and therefore other soil chemical properties. It is, however, clear that the long-term effect of surface applications of poultry manure is generally to ameliorate subsoil acidity by raising subsoil pH and lowering exchangeable Al concentrations. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

This study investigates coal discard cover soil fertility and its potential for degradation, particularly in terms of its salinisation and acidification potential. Seven rehabilitated coal discard dumps in the Witbank, Ermelo and Newcastle regions were used as study areas. All areas were rehabilitated with a cover soil layer, revegetated and annually fertilised with nitrate fertilisers, super phosphate, kraal manure and lime. Performance guideline for pH of 5.5-(6.5 i0.5)-7.5 and electrical conductivity guideline of preferably less than 200 mS.rn-' but not higher than 400 mS.m-' were set based on literature information. Soil chemical data from a three-year fertilisation programme were used to assess the fertility of the cover soil surface (0-150mm). Data collected over a three year period as well as additional electrical conductivity and pH measurements from the cover soil surface, subsoil, cover soil/coal contact zone and underlying coal itself were used to assess the occurrence of salinisation and acidification of the cover soil. The soil fertility varied significantly among dumps as well as over the three years. Results indicated an increase in ammonium acetate extractable macro elements (calcium, magnesium and potassium). With the exception of manganese, no micro-element toxicities were recorded. Iron concentrations were slightly elevated in some of the sandy cover soil layers. No increase in soluble nitrogen (nitrate and ammonium) was found and most soluble nitrogen was in the form of nitrates. In general the Bray extractable phosphate increased during the study period. It can be predicted that with the following fertiliser programme increases of exchangeable macro-elements as well as available phosphorus can be expected. The study could not indicate an increase in adsorbed or available nitrogen. Organic carbon was initially not analysed therefore no comments can be made whether organic matter increased. Four of the seven dumps surveyed had comparably similar organic carbon levels to the background samples. Overall the fertiliser programme increased the electrical conductivity and decreased the acidity of the cover soil surface. Acidity and salinity was in general not a problem at the surface of the cover soil and pH was even slightly higher in cover soil samples. The acidity and especially salinity increased at the subsoil and so did the sulphate concentrations. Calcium and magnesium sulphate were predominantly responsible for higher electrical conductivity measurements. The percentage exchangeable sodium was also predominantly less than 2% indicating that sodicity is not currently a problem in cover soil. Soil fertility was satisfactory for vegetation growth and macroelement concentrations were in the correct ratio although calcium was slightly high. An elevated sulphate concentration, in comparison to the natural grassland soils, as well as a high salinity and high acidity in the subsoil layers indicate that salinisation and acidification could deteriorate without proper management. A slightly acidic cover soil can also be attributed partially to its natural acidic pH due to the wellweathered and leach property of burrow pit. Higher than recommended salinity levels were found in subsoil samples but the occurrence of acidification of the subsoil was more dump specific. In relation to acidity and salinity guidelines only the cover soil of one dump was concerning and the larger dumps subsoil acidity and salinity were elevated. The following management strategies are proposed: a) The acidification potential, and therefore the pyrite content of the coal discard must be considered during decisions making on the rehabilitation method (clay barriers), topsoil depth, maintenance and mine closure potential. b) The occasional monitoring of the subsoil's and coal contact acidity is recommended, although not much can be done to stop acidification after cover-soil placement. c) To ensure a more sustained from of nitrogen supplementation over the long term the use of selected legumes should be investigated. Research in Europe and Australia suggested that nitrogen fixation could contribute substantially to the nitrogen for plant uptake. d) The physical properties of the topsoil (bulk density 8 soil compaction) are also being neglected and needs to be assessed occasionally and interpreted together with chemical analyses. Observations in other studies indicate that this could be the most fundamental problem for vegetation growth and not necessarily soil fertility, since soil physical properties could have a major impact on root development. Key words: Coal discard, mine rehabilitation, soil fertility, topsoil degradation, salinisation, and acidification / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2004.

No description available.

Light availability in forest understories is a well recognized constraint on sapling growth, but limitations in soil nitrogen (N) availability, and the link to foliar photosynthetic capacity, typically receive less consideration in describing stand dynamics. My primary hypothesis is that light and soil N availability have species-specific effects on photosynthetic activity and growth, and that together these resources will better define understory development in complex forests. To test these relationships, I examined 1) soil N indices and the tradeoffs between soil fertility and light attenuation in old-growth forest understories; 2) the effects of light and N constraints on understory sapling foliar N concentration (N%), N per unit area (Na), and natural abundance of ¹³C; 3) the effects of light and soil N supply on species growth and photosynthetic activity in a factorial field experiment; and 4) the mechanisms responsible for the stagnation of understory saplings. Soil N indices incorporating dissolved inorganic N and organic N were useful in characterizing differences in N supply among contrasting sites. Understory light availability declined with increasing soil N supply, while understory Abies lasiocarpa had strong correlations between foliar N% and soil N availability, despite shading effects. In partial-cut forests, understory Tsuga heterophylla and Picea glauca x sitchensis had consistent foliar N% across gradients of light availability; in contrast, foliar N% of Betula papyrifera and Thuja plicata declined with increasing shade, which would distort assessments of soil fertility and perhaps contribute to increased mortality of these species in deep shade. Strong correlations between foliar Na and ¹³C or growth increment suggest foliar N per unit area is the simplest integration of light availability and N nutrition on leaf photosynthetic activity. Ontogenic interactions that occur among foliar attributes and tree size in forest understories, especially for saplings < 1 m in height, contribute to time effects on growth patterns and emphasize the need for long-term studies of species autecology and stand dynamics. My experimental manipulation of light and N supply on saplings was ineffective, and future research using natural gradients in site productivity may be more fruitful in defining species response to light and N interactions.

