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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Availability of phosphorus in rock phosphate-sulfur fusions

Fenster, William Ernest, January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 51-52.
62

Polonium-210 contents of plant tissue and the use of metal ammonium phosphates as vegetable crop fertilizers Polonium-210 analyses of vegetables and tobacco and associated soils : metal ammonium phosphates as vegetable crop fertilizers.

Erhardt, Wilfred H. January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.
63

Long-term effects of copper rich swine manure application on continuous corn production

Anderson, Martha Ann 01 November 2008 (has links)
Three long-term field experiments were established in the spring of 1978 and continued through 1988 to evaluate corn (Zea <i>mays</i> L.) response to high Cu levels from Cu rich swine manure and CuS0₄ applications. The field research was conducted on soils with diverse properties, i.e., on a Bertie fine sandy loam (Aquic Hapludults), a Guernsey silt loam (Aquic Hapludalfs), and a Starr-Dyke clay loam (Fluventic DystrochreptsTypic Rhodudults). Three treatments in the long-term field experiments on the three soils were a control, annual applications of eu as eu rich swine manure, and annual applications of Cu as CuS0₄ equivalent to that in the manure. After the 11 years, 1109 mt ha⁻¹ of wet Cu rich swine manure were applied for the manure treatment. The Cu rich manure contained an average of 1316 mg Cu kg⁻¹, An average of 325 kg Cu ha⁻¹ added to the soils from the manure application over the 11 years exceeded U.S.E.P.A. guidelines for safe copper loading levels for cropland by 45 kg ha⁻¹. Copper concentrations in corn ear leaves were within the normal range of 3 to 20 mg kg⁻¹ where the 325 kg Cu ha⁻¹ were applied to the soil as either Cu rich manure or CuS0₄. Concentrations of Cu in the grain were also in the normal range of 1 to 5 mg kg⁻¹ where the high level of the two Cu sources was applied to soils. There was no decrease in corn yield on the three soils from application of either Cu source. / Master of Science
64

Nitrate concentration in cereal stems and its use in evaluating rotations and predicting nitrogen fertilizer requirements

Papastylianou, Ioannis. January 1980 (has links) (PDF)
No description available.
65

Addition of organic materials to soil in Hong Kong and their effects on crop growth, microbial activity and the soil-nitrogen status.

Yau, Boa-ling, Bonnie. January 1971 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1972. / Typewritten.
66

The effects of surface-applied poultry manure on top- and subsoil acidity and selected soil fertility characteristics.

Judge, Angus. January 2001 (has links)
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.
67

Investigation of the blade roller for organic green manure management

Vaisman, Iris 22 September 2010 (has links)
The objective of this study was to investigate the effects of using the blade roller for no-till/reduced tillage in organic green manure management. The study was conducted in Carman, Manitoba and Oxbow, Saskatchewan. In the spring, a pea/oat intercrop was seeded as a green manure. The green manure was terminated by rolling, tilling, or a combination of the two. The following spring, spring wheat was seeded. In the year of the green manure, measurements taken included: biomass, soil nitrogen, and ammonia emissions. In the year of the wheat, measurements taken included: soil cover, soil moisture, weed competition, soil nitrate-N, and wheat biomass. Results showed increased soil cover, minimal effect on soil moisture, delayed wheat development, an effect on weed communities, reduced rate of nitrogen release, and reduced wheat yield. No-till green manure management can therefore provide benefits of soil conservation and nitrogen conservation but may result in decreased wheat yield.
68

The sealing of soils by manure /

Barrington Thauvette, Suzelle January 1985 (has links)
No description available.
69

Investigation of the blade roller for organic green manure management

Vaisman, Iris 22 September 2010 (has links)
The objective of this study was to investigate the effects of using the blade roller for no-till/reduced tillage in organic green manure management. The study was conducted in Carman, Manitoba and Oxbow, Saskatchewan. In the spring, a pea/oat intercrop was seeded as a green manure. The green manure was terminated by rolling, tilling, or a combination of the two. The following spring, spring wheat was seeded. In the year of the green manure, measurements taken included: biomass, soil nitrogen, and ammonia emissions. In the year of the wheat, measurements taken included: soil cover, soil moisture, weed competition, soil nitrate-N, and wheat biomass. Results showed increased soil cover, minimal effect on soil moisture, delayed wheat development, an effect on weed communities, reduced rate of nitrogen release, and reduced wheat yield. No-till green manure management can therefore provide benefits of soil conservation and nitrogen conservation but may result in decreased wheat yield.
70

Nitrate concentration in cereal stems and its use in evaluating rotations and predicting nitrogen fertilizer requirements / Ioannis Papastylianou

Papastylianou, Ioannis January 1980 (has links)
xx, 271 leaves, 28 leaves of plates (3 col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Agronomy, University of Adelaide, 1981

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