Understanding soil fertility issues in the Middle Mountains of Nepal requires interdisciplinary research, integrating biophysical and socio-economic factors. Soil degradation is associated with a wide range of human activities, natural processes, and the wider economic, political and social aspects of their setting. This study focuses on a in the Middle Mountains and addresses four research questions: What is the current soil fertility status? How is it changing? Why is it changing? and What are the implications for production, sustainability and management? Soil surveys, plot studies, nutrient balance modelling, household questionnaires and GIS mapping techniques are used to address these questions. The overall soil fertility conditions of the study area are poor and appear to be declining under most land uses. Soil pH averages 4.8 ± 0.4 and is below desirable levels for crop production. Soil carbon (0.99 ± 0.5 %) and cation exchange capacity (10.8 ± 4.1 cmol kg⁻¹) are low, and available phosphorus (16.6 ± 18.9 mg kg⁻¹) is a concern given the low pH. Land use is the most important factor influencing soil fertility with khet (irrigated agriculture) showing the best fertility status (pH 5.2, Ca 5.3 cmol kg⁻¹ and available P 21.6 mg kg⁻¹), followed by bari, and grassland, with forest soil fertility being the poorest (pH 4.2, Ca 0.9 cmol kg⁻¹ and available P 0.7 mg kg⁻¹). Soil type is the second most important factor influencing soil fertility, with red soils displaying significantly lower available P than non-red soils (9.8 versus 22.1 mg kg⁻¹). Phosphorus sorption studies indicate the high P fixation capacity of red soils, 1.2 g kg⁻¹ compared to 0.3 g kg⁻¹ calculated for non-red soils. Extrapolation from site specific data to a spatial coverage using statistical analysis and GIS techniques indicates that only 14% of the classified areas have adequate pH, available P and exchangeable Ca, and 29% of the area has a high P fixation capacity (>1.5 g kg⁻¹). Nutrient balance modelling provides estimates of nutrient depletion from the soil pool and raises concerns about the sustainability of upland farming, intensive vegetable crop production and forest nutrient cycling. Dryland maize production results in deficits of 188 kg N, 38 kg P205 and 21 kg Ca per ha furrow slice Rice-wheat cultivation on irrigated land appears to have limited impact on the soil nutrient pool, but the addition of premonsoon maize to the rotation results in deficits of 106 kg N and 12 kg P₂O₅ per ha furrow slice. Rates of soil fertility depletion estimated from differences in soil fertility between land uses indicate substantial N and Ca losses from forest land (94 and 57 kg ha per furrow slice respectively). Land use change, the impact on nutrient flows and relationships between nutrient inputs, crop uptake, nutrient balances and soil fertility provide an understanding of why soil fertility is changing. Historical forest cover data indicates substantial deforestation during the 1950-1960 period, a subsequent reversal in the 1972-1990 period associated with afforestation efforts, and renewed losses in the 1990s. Forest soils receive minimal nutrient inputs and large biomass removal results in a low soil fertility status. Expansion and marginalization of dryland agriculture were noted from 1972-1990, as former grazing, shrub and abandoned lands were terraced and cultivated. Nutrient fluxes indicate that inputs are insufficient to maintain the soil nutrient pool under dryland cultivation due to the high nutrient requirements of maize and nutrient losses through erosion. Nutrient balances for maize and wheat are positively correlated with nutrient inputs but relationships with soil fertility are weak. On irrigated khet lands, cropping has intensified and cash crop production has prompted the use of agrochemicals. Excess fertilization is leading to eutrophication and the high use of agrochemicals is a health concern. Nutrient fluxes on khet fields appear to be sustainable due to the addition of nutrients through irrigation and sediment trapping, but may be insufficient to maintain triple cropping. Grass and shrub land dynamics are characterized by minimal inputs and low productivity. The traditional farming system appears to have been sustainable, but triple cropping and increased vegetable production are threatening sustainability. The transfer of nutrients within the fanriing system is unbalanced. Under intensive production, nutrients on khet land are being depleted, poor farmers are shifting their limited compost inputs from bari to khet fields, and biomass collected from forests, disrupts the natural nutrient cycle. Population growth, land tenure, culture and poverty are the underlying socio-economic factors which influence farming system dynamics, directly impact nutrient inputs, and indirectly drive soil fertility degradation. Population growth rates of 2.6% have contributed to agricultural intensification and marginalization, and pressure on forest resources. The distribution of land is highly skewed with 15% of the surveyed households owning 46% of the land. Women play a central role in soil fertility management through their responsibilities for livestock care, litter collection and compost application, but increasing workloads related to commercial milk production, cash cropping and the off-farm employment of males are a major concern. Agricultural assets, farm gross margins, market oriented production, commercial milk production and off-farm employment provide indicators of economic well-being and are positively correlated with nutrient inputs. Total returns and gross margins are greatest for households growing vegetable crops as part of their rotation, and these households apply significantly more compost and fertilizer to both khet and bari land. Access to land is a key factor driving nutrient management and influencing economic well-being. Land is the main agricultural asset in the study area, khet land is the most productive and khet provides the greatest opportunity of cash crop production. However, given the increased labour demands for triple cropping, vegetable production and commercial milk production, the social sustainability is being threatened. Some 47% of the households were not able to fulfil their basic need requirements from the land they farm. They will have no alternative but to exhaust the capital stock of soil nutrients rather than investing in soil fertility. Maintenance of soil fertility is essential to meet the basic food and resource needs of the growing population. Organic matter management is critical, supplying macro- and micro nutrients, reducing acidification, maintaining soil structure and enhancing microbial activity. Water management and sediment trapping on lowland fields provide additional nutrients on khet land; soil acidity on upland fields and forest land needs to be better managed given the increased fertilizer use on bari and high biomass removal from forests; and the incorporation of N fixing species into agricultural production systems are an option which may provide additional animal fodder and help sustain soil fertility.

Nuo 1996 m. Lietuvos šeimos centruose įgyvendinama sužadėtinių rengimo santuokai programa, kuri yra ruošiama ir nuolat tobulinama atsižvelgiant į šeimos poreikius, galimybes bei problemas, Lietuvos vyskupų konferencijos. Programos tikslus įgyvendina sužadėtinių rengėjai dirbantys Lietuvos arkivyskupijų, vyskupijų, dekanatų ir parapijų Šeimos centruose. Sužadėtinių rengimo santuokai programoje viena iš skaitomų paskaitų temų yra Vaisingumo pažinimas, kurioje sužadėtiniai supažindinami su antropologine žmogaus asmenybės samprata, žmogaus lytiškumu, vaisingumo pažinimu bei natūraliais šeimos planavimo būdais. Kadangi apie natūralų šeimos planavimą ir vaisingumo pažinimą visuomenėje pateikiama labai mažai informacijos, tai ši sužadėtinių rengimo santuokai programoje pateikiama informacija turi būti tikslinga, teisinga ir aiški bei paremta Katalikų Bažnyčios nuostatomis. Tai įgyvendindami sužadėtinių rengėjai turi turėti vaisingumo pažinimo mokymo kompetencijas. Šis darbas yra pirmas bandymas Lietuvoje ištirti sužadėtinių rengėjų santuokai vaisingumo pažinimo mokymo kompetencijas. Atliktame tyrime dalyvavo Lietuvos arkivyskupijų, vyskupijų, dekanatų ir parapijų Šeimos centrų sužadėtinių rengėjai. Nustatyta, kad sužadėtinių rengėjų vaisingumo pažinimo mokymo kompetencijos yra pakankamos dirbti sužadėtinių rengimo santuokai programoje. Atlikto empirinio tyrimo pagrindu pateiktos rekomendacijos sužadėtinių rengėjams dėl jų darbo vertingumo ir vaisingumo pažinimo mokymo... [toliau žr. visą tekstą] / Since 1996 Lithuanian family centers implemented engaged couple marriage preparation program, which is being prepared, and constantly improved in view of the family needs, opportunities and problems, the Lithuanian Bishops Conference. The program aims engaged couple with promoters. Non training program in one of the lectures is fertility awareness, the engaged couple aware of the anthropological concept of the human personality, human Healthy, fertility and natural family planning methods. Because of the natural family planning and fertility awareness in society provides very little information, this marriage engaged couple training program provides information to be appropriate, fair and clear and based on the provisions of the Catholic Church. This is exercising engaged couple drafters must have fertility cognitive skills training. This work is a first attempt to explore Lithuania engaged couple organizers marriage fertility cognitive skills training. Lithuania participated in the study province, diocese, deanery and parish Family Centers sužadėtinių promoters. Found that the makers of fertility engaged couple cognitive training is sufficient competence to work sužadėtinių marriage preparation program. Carried out by empirical research based on the recommendations engaged couple contractors on their merits, and the fertility cognitive training to improve competence.

No description available.

No description available.